I bought a car a few months ago, and i'm finally getting around to putting a stereo into it. the factory battery was done, and was located IN the wheel well, so I replaced it with an optima red top and relocated it to the trunk for easy access. I pulled this battery from my last vehicle, and it was running hooked up to a second HO alternator mounted in place of the air conditioning, and this alternator and battery were dedicated to the subs, nothing else. after i pulled it, i didnt bother checking the voltage or charging it, and when i installed it the voltage had gotten kinda low, probably drained it.
now that its in my car, i've been checking the voltage regularly. after i charge it on a battery charger, and let it sit for a couple hours, the voltage holds at around 12.7-12.8. After its driven a few times, mostly in town, sometimes going out of town, the resting voltage without any charging is around 12.1 or sometimes as low as 11.9. the car starts just fine, and every time i've checked it, it's been below 0 or single digit temperatures, and i'm not sure if that has somehow been affecting the voltage. one time i checked it right when i got to my heated work garage, and it read 11.9. I let it sit for an hour, and the voltage went up to 12.0.
when the car is running, i get plenty of voltage. it's always read 14.4 or better.
once i install an amplifier for subs, i'm afraid i'm going to be taxing it too much and something's going to give. i'm hoping to figure out if its the battery or alternator before it happens and replace what needs to be replaced before it leaves me on the side of the road in minnesota winter.
my guess is its the battery, but i wanted to hear other opinions before i go throwing money into it
