Conventional wisdom seems to be that at best electric cars will depreciate at the same rate as ICEs or at worst their values will fall off a cliff, the reality is very different, at least in the short run * obviously this will change as production of newer cars ramps up.

* https://fullycharged.show/blog/surprisingly-positive-news-on...

The thing I'm curious about is how they will age

I would guess the mechanical components, motors etc will potentially be more reliable than ICE

But I worry about the batteries, if my laptop is anything to go by it seems like they will eventually die and will be expensive to replace

Today's ICEs are very reliable and generally outlast the car body - assuming your follow the maintenance schedule. All the wear on the body will be the same: pot holes, salt, accidents... Motors won't have nearly as much maintenance (you still need to lube bearings), but the car will die based not on the method of motor power in most cases even if you don't do the maintenance.

Batteries are a worry. Price has come down, but used electric cars are very cheap compared to the ICE cars because of this very reason. Until the market figures out how to replace the batteries at scale, and then buyers figure out how to account for the battery this will not change.