Tag Archives: Tony Seba

Testing Tony Seba’s EV Predictions 19 (How Low Could Battery Prices Go?)

As discussed in my last post, the price of an electric vehicle (EV) battery will play a central role in determining EV sales versus internal combustion engine (ICE) vehicle sales through to Tony Seba’s forecast horizon of 2030.

In that post, I also noted that the average sales price of a vehicle in the USA was $36,113 in 2017. Further, I roughly estimated that the cost of an ICE powertrain plus fuel tank was in the order of $3,400 in that year, or roughly 9.5% of the retail sticker price for an average car. Finally, I made the heroic assumption that an EV powertrain without the battery would cost about $1,000. Accordingly, if the powertrain plus battery of an EV is to come down to the cost of an ICE powertrain plus fuel tank, then the battery most come down to $2,400. Is that possible?

To have an EV completely without range anxiety, and given current miles per kilowatt hour (kWh) of battery efficiency, I speculated in another post that a 100 kWh battery would be required. Based on these assumptions, we can back out the target price of the battery (measured per kWh) in order for EVs to match ICE vehicles in price; in other words, $2,400 divided by 100 kWh, or $24 per kWh.

As mentioned in my last post, Bloomberg New Energy Finance (BNEF) estimated that the weighted average cost of an EV battery in 2017 was $209 per kWh. BNEF analysts estimate that this number will come down to $100 by 2023 and Tesla believes that it can hit the $100 number in 2020. But how much lower that $100 per kWh can a battery pack go? Is $24 a possible 12-year target?

Before we get too despondent over hitting the $24 figure, it should be noted that the industry has, in general, been far too pessimist about the speed of cost reductions with respect to battery-pack pricing. The chart below was taken from a September 2017 article titled “Cost Projection of State of the Art Lithium-Ion Batteries for Electric Vehicles Up to 2030” by Berckmans et al in the academic journal Energies. As of 2018, Tesla is already well below $200 per kWh. So those past predictions have turned out far too pessimist.

Sales Price Prediction Lithium-Ion

Nonetheless, while Tesla/Panasonic, the market leaders in battery technology are still securing both technology-driven cost savings and economies-of-scale related cost savings, there are limits as to how far they can go in battery cost reductions.

The most important limiting factor is raw material costs. The table below gives a breakdown of the cathode component alone in a battery pack as provided by Total Battery Consulting’s Dr. Menahem Anderman in a Seeking Alpha article. So the cathode materials alone come to $46 per kWh before we add in the anode, electrolyte, separator and then all the battery management software and hardware required to stop the battery overheating and to maintain the battery’s life.

Cathode Cost

True, the most costly material used in a Tesla battery is cobalt, and the use of cobalt has been on a declining trend.

Cobalt Usage

Moreover, Elon Musk made this statement in the company’s 2018 Q1 conference call (a Reuters article on this theme can be found here).

“we think we can get the cobalt to almost nothing”

Yet even if we near eliminate cobalt, the lithium and nickel alone will prevent the battery pack price getting anywhere close to $25 per kWh.

More realistically, it may be possible to achieve a $50 per kWh battery sometime after 2025. For a 100 kWh vehicle, $50 per kWh gives a total battery pack cost of $5,000, yet we are trying to seek parity with ICE vehicle pricing by producing a battery pack for around $2,500. What is to be done?

There are two possible solutions. First, a leap in battery chemistry could be achieved such that both energy density (kWh per litre) and specific energy (kWh per kg) jump higher without the need for more raw materials. Solid-state batteries appear the lead contender to become the next generation commercial battery technology some time in the mid-2020s. Apart, from eliminating cobalt, solid-state batteries would boost both energy density and specific energy and, once the technology beds down, these batteries have the potential to push battery costs much lower.

Tony Seba, however, is not looking for a technology breakthrough. A major component of Seba’s EV thesis relates to technology cost curves, and his presentations frequently feature the slide below (for example here). The curve is exponential and shows a 16% decline in costs per annum. Moreover, the technology cost curve is really an amalgam of cost-cutting achieved through economies of scale and through ‘learning by doing’. In short, these are incremental cost savings, not revolutionary cost savings.

Projected Battery Cost

For existing lithium ion technology, there are theoretical reasons why both energy density and specific energy cannot go above certain levels that we are fast approaching. Further, while we may be able to eliminate certain battery materials we cannot eliminate all the expensive battery materials. The only way we can stay on this 16% per annum downward-sloping exponential curve is for us to jump into a new generation of battery technology. This may, or may not, happen within Tony’s 2030 forecast horizon, but it is certainly not a given.

OK, let’s assume that we don’t get solid state out of the lab and into the factory in the forecast time horizon and we can’t get battery pack costs down to $25 per kWh. The Tony Seba thesis is that EVs will rule the world by 2030. Should we laugh at that goal? Not quite. It is possible that if we loosen our battery size condition at which range anxiety is eliminated, we may still get there. And one way this could be done is through introducing dynamic charging, or charging in motion.

Currently, the 75 kWh battery in a Model 3 can keep the car on the road for 310 miles. Accordingly, a 50 kWh battery will keep it on the road for around 200 miles. But to eliminate range anxiety,  I posited in a previous post that we needed a car to go 450 miles on one charge. One way we can square this particular circle is to charge a car while it is moving, and Qualcomm is developing a dynamic vehicle electric charging (DEVC) system called Halo that does just that.

The Halo system can charge your car at a maximum rate of 22 kilowatts. Therefore, if you travelled over this system for one hour continuously you theoretically could charge your car by 22 kWh. Do that a number of times over a long distance journey, say for 3 hours in total, and that would add 66 kWhs. So now our 50 kWh EV can more than double its range to above 400 miles and bye bye range anxiety. Of course, assuming your EV driver is doing 60 miles per hour, three hours of driving translates into roughly 180 miles, or 290 kilometres. That is considerably longer than the Qualcomm 100 metre DEVC test track. And, of course, we haven’t considered the cost of the required infrastructure.

The other alternative is to bring your car to a stop, but have access to a mega super charger such that an extra 100 miles could be added in minutes. If our 50 kWh Tesla Model 3 can do around 200 miles on one charge, then to add 100 miles you would need a charger to add 25 kWh. A new charger by ABB boasts a charge rate of 350 kW. At that rate, 100 miles could be added in about 5 minutes. Such mega fast charging rates provide further challenges for battery technology, since they have the potential to severely damage a battery if not managed properly. Indeed, no existing EVs on the road could currently cope with such charge rates. Nonetheless, the next generation of high-end German EVs appear to be designed to take advantage of a new generation of super chargers, with Porsche first to market with its Mission E vehicle to be launched in late 2019. Given time, this technology is likely to trickle down to mid- and low-end EV models.

In conclusion, getting the price of a battery down to a point where EVs can blow away ICE vehicles on price is not a given. Indeed, it is very difficult to see how incremental improvements in current battery technology alone can vanquish the internal combustion engine. Nonetheless, it is just possible that the combination of a slightly smaller battery coupled with new charging technology could do the job. At that point, EVs should match or exceed ICE vehicles in every area of the car purchase decision, so setting up the possibility that the market will tip and EV domination was arrive at an unprecedented pace.

Finally, the word ‘unpredicted’ could perhaps substitute for the word ‘unprecedented’ since no mainstream organisation or company is forecasting EV sales to vanquish ICE vehicle sales by 2030. The differing EV sales scenarios will be the subject of my last post in this series.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

 

 

 

 

 

Testing Tony Seba’s EV Predictions 18 (It’s the Price of the Battery, Stupid)

A few posts ago, I looked at the reasons why we buy a car and highlighted mobility, aesthetics and status-signalling as key factors. Those are the ‘wants’ in the purchase decision. But the purchase decision is also determined by ‘constraints’, the most important of which is cost. At the time of purchase, we have a current budget constraint, which is the sum of money available to buy a car, and a future budget constraint which is the sum of money we have available to fuel it, maintain it and, ultimately, replace it as it wears out.

I also stated that for Tony Seba to achieve the penetration rates shown in the chart below (culminating in 95% of auto sales being electric vehicle, EV, by 2030), the EV must match or excel the internal combustion engine (ICE) vehicle in every category of ‘wants’ or ‘constraints’. In this post, I am going to focus on an auto buyer’s current budget constraint: price. So if you have a choice between buying an EV or an ICE and the EV matches or exceeds the ICE in mobility provision, aesthetic, status signalling, fuel costs, maintenance and depreciation, you almost definitely will buy that EV if it also matches the ICE in price.

Seba Central Scenario

This post in some ways mirrors the previous one as, in effect, we are comparing the EV powertrain plus battery against the ICE vehicle powertrain plus fuel tank. Previously, the comparison was mostly with respect to weight, but also considered volume. This time we are focussed on cost. Note, however, that for all those parts of the car that don’t relate to the powertrain or energy source, we should have near parity. True, the structural integrity of an EV must be designed to protect the battery and this may uplift costs. But, similarly, the cradling of a large internal combustion engine at the front or back of a car will also pose challenges for a designer and have its own expense. For the sake of simplicity, I am viewing those EV versus ICE costs as a wash. So really this is a competition between a battery plus electric motor and a internal combustion engine plus all its complementary parts including the fuel tank.

Let us start with the most expensive component within the EV: the battery. Again, we have to very careful over what we are comparing here: the battery cell, battery panel or battery pack? I prefer to focus on the ‘all in’ battery pack cost, which includes the heat regulating materials, battery management control panel, ancillary wiring and everything else that is required to connect the battery cells to the electric motor.  As stated before, the battery pack size is determined by the number of  kilowatt hours (kWh) of energy that can be stored.

In a prior post, I speculated that to almost completely eliminate range anxiety, our next generation EV would need to increase its range from the current Tesla Model 3’s 310 miles to around 450 miles. Note again that I am talking here about an EV range that will in effect eliminate range anxiety for almost all drivers, so allowing new sales of EVs to reach a penetration rate of 95% by 2030. Most drivers will likely be happy with any range north of 300 miles, but this series of posts is setting a much stricter criteria of not ‘most’ drivers but ‘nearly all’ drivers.

We are now ready to start applying some numbers. Let us start with the average battery pack cost per kWh. The most authoritative figure for this cost is provided courtesy of Bloomberg New Energy Finance (BNEF)’s annual survey of battery pack costs. At the end of 2017, this figure had fallen to $209 per kWh.

Battery Pack Costs

In my last post, I suggested that in order to get an initial range of 450 miles, a 109 kWh battery would be required. At $209 per kWh,  a 109 kWh battery pack would cost $22,781. That is a lot of money for just one component of a car. BNEF analyst James Frith predicts, however, that battery pack costs will fall to $100 or below by 2025. At that price, a 109 kWh battery will cost $10,900. What does that look like as percentage of the total cost of a car?

Although China has overtaken the US as the largest market globally for new car sales, I am just going to run the numbers for US auto sales since granular data is unavailable for China. According to the Kelly Blue Book, the average cost of a new car in the United States was $36,113 as of end 2017.

Kelly Blue Book

So a 109 kWh battery is 30% of the price of the average new car sold in the USA. To give us some further perspective, Tesla aims to sell an entry level Model 3 with a 50kWh battery at a price of $35,000. At a cost of $100 per kWh, the battery in that particular Tesla would be around 14% of the cost of the car (and we haven’t added in the electric motor yet). How do these numbers compare with an ICE powertrain? Let us drill down into the cost of a car a bit further.

From the average new automobile transaction price of $36,113, we need to subtract dealer gross margins on new car sales. These average around 6% (source: here). Accordingly, the manufacturer’s average auto sales price pre dealer mark-up comes in at roughly $34,000.

New Vehicle Gross Margin

Next, we need to subtract the manufacturers operating profits to get the cost to manufacture a car. PWC has the average operating profits at the manufacturers at around 6%. Subtracting these margins, the average cost to manufacture an average car comes down to around $32,000.

Surprisingly, I really struggled to find a good breakdown of physical materials and components as a percentage of the cost of a car. The best I could find is the chart below.

Auto Cost Breakdown

Forty-seven percent of the post dealer and manufacturer profit figure of $32,000 gives a rough figure of $15,000 for the physical material that makes up a car.  A 2012 report by McKinsey that forecasts through to 2020 suggests that this figure of $15,000 is about right. In the graph below, the total vehicle parts cost given by McKinsey is $13,400. That, however, is for 2012.

Assuming the percentage breakdown of different categories of parts is the same now as 2012, we can see that the internal combustion engine powertrain accounts for 22% of total parts, or $3,300 out of $15,000. I’m going to add on to that $100 for the fuel tank to give a total of $3,400 for powertrain plus fuel source.

Auto Component Breakdown

Following this line of thought, we next need to price an electric motor, the principal powertrain of an EV. That task is even more difficult as the manufacturers appear loathe to disclose any pricing information on the two main EV drivetrain technologies: AC induction motors or permanent magnet motors. We do know, however, that the number of components that go into these motors is vastly fewer than go into an internal combustion engine. Further, an EV powertrain does not need a gear box, exhaust system and so on. As a heroic assumption, I will assume that the EV drive train costs a little less than one third of the ICE drive train, or $1,000.

With all these numbers, we are now in a position to compare an ICE powertrain plus fuel tank with an EV powertrain plus battery. The former costs $3,400 now against a 109kWh EV power train plus battery costing $11,900 in 2025. That suggests that a mid market EV with a long range will still sell at a 25% premium to its ICE counterpart even after battery pack prices have halved. And to repeat again, for EVs to do to ICE vehicles what digital cameras did to film cameras, EVs need to either match or exceed the old technology in every category of consumer preference. A 25% price premium is not matching.

Nonetheless, all is not lost for Tony’s 2030 prediction of total dominance of EVs over ICE vehicles by 2030. First, the application of lighter weight materials in car manufacturing should allow auto makers to eke out more miles per kWh, so allowing a smaller battery. Second, more dynamic charging methods could also permit ‘on the go’ charging tops-ups that would also allow the battery size to shrink.  Third, 2025 is not 2030, so the battery price will have further to fall. Fourth, the Bloomberg prediction of $100 per kWh for the battery pack price in 2025 relates to a waited average price across all EV makers. Market leader Tesla is looking at a battery pack price of $100 per kWh by 2020, giving that firm another 10 years of falling battery costs before the 2030 prediction deadline arrives.

In my next and penultimate post of this series I will look at the question of how low battery prices could go and whether dynamic charging developments could allow EVs to get away with smaller batteries yet still banish range anxiety.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

Testing Tony Seba’s EV Predictions 17 (More about Batteries)

In my previous post, I suggested that we are on the cusp of putting electric vehicle (EV) range issues behind us. Two distinct technologies are overcoming the range problem: the growth of fast charging networks and the rise in the energy capacity of EV batteries. In this post, we are going to drill further down into the energy capacity issue.

In the past, the battery constraint has been size and weight. Producing a battery that can deliver 400 or 500 miles of continuous driving is relatively easy: you just make the battery ever bigger. The problem has been delivering the required energy capacity within a sensibly sized and weighted unit. The Tesla Model 3 battery comes in at 478 kg, contains 75 kilowatt hours (kWh) of energy and can propel the car 310 miles between charges according to the US Department of Energy. In the Tesla Model 3, for every 1 kg of battery we get 157 watt hours (Wh). This is called the specific energy of the battery, or the gravimetric energy density, and is measured in watts-hours per kilogram.

I mentioned that the Model 3 has a 478 kg battery. We are really talking about the battery pack here, which incorporates a number of battery modules, which in turn incorporate a number of battery cells. As is the case of many things EV, we are frequently faced with the problem of comparing apples and pairs. That is, if we want to compare specific energy figures between vehicles, we need to compare like with like: battery pack with pack, module with module or cell with cell. The building of a battery, from components, to cells, to modules, to the pack can be seen in the illustration below (source: here):

ValueChainEVBatteries

The combination of the battery elements is a complex interlocking process involving a lot of different disciplines such as chemistry, electrical engineering and mechanical engineering. And it also involves trade-offs. Securing specific energy gains in one area can result in losses in another.

BatteryProcess

For example, the Tesla Model 3 uses state-of-the-art Panasonic ‘2170’ battery cells that are likely the highest specific energy battery cells deployed in mass production cars. (Note that the 2170 number represents the dimensions of the battery cell not the battery chemistry; 21 mm is the diameter and 70 mm the length.) But the battery chemistry employed in these cells is quite difficult and requires a sophisticated cell management and heat control system to prevent thermal runaway; i.e., the battery catching fire. Obviously, the more sophisticated and complex the cell management system, the more the overall battery pack is bulked up.

Of course, by definition, battery cells have a far greater specific energy (gravimetric energy density) than the battery pack since all the battery pack parts surrounding the cells have zero specific energy. In the Tesla Model 3 tear down that I referred to in a previous post, Jack Rickard extracted the four modules that go into the Tesla Model 3 battery pack. They are slightly uneven in size. Two of the modules contain 1,058 cells and two contain 1,150 cell, so the overall battery pack has 4,416 cells in total. Jack also weighed the modules: in total they came to 362 kg. So with usable energy of 75 kWh, the modules alone have a specific energy of 75 kWh divided by 362 kg, which translates to 207 Wh/kg (Jack blogged about this tear down here). From the top of the post, remember that the specific energy of the battery pack in its entirety was 157 Wh/kg.

We can go even further down to the specific energy of the individual cells. Before we do that, here is a short video of a Tesla Model 3 ‘2170’ cell being dissected:

Surprisingly, I’ve struggled to find an official weight for each individual battery cell. From a Tesla forum conversation, I have seen a figure of  66 grams quoted, but I can’t verify this. Until I get a definitive number, however, I will run with 66 grams as it likely to be only a few grams out. So if we have 4,416 cells each weighing 66 grams, that gives us a total weight for the cells alone of 291 kg. This time, let’s divide the total energy of the battery pack, 75 kWh, by this new figure. The results is that each cell has a specific energy density of 257 Wh/kg. Compared with the theoretical maximum specific energy density of around 400 Wh/kg, you can see that there is the potential for some future efficiency gains but not transformational ones.

BatteryMooresLaw

In the Model 3, Tesla has a car that can compete with ICE rivals such as Audi, BMW and Mercedes, but for Tesla to utterly dominate all its competitors it would be helpful if we could get its driving range even higher than 310 miles between charges. How easy is it for Tesla to do that within the existing battery chemistry limitations highlighted above?

First, let’s focus on the non-cell components in the battery pack. We already established that the battery cells weigh 291 kg in total. If we take that number away from the overall battery pack weight of 478 kg, then the non-cell components weigh 187 kg. Let’s say that through mechanical and electrical engineering incremental improvements, we reduce the non-cell weight of the battery by 12% per annum for three years; in other words by roughly one third. That will free up about 65 kg out of that 187 kg.

Next we allocate that 65 kg to install more cells. So the cell weight goes from 291 kg to 356 kg. That’s a 22% increase. If we hold the specific energy of the cells constant at 257 Wh/kg, we now have a 91.5 kWh cell pack that should give us a range of 378 miles.

Turning now to the battery chemistry, we recognise that specific energy improvements are harder to achieve in this area than improvements in electrical or mechanical engineering. So for the cells, let’s assume Tesla and Panasonic improve the specific energy by 6% per annum for the next 3 years. That will result in specific energy going from 257 Wh/kg to 306 Wh/kg, an improvement of 19%. With our 19% improvement, the battery now goes from 91.5 kWh to 109 kWh and range improves from 378 miles to 450 miles between charges. At a 450-mile range, I declared in my previous post that all worries over EV range would disappear.

In a perfect world, I would like to not only get up to a 450-mile range but also shrink the battery weight and size. But for that, we probably need to wait for a jump in battery technology that delivers specific energy north of 500 Wh/kg. There are a variety of advanced batteries in the pipeline that aim to do just that as can be seen below. Nonetheless, we have yet to see any that are close to commercial production.

FutureBatteryChemistry

The conclusion of this post, nonetheless, is that even with only incremental improvements in existing technology, EV powertrains (plus their batteries) are getting very close now to matching or exceeding ICE powertrains (plus their fuel tanks) in every single area of performance. Throughout this discussion, however, I have left out one critical parameter: cost. That will be the subject of my next post.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

 

Testing Tony Seba’s EV Predictions 16 (Range Anxiety and the Need to Wee)

When Jack Rickard pulled the battery out of a wrecked extended range Model 3 in a previous post, it weighed in at 478 kg. We are talking here of a 75 kilowatt-hour (kWh) battery. If you have a high tolerance for ‘slow video’ then you can see Jack, together with Bill from Ace Hardware, Linden, Tennessee, extract the battery from a Model 3 (I rather like Jack’s vlogging style, but then perhaps I should get out more).

Let us put this battery into some kind of context. If we divide the energy storage of the 75 kWh Tesla battery Jack Rickard extracted by its weight of 478 kg we get 0.157 kWh per 1 kg of weight. Let’s change our unit from kilowatts to watts: so we get 157 watt hours (Wh) per kg. Note we are talking about the entire battery here, not the battery cells.

The measure of the amount of energy per unit of weight is referred to as the specific energy or gravimetric energy density. If you are building EVs you want to have as high as possible specific energy for your battery. Each technological advance then allows you to either store the same amount of energy for less weight, or store more energy for the same amount of weight.

When you compare EVs with internal combustion engines (ICEs), the EV basically wins hands down with respect to the delivery of power. So boosting the specific energy of the battery is about having more energy in your battery (rather than power). This, in turn, gives your car more mileage range. Indeed, a critical goal in battery development is to boost specific energy to such an extent that mileage range becomes a non-issue. Nonetheless, even if your battery can deliver all the possible miles that an owner could wish to drive in one sitting, an incentive still exists to boost specific energy even further because that would allow you to continually shrink the battery.

Keep in mind that the Model 3 Tesla battery Jack extracted weighs 28% of the overall vehicle weight. So let’s do a thought experiment and imagine that Tesla doubles the specific energy of the battery to 300 watt hours per kg (wh/kg).

The current Tesla Model 3 has a range of 310 miles according to the US government’s Environment Protection Agency (EPA); pretty good, but I should think the consumer is greedy for more. Let’s decide to increase the mileage range by 50% to around 450 miles between charges. With our new 100% specific energy improved battery we could deliver 450 miles plus shrink the battery by 25% to about 325 kg. We are, in effect, lightening the car by over 100 kg. And, if we are lightening the car by 100 kg, we are making it more efficient.

The extended-range Model 3 weighs in at 1,730 kg; if we drop 100 kg in weight, that translates into a weight saving of around 6%. And given a chunk of the battery’s energy is used up lugging the battery itself around, every time we shrink the battery we release energy that can be used for moving the rest of the vehicle and its occupants. This, in turn, allows us to shrink the battery further. In other words, we have a nice little positive feedback loop emerging here.

Specific energy is not energy density. The term energy density, or volumetric energy density, refers to the energy stored per unit of volume, or watts per litre (wh/l). In an ideal world, I would have loved it if Jack had also taken the dimensions of the extracted Tesla battery as well. Then we could have worked out a real-time energy density number for the Model 3 battery. In the chart below, however, you can see that a linear relationship exists between specific energy (termed here gravimetric energy density) and volumetric energy density. Therefore, as we achieve specific energy enhancements, we generally get energy density improvements as well.

SpecifiEnergyVEnergyDensity

Put another way, as you lighten the battery you will also reduce its size. And every time you do that, the size of the total drivetrain, including energy source, gets more competitive versus the ICE drivetrain plus fuel tank. Note that the EV has already won in the configuration competition with an ICE vehicle. You have far more latitude in arranging your drivetrain components with an EV since you are just connecting them up with wires. No crankshaft or gear box required.

Let’s talk a bit more about range. We’ve established that the extended range Tesla Model 3 can drive around 310 miles on a fully charged battery according to US government statistics. So we get 3.85 miles per kWh. Speed limits in the USA vary by state, but the highest speed limit is found in states like Texas and comes in at 75 mph. So our 310 mile range for the Tesla translates into roughly 4 hours 10 minutes of driving time in the high-speed-limit states, and that is assuming the entire journey is at the maximum speed limit.

Given the average motorist doesn’t wear adult diapers while driving, he or she will periodically need to get out of the car to urinate or defecate. Moreover, I propose that the need for a wee is the limiting factor here, so the act of urination is our boundary constraint (apologies to irritable bowel sufferers). According to WebMD, the average adult urinates between once every two to four hours. So I will take an ‘iron bladder’ as my example Tesla driver. Bottom line, the car will not run out of energy before the girl or boy has gotta go.

Nonetheless, we have to think about how long it takes to charge the car up again. And then we need to plug that number into an equation that also incorporates the time it takes to exit the car, hook it up to a recharging source, walk over to the toilet facility, urinate, walk back to the car, unhook the car from the charger and then drive off.

So does time to wee equate to time to charge? Curiously (at least for me), the “Law of Urination” states that mammals in general take 21 seconds to pee. So the actual act of urination is not the limiting factor here, rather accessing a place to urinate is the issue. For argument’s sake, I will assume that the toilet break is limited to 20 minutes since we need to walk to and from a toilet cubicle.

Next we need to know how long it takes to charge the Tesla. There are a lot of factors that come into play here including the starting charge of the battery, the desired ending charge of the battery and the quality of the charger. Given we are interested in the dynamics of a long road trip here, the driver is going to be using some kind of supercharger network. To get a sense of the charging experience at a Tesla Supercharger, check out the video here:

In the video, you can see a top charging rate of 100 kW, which translates into 375 miles added per hour. The theoretical top charging rate at a Tesla Supercharger is actually 115 kW, but as the battery gets close to being fully charged, the rate of charging drops off.

ChargingRateTeslaModel3

 

What can we deduce from all this? Well, if a long distance driver wants to do two back-to-back journeys of around 300 miles each at the top speed limit allowed in the USA and only needs one toilet break of 20 minutes, then the Model 3 can’t deliver that kind of range performance (but an ICE vehicle can). You currently need a good hour of charging in that scenario for your Model 3, even assuming access to the best possible charging rate at a Supercharger.

At this stage, you may point out that the vast majority of car journeys don’t include driving 600 miles straight in two back-to-back sessions with a 20 minute break in between. But that is not really the point. In an earlier post, I established the conditions needed for the auto market to tip between being ICE dominated and EV dominated. The condition was that an EV needed to match or exceed an ICE vehicle in every car attribute. So if an ICE vehicle is superior for long distance marathon driving, EV penetration will be slower.

Nonetheless, it is only the year 2018, and Tony Seba’s 95% EV penetration-rate target by 2030 is still 12 years away. Further, I think the EV is not that far away from matching an ICE for long-distance driving already for two reasons.

First, as the battery capacity gets bigger, the battery will still have a lot of juice when the driver reaches the first toilet stop. With a 50% bigger battery and a 450 mile initial range (achieved through charging overnight), 150 miles will be left in the battery at the first stop. So for leg number two of the journey, only half the charge time is required since we are only topping it up and not starting from zero. (Yes, we could talk about three back-to-back stages amounting to 900 miles, but the driver will eventually have to eat, and, as we get beyond the 99.9% percentile of typical journeys taken, I think we can view these as true outliers.)

Second, as each Supercharger generation is rolled out, the rate of charging will go up. Tesla has already flagged that the V3 Supercharger will arrive this summer and the rate of charge is likely to be between 200 kW and 250 kW, so a roadmap exists toward halving the best current charging time.

Beyond Tesla, two open standards exist that allow shared usage by vehicles produced by different auto makers. These are the CCS standard (backed by the CharIn consortium) and the CHAdeMO standard. CCS, promoted by the German auto makers amongst others, is working toward a charging rate of 350 kW as well as inductive wireless charging stations. The CHAdeMO consortium, which is principally composed of Japanese automakers and electric power companies, is aiming for a rate of 400 kW in the coming years. A good primer on fast-charging protocols can be founder here.

Both CCS and CHAdeMO are having to play catch-up with Tesla’s Supercharger network, which has just reached 10,000 sites worldwide. Undoubtedly, Tesla’s strategy of “build them and they will come” appears to be far superior to the opposition’s strategy of “we will build them when they ask for them”. You can check out Tesla’s global Supercharger network here.

TeslaSuperChargerNetwork

Summing up, while I think access to fast charging facilities will become a non-issue in a few years time, the need for batteries to get better with respect to specific energy and density is still a pressing need if EVs are going to unseat the current dominance of ICE vehicles. Further, to get the required improvement, do we need a John Goodenough-style leap in battery technology or will a Tesla-style incremental improvement in existing technology suffice? That will be the subject of my next post.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

 

 

 

 

Testing Tony Seba’s EV Predictions 15 (Three Nominations for Nobel Prizes)

About a 10 minute walk from my home in Oxford can be found the University of Oxford’s Inorganic Chemistry Laboratory. From my photo below, you can see that the building sports a series of blue plaques commemorating the laboratory’s greatest achievements.

IMG_1360

The bottom one reads as follows:

Here in 1980, John B. Goodenough with Yoichi Mizushima, Philip C. Jones and Philip J. Wiseman identified the cathode material that enabled the development of the rechargeable lithium-ion battery. The breakthrough ushered in the age of portable electronic devices.

Goodenough, now aged 95, is still actively researching battery technology to this day. An affectionate review of Goodenough’s extraordinary career by the journalist Steve LeVine can be found here and an article on a controversial new claim by Goodenough here.

What Goodenough and his team managed to do was create a battery cathode stable enough to act as a source of lithium ions without collapsing in upon itself. This allowed a battery to be charged and discharged, yet hold its energy in-between. The team did this through experimenting with a variety of metal oxides until they came across a lithium-cobalt-oxide combination that provided power with stability. To complement this great leap forward in the cathode, progress was required in the anode, and that came in the mid-1980s through the work of Akira Yoshino in Japan.

LithiumIon

Yoshino’s genius was to match graphite in the anode with Goodenough’s lithium-cobalt-oxide in the cathode. On top of the basic battery chemistry, Yoshino also pioneered a number of fabrication techniques that eventually took the lithium-ion battery out of the laboratory and into commercial production by the Sony Corporation. In short, the Goodenough-Yoshino insights produced a dramatic leap in deliverable power and energy storage.

Lithium-Ion Battery

Although the lithium-ion battery revolution of the 1980s ushered us into a world of ubiquitous mobile electronics, it was initially not sufficient to beget the transport and energy storage revolutions Tony Seba talks about in his presentations. Part of the problem here is that the battery makers face an optimisation problem with 6 variables. They need to look at all of the following:

  1. Safety and maturity on the battery cell level
  2. Power capability and charge/discharge characteristics
  3. Energy contents of the battery cell
  4. Cycling efficiency and self-discharge
  5. Degradation and aging phenomena
  6. Material and battery cell cost

The battery chemistry required is a perpetual trade off between these six. A push for power can compromise safety, and so on it goes. A second problem is that a battery is a multi-component mechanism. You have a cathode, an anode, an electrolyte and a separator. As you tweak the chemistry of one, it will have a tendency to produce unintended consequences in the chemistry of another.

LithiumIonBatterySchematic

Finally, and perhaps most importantly, a battery is not subject to Moore’s Law: it is subject to Faraday’s First Law of Electrolysis. This states that the amount of current passed through an electrode is directly proportional to the amount of material liberated from it. In other words, there is a linear relationship between electrical current and material. You may be able to increase the amount of material liberated from an electrode through using a different kind of material, but what you can’t do is increase the electrical current with the same amount of material.

 

This is a very different relationship from that referenced in Moore’s Law (which is really an empirical observation not a physical law). I blogged on this same topic three years ago (here) and at the time referred to the original 1965 article by Gordon Moore that ushered in Moore’s Law entitled  “Cramming more components onto integrated circuits.”  In the original paper, Moore referred to a doubling of the number of transistors on an integrated circuit board every year, which he later modified to every two years. Either way, the only way you can display that kind of growth on a graph is through using a logarithmic scale as can be seen with what actually happened:

Moore'sLaw

And let’s contrast and compare the Moore’s Law dynamic against battery advances (from here):

BatteryMooresLaw

Nonetheless, you can see that considerable progress has been made. Note that the progression from Goodenough’s lithium-cobalt-oxide combination to a nickel-magnesium-cobolt-oxide combination is an advancement of the same type of chemistry, not a new technological leap. Interestingly, Goodenough himself is rather dismissive of such incremental moves, feeling that they won’t be sufficient to supplant the internal combustion engine. From the Steve LeVine interview:

The stakes are high, and Goodenough dismisses a lot of the competing approaches he sees—Tesla’s Elon Musk, for instance, who he says is content to “sell his cars to rich people in Hollywood” while waiting for scientists to create a battery that will power a middle-class electric car. That is not precisely fair—Musk is obviously selling his $80,000 to $100,000 cars to an elite niche, but by 2018 he vows to have a roughly $35,000 model for a broader slice of the market. He is getting there through agile engineering that has provided incremental improvements to his battery.

But Goodenough is equally dismissive of such tinkering and its measly 7% or 8% a year in added efficiency. “You need something that will give you a little bit of a step,” he says, “not an increment.”

By chance, when I blogged about the state of batteries in March 2015, I came to a similar conclusion (even though I hadn’t read the LeVine article at the time):

Tony Seba, Ray Kurzweil and other assorted techno-cornucopians achieve almost instant doublings by assuming growth rates in the high teens or better. Unfortunately, much science progresses in the low to mid single digits, so change is measured in decades–not years.

The distinction is important. Under the Kurzweil logic, we don’t really need to tackle climate change or resource depletion because technology is on the case. Just go about your business as usual, tuck up your kids in bed at night, and scientific innovation will do the rest.

But unless Argonne Laboratory‘s battery guys and their peers step up the pace (which looks exceedingly difficult), electric vehicles will not replace conventional internal combustion engines for a couple of decades or more. That translates into no natural near-term carbon emission mitigation in the field of motor transport. And unless we get very lucky with climate sensitivity to CO2, that also means we will get a lot closer to exceedingly dangerous climate change.

It now appears that I (and Goodenough) could have been wrong: “such tinkering” has managed to deliver double-digit efficiency gains. These gains have, in turn, allowed Telsa to start tipping the market toward EVs at the luxury end with the Model S. And Elon Musk now appears to be doing the same with respect to more compact cars with the Model 3.

If Tesla keeps going into more and more segments (and drags the entire auto industry along with it), then through mitigating (but perhaps not eliminating) the risk of dangerous climate change, Musk, along with Goodenough and Yoshino, will have had more impact on the planet than any human being who has ever lived. We define the Anthropocene as the geological period over which human activity has had an appreciable impact on the environment and climate. Should Tony Seba’s transport and energy revolutions come to pass, it is extraordinary to think that the actions of Goodenough-Yoshino-Musk will have shaped how the Anthropocene unfolds.

I believe that Goodenough and Yoshino certainly deserve to be awarded the Nobel prize for chemistry. Further, should battery efficiency continue to progress at its current pace such that fossil fuels are removed from the transport and energy storage equation, then the role of all three in preventing dangerous climate change will have been immense. Indeed, I can’t think of any three more fitting recipients of the Nobel Peace Prize in such a situation.

Nonetheless, I have got a little ahead of myself in handing out Nobel prizes. While I am far more confident than three years ago that we are close to an EV tipping point, we are not quite there yet. So in my next post we need to dig still deeper into battery efficiency and cost to see whether battery technology can advance just that little bit further to push ICE technology to one side.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

Testing Tony Seba’s EV Predictions 14 (Deconstructing the Car)

In my last post, I set the conditions that determine whether the auto market tips from internal combustion engine (ICE) vehicles to electric vehicles (EVs). EVs need to either match or exceed ICE vehicles with respect to every car ‘attribute’ at an equivalent cost. Then it’s game over for ICE vehicles.

The attributes of a car give a consumer happiness. That utility comes from a) the mobility a car provides, b) the aesthetic of the car (the pleasure the owner gets in owning the car that is not related to other people) and c) status-signally through displaying ownership of the car to other people (such status signalling is not restricted to investment bankers and their Ferraris; it also covers hippies in their Citroen 2CVs and Green Party members in their Nissan Leafs).

The purchase decisions of consumers are based on their current budgets and future budgets. Current budgets determines how much they are able to pay for cars and future budgets determine how much they can afford to run their cars (fuel, maintenance, depreciation).

If EVs are better with respect to some of these aspects of the purchase decision but worse in others, then taking market share from ICE vehicles will be an uphill slog. That is what Exxon Mobile believes as illustrated in this chart from its latest “Outlook for Energy: 2018”:

ExxonMobileEV Forecast

If such a projection is correct, around 50 million EVs will be on the road (which includes pure battery and plug-in hybrids) in 2030. That compares with the Tony Seba S curve view of 130 million EV sales alone in that year.

To tease out who is likely to be right, let us think of the physical limits auto makers have to work with. Basically, a car is a three dimensional irregular cuboid shape constrained by such external factors as lane width and parking space size. Certain things are then put into this irregular cuboid shape to provide the mobility, aesthetic and status-signalling attributes we identified before.

Lots of car ‘stuff’ is not a function of whether it is an ICE vehicle or EV. For example, the headlights, wing mirrors, windscreen wipers and so on. We can exclude such items from our analysis since an EV can match the ICE vehicle in these domains. Moreover, there is no reason why an EV can’t match an ICE in terms of aesthetic or status-signalling should its design be good enough and its ability to fulfil the mobility criteria.

The main differentiator between an EV and ICE vehicle when it comes to mobility relates to the drivetrain. Taken, holistically, we can think of this as encompassing a store of energy and a means of converting that energy into motion. We can now compare EVs against ICE vehicles in respect of this broadly defined drivetrain across a series of factors, most importantly:

  • Weight
  • Volume
  • Efficiency
  • Flexibility

Given its position as the undoubted pacesetter in cutting edge EV design, performance and production numbers, Tesla’s Model 3 is a worthy champion for the EV camp. The standard Model 3 has a curb weight of 1,610 kg, while the extended range version is 1,730 kg. The crotchety Jack Rickard did a tear down of a wrecked extended-range Tesla Model 3 (warning: it is a long video) and extracted the battery, which weighed 478 kg. So that means the battery weighs roughly 28% of the car.

Let’s choose the BMW 330i Sedan as a typical ICE competitor for Tesla; its specifications taken from BMW’s USA site can be found here. This sedan comes in at 1,610 kg, so the Tesla is 7.5% heavier. Curb weight generally includes a full tank of fuel, which in the BMW’s case is 15.8 gallons or about 45 kg in weight (you can see here the extraordinary energy density of fossil fuels).

So that in a nutshell is the handicap of the battery as an energy source: more than 400 kg of extra weight. On the other side of the ledger is the fact that you wonder where the engine has gone in an EV. Here is the schematic for the Model 3:

Model3Schematic

First, you notice the radical shrinkage of the actual engine itself. An internal combustion engine is a system of controlled explosions that first translate into lateral movement of the pistons, which in turn has to be translated into circular movement to the wheels. That requires a complex multipart machine.

The video below compares and contrasts the Tesla drivetrain with a traditional ICE (but note it highlights the induction motor in the Model S; the Model 3 motor and electrical motors in other automakers EVs are somewhat different) and emphasises the fact that the electrical engine has radically fewer parts.

And here is a couple of minutes on the Model S engine showing its intrinsic simplicity:

The key differentiator, obviously, is the disappearance of a bunch of ICE components: transmission, exhaust system, fuel pump, fuel injection and spark plugs. An EV does need some kind of cooling system for both the motor and the battery, but this is relatively modest in both weight and volume.

Overall, if we take out the gas tank and the battery from the equation then we get this:

EV drivetrain weight <  ICE drivetrain weight

EV drivetrain volume < ICE drivetrain volume

But through adding the battery and gas tank back in, these inequalities reverse:

EV drivetrain weight >  ICE drivetrain weight

EV drivetrain volume > ICE drivetrain volume

Now, it’s very difficult to put numbers into these inequalities. But the interesting thing about Tesla’s Model 3 is that it incorporates a large battery in terms of kilowatt hours (kWh) but the car is still in the same ball park weight category as its ICE competitors. Moreover, we are currently going through a period of rapid battery cell shrinkage (weight and volume per kWh). Let’s say Tesla can shrink the 479kg battery that Jack Rickard extracted from the wrecked Model 3 by 25%; that would give a weight saving of 120kg. We are now getting into matching territory. And remember the conditions for tipping. EVs don’t need to exceed ICE vehicles for the market to tip: they just need to match in most areas and excel in a few.

Next we come to flexibility, which really relates to the configuration in our irregular cuboid. So yet again putting the battery to one side, the EV has an instant advantage. The drivetrain units can be arranged more flexibly as they are linked principally by wires, not by a complex transmission mechanism.

Even with the battery, the possibilities of dividing it up and distributing it around the car have yet to be explored. Safety and cooling issues not withstanding, the overall battery is cellular and is just composed of thousands of small batteries. We talk of form factors with mobile phones, and this is ultimately where we will move with cars. With an ICE, you have to design around the drivetrain, with an EV the drivetrain can become subservient to the design.

So then we move to efficiency, with respect to which the EV wins hands down. An electrical motor can deliver instant power and torque. In the US context with imperial units we have this equation.

PowerEquation

Which translates into this chart:

TorqueRPM

As a result of the dynamic in the above chart, Tesla is currently able to deliver supercar type performance at a fraction of the cost of the likes of Porsche, Bugatti or Ferrari (source: here). Note that Tesla’s new Roadster due to be released in 2020 will have a base model that delivers zero to 60 in 1.9 seconds; that will be the first production car ever to break two seconds.

CarAcceleration

Moreover, such high-end, halo EV performance profiles will trickle down. Ultimately, taking price to price comparisons, the EV will leave the ICE car in the dust when the stop light turns green. For those of a non-macho disposition, you may not care. But to repeat (again) if the EV is equal on all metrics but ahead on just one that you care about (all at an equivalent price), then you will buy the EV.

And yes we still have the constraint of range and price. And yet again this takes us back to the battery. Indeed, the EV battery is like the little Dutch boy Hans Brinker whose finger in the dyke is the only thing stopping the entire neighbourhood being flooded and his family and friends being drowned. But once the battery gets down to a price and efficiency point not far from now, that dike will go and the ICE industry with it. The battery is the subject of my next post.

HansBrinker

For those of you coming to this series of posts midway, here is a link to the beginning of the series.

 

 

 

 

 

Testing Tony Seba’s EV Predictions 13 (What Makes Us Buy a Car?)

“What makes us buy a car?” Well something obviously does since global sales of cars and light vehicles reached around 100 million a year in 2017. Moreover, if we can answer that first question then we are in a better position to answer this question: “What makes us choose an electric vehicle rather than an internal combustion engine (ICE) vehicle?”.

These questions come from the demand side. Up to now, all my posts have basically been dealing with the supply side. That is asking questions such as “Who will sell EVs?, “Who is  investing in EV production?”, “Will there be enough lithium?”. My answers to those types of question leads me to believe that the supply side can keep us on Tony Seba’s EV penetration S-Curve through to at least the mid-2020s. But will anyone buy these EVs even if the auto makers build them?

Hoping to shed some light on that question, I have been toiling over reports by companies and organisations that forecast how many vehicles will be sold in the future and what percentage of those vehicles will be EVs. In September 2017, David Roberts at Vox wrote a nice piece pulling all those forecasts together:

VoxEVForecasts

A reminder: I have taken Tony Seba’s death of ICE vehicles by 2030 forecast to mean 95% market penetration (130 million EV sales). From the middle chart above we can see what everybody else thinks:

  • Exxon Mobil:   10% by 2040
  • British Petroleum:   10% by 2023
  • Norway’s Statoil:   40% by 2040
  • Goldman Sachs:  9% by 2040
  • OPEC:   12% by 2040
  • Total SA:   22% by 2030
  • Bloomberg New Energy Finance (BNEF):  55% by 2030

So they don’t agree with Tony. But my interest with them is less in the forecasts themselves (a topic for a future post), but rather how they were arrived at. Keep in mind that what I did in the chart below is not make a forecast but rather fit a few data points into a logistic function to produce an S curve:

Seba Central Scenario

To repeat, this is a data fitting exercise. I’ve just taken Tony Seba’s point forecast of 95% penetration by 2030, the current penetration and sales of EVs, and added an S curve that looks reasonably sensible. But it is not a true forecast.

There are a couple of ways to forecast: 1) you can create a model which is purely empirical and takes an historical time series and then projects it forward, or 2) you can build a microeconomic model in which your forecast variable is a function of variety of other variables. Hoping to learn what methods and methodologies these esteemed organisations and companies have been using to arrive at their EV penetration rates, I trawled through the back pages of their reports looking for references and helpful appendices, but there were none to be found (at least as far as I could find; I am still working my way through these reports).

I get the distinct impression that the forecasts drop down like manna from heaven. It’s basically a game of pick a number that looks roughly right based on your organisation’s attitude toward EVs and then construct a vague argument surrounding that forecast number. You could argue, perhaps, that it is impossible to do anything more rigorous given the profusion of variables that come into the purchase decision, stretching from GDP growth rates and the oil price at the macro level to eco fashion and periodic EV safety scares at the micro level. But I still think we can do better than that, by adopting a somewhat different approach.

From the existing academic literature based around ICE purchase decisions, we know that consumers have a fixed budget and are presented with a basket of goods that they can spend the budget on (or save). You can consider that basket of goods as consisting of cars and non-car goods. A consumer will buy a car rather than the alternative of non-car goods if the car gives him or her a higher degree of utility (happiness or pleasure). The sources of utility derived from a car can be thought of as threefold:

  • Mobility
  • Aesthetic
  • Status signalling

So cars aren’t just a means of transport: they are also like large pieces of jewellery which give one pleasure through personal contemplation of them and through displaying them to other people.

Finally, the budget constraint is temporal: it stretches from the present to the future. So the purchase decision is not just bounded by the current available budget but also budgets through time. Accordingly, the purchase decision takes into account future costs captured by

  • Fuel
  • Maintenance
  • Depreciation and replacement

This is all pretty much common sense even if I have used economic terms, which may be unfamiliar for some. But I hope we can pull out some insights that will impact on EV adoption rates. The next bit is important: I don’t have to build a complicated multivariable model and input millions of data points into a computer to derive some insights. From basic theory, I know how the model will act in certain conditions. Let’s look at one such set of conditions.

First, we start with a budget constraint existing now in an ICE dominated world. Consumers have allotted to spend an amount of money now and in the future on a means of mobility whether EVs exist or not. This is where it gets interesting and why I feel the adoption forecasts by the likes of Exxon Mobile and the International Energy Agency make no sense whatsoever.

If any individual consumer is faced with an EV that is a) cheaper than an ICE, b) has lower ongoing costs than the ICE, c) has better mobility characteristics than the ICE, d) is prettier than the ICE and e) signals status better than the ICE, then that consumer will always choose the EV. That is because the consumer will get a higher level of utility from the EV purchase. (Alternatively, the consumer will spend less money buying an EV yet get the same amount of utility as buying the ICE, so then having extra money to spend on non-car goods.)

In fact, I can even relax these conditions a bit. Let all the factors be equal except one where the EV is better. That market will also flip 100% EV too. Don’t believe a market can do that? Look what happened with film and digital cameras.

I admit to some brakes on the transition: the consumer has to be aware of how the variables have changed in EV’s favour. That requires active information searches or exposure to information through advertising and marketing. The psychology and marketing literature covers that aspect of decision-making well.

ConsumerDecisonMakingProcess

Moreover, a more important reason why markets don’t flip overnight (ignoring the supply side) is because they go through an intermediate phase where some of the factors differentiating between products are positive and some negative. And given that consumers derive different utilities from each factor, the market will move in phases from one state to another as each individual faces a different decision-making process.

For example, purchasers of the first Tesla model S were deriving most of their utility through signalling that they a) were an early adopter of new technology and so were hip, b) had superior eco credentials and c) had immense wealth since they could afford the car. The rest of the population didn’t have the budget to buy the car and/or was less interested in the status signalling or, maybe, just didn’t like the look of the car. So the market didn’t tip the first day the Model S went on sale.

This brings me to why I think consensus forecasts for EV penetration are barking mad. As of 2018, EVs have already exceeded ICE vehicles with respect to a number of the variables. They pose less of a future budget constraint because they a) are cheaper to run, b) have lower maintenance costs and c) have a longer potential road life as they have fewer parts to wear out.

So we are left with the upfront price of an EV versus an ICE (which is the current budget constraint), the mobility functions, aesthetic and status signalling.

For EVs, nearly all of these factors relate to the size and cost of the battery pack. If the battery pack price can come down enough, the drive mechanism of an EV will be cheaper than an ICE, which means the overall vehicle will be cheaper. Note that engine power delivered by a battery is already better for an EV than an ICE. If the energy density of batteries improves enough, then the mobility characteristics such as range of the EV will be able to at least match the ICE. If the battery pack shrinks enough, this will improve mobility characteristics such a storage and opens up a range of new form factor possibilities that impact aesthetics.

There is one aspect of the aesthetic that I think an EV can’t match; that is, the joy brought to some people through owning a piece of precision engineering. A high end ICE is a marvel of engineering and an ICE engine has an aesthetic all of its own. The residual ICE market for me will be cars as luxury watches. Rolex, Tag Heuer, IWC, Breitling and Breguet of Switzerland still sell mechanical time pieces, but their market share is tiny. That to me is the fate of the ICE due to the cold, hard logic of the EV surpassing the ICE on  every other variable that goes into a consumer decision-making process.

So the battery holds the key. That will be the subject of a future post.

For those of you coming to this series of posts midway, here is a link to the beginning of the series.