I’ve rebuilt ev batteries before, I do all my own automotive work and repairs, I’ve kept close eyes on the emerging battery tech for vehicles and know the battery chemistry used in current and older EV’s and own stocks in two different battery companies (any idiot can own stock, but I just mention it to say I have money on the line in paying attention to batteries. I keep a fairly tight portfolio). I’ve been working on electronics for 30 years and vehicles for over 20 years.

I’m not outstanding or anything, but that still puts me in a pretty narrow demographic on Lemmy, and evs are a subject of interest to me, while my job grants me a lot of free time to do what I want, which is often reading about things.

So the deal with the batteries: there’s been a handful of different types of ev batteries used over the past 15 years. Some lithium iron phosphate, some nickel metal hydride, some lithium, or nickel Cobalt aluminum.

Each has some positives and negatives but the overreaching delima with any of these is that they all need a lot of small individual cells to make up the entire battery pack (teslas can have 2,800 batteries all tied together to make their battery pack, for instance) and they all suffer from being charged/discharged. At current, lithium based batteries (most all of the newer EV’s) can last about 1500 full charge/discharge cycles before failure. But every single charge/discharge cycle does a small amount of damage in the formation of what is called dendrites. Dendrites rob a battery of capacity and eventually will short out the battery cell, making it go completely bad.

The damage to the batteries is worse at times of full charge and full discharge. And is lessened if kept in between. EVs use this to their advantage and will cut your vehicles power off showing 0%, even though there’s capacity left in the batteries to go several more miles, and “100% fully charged” when plugged in, will actually be only around 90% of the batteries max capacity. If you owned an EV and kept it between about 30% and 80% the entire time, and avoided fast charging, which also makes batteries go bad faster, your battery should last longer than most anyone else’s.

But anyhow, every battery used in an electric only vehicle today is 100% fact going to lose a bit of max range with every single charge, because every single charge causes a slight amount of build-up/damage to the batteries inside. Aside from that, no manufacturing process for those batteries is perfect, so not all of those hundreds or thousands of battery cells that make up the ev battery are perfectly the same, so they won’t all start to go bad a once. Once enough of those cells go completely bad (today’s evs track the cells and can compensate for the bad ones for a while) your battery, all 1,200 to 2,000 pounds of it will need to be replaced, and replacing them with a used/refurbished battery pack is a temporary bandaid after paying a large labor cost, or a new battery pack which will cost you more than what you would expect to pay for an entire 10 year old used car.

Manufacturers (and real world info as all electric evs are starting to get pretty old) expect the batteries to last 10 to 20 years. It’s looking like that’s a pretty good estimate. 20 years being a stretch, but doable for someone who slow charges at home , only charges to 80%, and doesn’t take trips that take them down too low on charge.

To give you an idea of how well auto manufacturers are aware of this, just look at a Ford mustang mach e. The most popular ev after tesla. They have a 8 year or 100,000 mile warranty on the battery. The mach e has a claimed range of 290 miles. Their warranty doesn’t take effect unless the battery capacity is less than 70% of what it was when new. Imagine having a car you paid $50,000 for, expected to get 290 miles with, and then 4 years later with 95,000 miles on it you can only go 210 miles and ford tells you to go kick rocks. Currently, that battery pack is about $23,000 dollars(most batteries arent this stupid high). Plus install. I just got rid of a mini van that was supposed to get 22 mpg. It was 16 years old, had 245,000 miles on it, and it still got 22 mpg. It was also still worth something. How much will a 16 year old EV that needs a $12,000 battery to work again be worth? Pretty much nothing after people learn how expensive and how guaranteed it is that they’ll need to have a new battery. I wouldn’t spend $12,000 on most 15 year old vehicles that are in great condition. The thought of paying to get a 15 year old vehicles that would still need a battery put in it is asinine.