Probably more than a "few" I think that you will be looking at 5-7 for the cars to fall to under a third of new value. Although that depends on your definition of "a few"* I guess.
* https://www.grammarphobia.com/blog/2010/05/how-much-is-a-few...
* https://www.grammarphobia.com/blog/2010/05/how-much-is-a-few...
* https://fullycharged.show/blog/surprisingly-positive-news-on...
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
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.
Also EV's tend to have rebates and tax write offs that reduce their actual purchase price significantly. Which probably also depresses resale prices.