EV Battery Longevity Needs To Meet A Minimum Standard For Consumer Confidence

I recently read this article about an out of warranty EV battery failure at 170,000 km (105,633 miles) and realized that premature battery failure has the potential to become a serious issue that impedes EV adoption in the future because there are various battery formulations (some not as long lived as others) or customers will pile on kilometers very quickly (a small fraction of drivers are very high mileage drivers). Also, customers will not always know or follow the best practices to maximize battery life. And finally manufacturers don’t always design their cars to take care of the batteries (the non-liquid cooled Nissan Leaf being a glaring example).

Right now EV adoption is not the issue, as demand has never been stronger (EVs are supply constrained, not demand constrained) and the high gas prices of 2022 has supercharged the demands of consumers for more EVs, but if the batteries start failing prematurely in large numbers it will negatively affect consumer sentiment in the future. The last thing we need is to get to 25-50% of new vehicles being sold being EVs and then a high failure rate starts giving new potential customers cold feet. Or worse yet, being weaponized by the political right to prevent future ICE market share erosion.

This is a big potential issue that we can’t simply dismiss as being one-offs.

Consumers need to have confidence they are buying a vehicle with a long battery life. Perhaps the best way to accomplish this is for EV batteries to have a 15 year/250,000 km (155,000 mile) warranty. By government mandate. To 70% capacity seems reasonable as batteries typically age by losing capacity instead of outright failing. As this is a reasonable lifetime for a gasoline vehicle, it’s a reasonable minimum to expect from an EV for long term consumer acceptance.

Right now, battery replacement is extra expensive due to inflation, but also because manufacturers have a monopoly on prices. Wholesale lithium batteries are likely in the neighborhood of $200/kWh at the moment (thanks to inflation), meaning a 50kWh battery should cost in the neigborhood of $10,000 (wholesale). However they cost a lot more than this due to OEM markup as the $20,000 in the linked article mentions. Also, there is virtually no 3rd party competition and batteries are a specialized product and it is hard to trust an aftermarket one to be as durable as OEM, yet it would still be many thousands of dollars if it were available.

In the future, battery prices will keep dropping, as prices drop under $100/kWh the prices should halve if the margins are kept low by OEMs. A big if, as most packs being made are earmarked for new vehicle production and not for failed battery replacements.

There are several options available to mitigate this problem in the future, for example offering used batteries, which will start becoming more plentiful.

Salvaging batteries from crashed/written-off cars is another possible source, though there would be potential liability issues to be sorted out.

Perhaps offering some type of prorated replacement battery cost would be helpful since few would want (or be able) to spend well over $10,000 on a 10- to 20-year-old vehicle (average vehicle lifetime is about 15-18 years).

Governments can also use laws to mandate EV battery replacement prices at a specified margin, say 10% above pack cost, in order to dilute the monopoly automaker pricing.

Battery packs need to be designed to be repairable. Depending on pack design, if one or a few cells dies prematurely it can brick the entire battery pack, leaving the EV owner with an inoperable vehicle. That said, being able to bypass or replace the errant cells is a liability issue in itself, so this needs to be navigated carefully, but it’s not an insurmountable problem.

Finally an obliquely related point — all EVs should be mandated to have battery health reports, from number of cycles, time spent at full charge/number of full charges, number of (super)charges and so forth. If it can be done for low cost power stations then it can be done for much higher priced EVs. This would give used EV buyers a snapshot of the health of the car they are considering.

So in conclusion, this is a big potential ticking time-bomb, but it’s not one that cannot be solved if automakers think ahead and if governments take this seriously and legislate reasonable minimum durability. Done correctly, stories like the one that inspired this article don’t have to happen in the future.