That Prius v 12V battery doesn't look like it is designed to last 10+ year (looking at the size of it). Since I'm in Alberta and sometimes the winter can be a bit nippy, I plan to run run extension cord inside through one of the plugs in the battery compartment and plug it nightly to trickle charge the battery. Only time will tell how long the battery will last. The "Extreme charger" I just connected to the battery it is using "pulse charging" to maintain the voltage @ 13.3V The car will be driven sometime only 5-10km a day so it might not be enough to recharge the battery by ICE. It seems to me that battery is powering a lot of accessories + my wife likes to listen to the radio whenever she has a chance (ICE running or not) such a small battery might not last long without extra help :-/ The other day I've seen small Honda (new one) lady couldn't start the car, it turns out she drained the battery by waiting at the school and listening to the radio for over 30min. (in winter time).