strangenuts wrote:In regards to batteries under the bonnet and the temperatures they live in, the main battery being right up the front of the engine bay, it would be the coolest location and then it's performance less affected than an aux in the rear corner would it not?
Yep, you'd be right. My aux battery cops a LOT of heat that my starter doesn't. Just a compromise i've had to make because I didn't want it anywhere else. Am currently toying with some heat shielding actually ... just for good measure.
I did have to replace my original AUX battery (115ah wet lead acid) , primarily as it had crap caps on it that resulted in a lot of leakage (especially with rough 4wd'ing), i neglected it and hadnt checked water levels, then found it half-dry ... which means I neglected to keep an eye on the levels and it died due to my neglect. I think heat would contribute to it.
So now I have a maint free 105ah (some form of calcium lead acid) all-rounder ... I'll see how this goes over the next year.
Any battery that's subjected to a LOT of use (i do a LOT of discharging and re-charging, and trips away every 2nd weekend, up and down hot beaches at low speeds, running fridges, stereos, 2 amplifiers, and camp lighting through the night, and charging the next day = a lot of battery stress) ... is going to have a shortened life.
That said, my own auto sparky, and most of my mates have them in engine bay. One mate has it in his canopy under a false floor.
I didnt want my battery in my sleeping area, and I have a tub so there wasn't really any other suitable location.
If I start killing batteries, I'll have to rethink situation, but mostly happy compromise with battery being in a high stress environment.
ENgine bay isn't a big no no, but it's not desireable if you have better options...