We're slightly off target here. I should have made it clear that the Honda is a mild hybrid ie no external charging. The small EV battery is more about a boost of power occasionally and helping the ICE economy. We arent ( yet) looking at a full BEV as much as anything because of the silly purchase costs.

My concern was with the life of the small Li Ion battery in the Honda. How long will it last - the driver has no control over how it is used so the life should be fairly predictable. And given that we both are in our late 70s, how many driving years will we have to cover anyway?