Which end of the segment? Cells don't degrade uniformly, so refurbishing the existing battery is gonna be a couple hundred bucks to tear the car down and expose the battery, and then identity the bad cell and pop in a new one. At the other end of the segment, a battery for a Tesla that has more range than when it was new is gonna run you more than a couple grand. Depending on the heat it was exposed to, and number of cycles and really the age of the vehicle, it change when you'll have to replace the battery. It's worth pointing out that batteries do need to get replaced at some point, but also who knows if the used ICE car you're buying is gonna have problems passing smog, or if the cooling system's gonna crap out on you 3 miles after you drive it off the used car lot.

Worth noting that just replacing cells on an old battery pack is kind of iffy. If the new cell has a different capacity and/or internal resistance than the old cells, it might not balance properly. Probably not an issue if it's within the range of what the BMS can deal with, but there is some risk that swapping cells might cause problems.

Having said that, I don't have first-hand experience refurbishing EV battery packs. Someone who does this kind of repair regularly might have a better idea of what you can or can't get away with.

> Cells don't degrade uniformly, so refurbishing the existing battery is gonna be a couple hundred bucks to tear the car down and expose the battery, and then identity the bad cell and pop in a new one

This sounds great, for which EVs is this available?

"For many electric vehicles, there is no way to repair or assess even slightly damaged battery packs after accidents [..] Battery packs can cost tens of thousands of dollars and represent up to 50% of an EV's price tag, often making it uneconomical to replace them.

While some automakers like Ford Motor Co (F.N) and General Motors Co (GM.N) said they have made battery packs easier to repair, Tesla Inc (TSLA.O) has taken the opposite tack with its Texas-built Model Y, whose new structural battery pack has been described by experts as having 'zero repairability.'"[0]

https://www.reuters.com/business/autos-transportation/scratc...

That take is ridiculous.

The cost to replace a Model Y battery is around $13K (no where near 50% of the cost of the vehicle). More than that, the battery will probably outlast the lifetime of the vehicle, with a design lifespan of approximately 500K miles.

Yes, eventually when the battery dies it won't be repaired as such - instead it is designed to be nearly 100% recyclable.

Here's the (long) story of a Tesla Model S battery repair job for $5k, far shy of a quoted $22.5k that Tesla wanted.

https://www.youtube.com/watch?v=T7Q0nNkQTCo

Here's where right to repair is exceedingly important. Obviously if it were up to Tesla, you'd only be allowed to go to them for repairs, at their full markup. But here's the secret - they have a huge markup, but no monopoly on electrical engineering. Like the video shows, 3rd party repair shops can repair these things. It's not rocket science - you're thinking of a Elon Musk's other company, SpaceX.

But $5,000, down from $22,500, is still more than "a couple hundred bucks to hundred bucks to tear the car down and expose the battery, and then identity the bad cell and pop in a new one". Now, in my haste, I wrote "cell" when I mean "module", sorry about that. The car for which I'm referring to that job is at the bottom of the segment - a first generation Nissan Leaf. They first came out in 2010 and here's a 12 year old used one for $6k (https://losangeles.craigslist.org/wst/ctd/d/redondo-beach-20...). It's almost guaranteed to have at least one bad module if you're buying something that particular car (they didn't have battery cooling systems that generation) and that old (simply due to the number of charge cycles).

The procedure for finding the and replacing the bad module is documented at:

https://www.youtube.com/watch?v=FTiFEapky8s&t=24s

and

https://www.youtube.com/watch?v=TVaCMbXKrd4&t=423s

For the module itself, you're looking at 3rd party supplier for a refurbished one. Here's one battery module for $90 on Ebay https://www.ebay.com/itm/354422211418?hash=item528535c35a:g:...

or another listing asking $250: https://www.ebay.com/itm/225422969988?hash=item347c418c84:g:...

Or via FB Marketplace for $60: https://www.facebook.com/marketplace/item/5165480583467846/

If you take your Nissan Leaf to a shop that specializes in them, they'll likely have modules for cheap off salvaged cars, but we don't have access to those prices here. So let's say a refurbished battery module is anywhere from $60-250 and then kick $200 in labor to your cousin who's good with cars to watch those two videos and replace the bad module for you unless you're that cousin, then spend $250 on a battery module and buy yourself a nice voltmeter.

Official battery replacement jobs on a Nissan Leaf are going to run you much more (multiple thousands) but if you have a Nissan Leaf, or any electric car really, you should be aware that that's a total ripoff. Everyone knows you don't go to the dealer for repairs on an ICE unless you want to get ripped off, and the same is true for EVs.

If you actually follow what happened to Hoovie, that $5k job didn't work. He used that vehicle on one of their 'Car Trek' series and it had BMS errors and basically threw a fit because the batteries were unbalanced. Tesla is right to want the entire pack to be replaced, because having cells with two very different aging characteristics is bad for the battery overall.

Obviously there's some batteries that are tolerant of this (Prius' commonly have this repair on their NiMH batteries), but it's not universal.

Here's a factory in the US that refurbs batteries for basically all brands but Tesla:

https://youtu.be/HIurjZsWJoc

Similar to many Apple or Xbox repairs, they swap it for one they've previously refurbed and tested, then add yours to the pile to be refurbed for another customer rather than make you wait for your specific battery to go through the process.

Similar to a new engine, with a similar lifespan expectation.

The engine on my car is 20 years old, and still pretty fine. Will an EV battery last as long (say 160K miles)?

Not trying to be adversarial - genuinely curious. I only buy old cars (median is 8 years old), and I keep them for a while (5-10 years), and I often wonder whether EV cars that old would be a decent buy or not.

As I posted above, batteries typically last 1,000 to 2,000 cycles, which gives most EVs between 200,000 and 600,000 miles of battery life -- and at the end (barring going out with some sort of fault) you can still manage 70-80% of the original charge.

We don't really know for current EVs how calendar aging will affect them, but we can look at older EVs with now-obsolete batteries. Some of them are fine, some of them aren't. Chevy famously did a recall on their Bolt battery packs, and a lot of Nissan Leaves had their batteries go bad. The problem with the Nissan Leaf is they only had passive cooling on the battery. So, lesson learned. Basically everyone does active cooling now.

In theory, lithium iron phosphate batteries should last a very long time. That's what I'd go for if you want the best longevity, but they also have a lower energy density and can be damaged if you charge them in below-freezing temperatures. (Presumably all the cars with LFP have smart charging systems that disable regen and refuse to charge when the battery is too cold, and hopefully most of them have battery heaters.)

With batteries there's this weird dynamic that if it last for a reasonably long time, by the time you need a replacement the new batteries /should/ be much cheaper and more energy dense. Unfortunately, there aren't really any companies making 3rd party aftermarket batteries for old cars. Maybe that will change, and maybe the industry will standardize on some generic battery module design. For now, the replacement battery options seem to be a) buy a replacement from the OEM, b) find a replacement from a low-mileage junkyard vehicle or c) reverse engineer the BMS and install an equivalent custom battery constructed from new or used cells/modules, possibly using some kind of custom-fabricated battery box. It'd be great if you could just walk in to any auto parts store and buy a replacement battery pack, but we're not there yet.

Batteries last anywhere from 1000 to 2000 charge cycles, which for most EVs is 200,000 to 600,000 miles. And at the end of that you might expect the battery to hold 70-80 of its original charge, so even then it's not necessarily a write-off.

At 100% capacity I already have range anxiety, I don't think I'll be happy with 70%.

Couple hundred miles usually