Remaining battery life
This is a very critical factor one should take into consideration while buying a used EV. The used EVs with good condition of the battery is a common thing. But, you should still check the remaining battery life and range before spending the money, just like you check before buying a used ICE vehicle. After all, it is about value for money.
It is difficult to define the battery life and range, but there is no harm in trying to learn that. There are some startups in the market that offer these types of solutions. Also, keep in mind that battery life depends on factors such as charging type, charging frequency and to what level the battery was drained out.
Fast charging might lower the downtime for the EV, but it fries the battery. A slow but regular home charging socket ensures a longer battery life. Draining out the battery to zero and charging it frequent also impacts the battery life negatively. Inspect these factors before you buy the used EV.