240SXtoTC

i just had a new pioneer cd player installed and it has a battery voltage meter on it.
when i'm driving it usually reads between 13.1 and 13.7.
A friend told me that it should be at 14 and something is wrong but I don't know if he really knows what he's talking about as my car starts and runs just fine...
the only other mod i have done is a viper security system (no subs or anything yet)
just curious to see what you guys think.

ScionDad

You're fine. The accuracy of that meter is at least +/- a few mv. I have 3 stinger meters on mine....13.8v at the battery, 13.6v at the amps and 13.4v at the cap. 16 feet of wire along with the accuracy of the meters is my difference and it varies all the time.

engifineer

Yep, no issue. If it reads 12V, then start checking I believe (and I am digging into my memory here) that it takes around .2 V per cell to create the reverse current to charge a lead acid battery. I think these are 6 cell batteries, so technically it should charge at 13.2V (.2 * 6 + 12). I usually go with 13.5 - 14.5 or so to be ok.

mandos

My battery sits at a constant 13.4V almost always. With the car running usually about 14.1 to 14.2. With the 2 Nine.1's running at full tilt, I sucked it down to 11

RanmaP

I would agree, if your alternater isn't charging then upper 13 is good, when your car is on and the alternater is working then it should be over 14.

Newtmaker

I think probably 99% of auto's out there call for a charging rate of 13.6 to 14.2 . If you are in that range you are fine. If you are consistantly high or low then you can expect problems down the road. Too high and you cook your battery, too low and you cook your alternator/regulator.

Walt

engifineer

No, it should sit at 12V without the car running. It may read a little over due to meter discrepencies and overcharge, but the minute you add a load you should see 12V. 13.4 and up are the charging voltages.

If you are seeing it drop to 12V or below while running (for longer than a couple of seconds at a time), then plan on an alternator soon, because you are running yours past its capacity. The alternator is burdened with supplying the system loads plus charging load while running, so if it is not holding battery voltage to proper levels then you are overworking it.

Lonely_Raven

These guys are so smart!

I like when things are laid out so clear and concise!

240SXtoTC

my thoughts exactly... thanks everyone for all the info

sciontc_mich

yeah mine is reading 13.1-13.4 volts.. a/c kicks on it goes down to 13.1v. just my $0.02