Gen 2 **12 volt** battery olympics

I think the kilometres driven is the best measure of how much we saved the planet (or at least damaged it more slowly), or how much fuel we saved. I remember gassavers dot org (first incantation) greatly, including the guy with the Ford who was fearless with mpgs, and also the AeroCivic (one of us here should do that with our Prius).

However the 12v battery doesn’t get much love. So : the number of kilometres driven, or maybe the number of years lasted, could be used to judge the effectiveness of the 12volt battery.

For a start, 2008 Prius Gen2 4-button spec, New Zealand. Main battery original; 12 volt battery - also original. 2-3 years ago it gave me grief with red triangles and occasional jump starts, and below 10 volts, but now it has fixed itself and never gives a triangle or any grief, for the last 18 months.

 

Also the hybrid battery is most important; if you can access cheap second-hand batteries and drive your car (and accept it can break down without affecting your job / employment), then experiment rebuilding the high voltage battery (plz avoid electrical shocks!);

However these are better than Toyota Gen2 batteries - https://priuschat.com/threads/prius-battery-replacement-genii-like-youve-never-seen-new-cylindrical-cells.181277/add-reply

I haven’t been asked to post this, but these are my ‘dream cells’ for my NiMH Priuses

 

I have a set of jump leads and a little 12v motorcycle battery in the boot for such eventualities; I agree it is way past it’s prime; it used to be at 10.x volts resting - but is more like 11 now!

I’m also using my original battery pack that had a sense cable connector fire; new voltage sense harness and ECU, but I didn’t clean the bus bars or anything - that was a few years ago, and still going strong!

 

Also for what it is worth, I left a 12v battery in my 2003 Prius Gen 1 in a garage, parked up for over a year; I didn’t unplug the battery. It was a challenge because my smart charger didn’t want anything to do with a 12v lead acid battery that was down to 0.3 volts; but I charged it up with some tricks; and it is holding charge even under a load test, which I found fairly impressive