12V battery maintenance for dummies when gone for weeks

I realize you are trying to be helpful but what explains 1 replacement battery in 10 years on my gen4 Prius using it in a rotation with my other 2 vehicles?

 

I know how the Gen 4/Gen 5 Prius BMS works, as I studied it with a battery monitor. You don't know the current SOC of your battery. At least, get a BM2 battery monitor and find out. I bet it is below 50%. Just because you have escaped so far from a dead battery doesn’t mean it will never happen.

Other battery maintainers might work. I hope what you have is a smart battery maintainer and not a dumb trickle charger as you think, since the latter can damage the battery.

 

I have 3 of those, lol. 1.25 amp model. I think they're good. They might be the original 'battery maintainer', not sure. Gotta be careful about throwing the term 'trickle charger' in these parts, lol.

 

Just out of curiosity where do you attach the battery maintainer? The battery itself or under the hood at the jump terminals?

 

I put a NOCO permanently next to the battery, under the cover. I haven't used it yet. I got one suitable for under hood mounting in case I went that way.

 

Also, attach a BM2 battery monitor to the battery.

BM2 battery monitor