Long term viability of eBikes?

[peterb]

Best place for them.

[Airsporter1st]

I would think it might start to be a problem when bikes are 15-20 years old, but I suspect some sort of bodge would be possible. How many of these bikes will still be in use then?
Inherited a high quality Cordless drill, with NiCad batteries. Batteries are knackered and can't get replacements, so drill will go for recycling, a shame but it is probably 30years old!

Not too difficult to get Nimh as diy replacements for the NiCads and generally the same charger can be used and the batteries suffer less memory effect and are far more tolerant of sporadic use.