craz28

iTrader: (10)

Last night i was playing music with my subwoofer on for about 15 minutes without running the car. The battery drained and I had to get a new one. Now its at 13 volts after barely one day of use. It went down about 1-1.5 volts and I was wondering if thats normal or my alternator isn't working. If you guys can just tell me whats your usual voltage that would be great, or if you can tell me if it is my alternator or not that would be great too. Thanks ahead

01WS6er

iTrader: (2)

did you check your battery after you just shut the car off or had it sat for a while. If you checked it right after you shut the car off than it will be normal for a batt to have 13V, your batt had a surface charge on it due to alt charging 13.5 -14.0 volts. If it sat for a while than you checked it than your alt may be overcharging. Also what batt are u using? What are you getting at the battery while engine is running?

2001NBMZ28

No system, but mine always starts above 13 and after a few miles settles down to about an 8th of an inch past 13 on the stock gauge. Do a cold start and put a DVM on the terminals...or give is a few cycles, maybe the battery you got has been on the shelf for a while. Did they load test the old battery?

craz28

iTrader: (10)

I tested the old batery at pep boys, it was bad. I get around 13.5 when i am driving. so far it hasnt came down. Its an energizer one for 60 bucks, and the old one was stock.

MIGHTYMOUS327

13.6 to 14.2 is the range i have seen alternators put out while the engine is running and no electrical loads are on. your charging system is working properly. btw 12.5volts is a fully charged battery.