more questions - charging in rain? topping off? saving EV?

A Tesla fast charge still takes over an hour, and none of these cars has one battery, it’s a bank of many, many batteries. So maybe an individual battery isn’t being charged much faster than a Prius charges an individual battery.

 

You're replying to a post from 2012

 

Your Prius has two batteries - the 12V battery, and the HV traction batteries. The traction battery contains many blocks, which contain many cells. Not many batteries.

Your typical AA "battery" is really a single cell, and calling it a "battery" is a bit of a misnomer, as technically it needs to be multiple cells to be a "battery".

 

What-ever

 

I don't believe there is evidence that topping off the battery reduces its lifespan or efficiency. You don't get either fully charged battery when the indicator says 100%, nor completely empty battery @ 0% - I believe the safety margin is around 20% on both ends.

I don't know about the Prius, but the Bolt manual tells you to keep the car plugged in very cold weather, and I don't recall it recommending not to keep it plugged in any context.

Regarding charging in bad weather: if in doubt, the best thing would be is to ask the manufacturer the same question.