Am I overcharging my battery?

[BEEMDUB]

I have a 120 ah agm batt and my stock batt and I left my schumacher battery charger on a 5v slow charge all night on the agm...Well I dmm'd it the next morning at it was at like 13.63....Did it overcharge it? Or is that normal for a fully charged agm..

[xx1]

seems normal for an AGM

[Miguels]

it will drop back to resting voltage once you disconnect the charger... mine seem to charge the batteries till it gets to 14.2 to 14.6 then it shuts off. there is nothing wrong with that since thats what the alternator charges to

[BEEMDUB]

seems normal for an AGM

it will drop back to resting voltage once you disconnect the charger... mine seem to charge the batteries till it gets to 14.2 to 14.6 then it shuts off. there is nothing wrong with that since thats what the alternator charges to

alright just wanted to make sure thanks guys

[Phototini_xB]

The general rule of thumb is you can charge your batteries at 2-2.8 volts over the native voltage of the battery. So if you are using a 12v battery you can charge it up to 14.8 volts safely.

[SnowDrifter]

The general rule of thumb is you can charge your batteries at 2-2.8 volts over the native voltage of the battery. So if you are using a 12v battery you can charge it up to 14.8 volts safely.

Close, but not quite. The highest 'safe' charging voltage you can use is 2.4vpc - volts per cell. In a 12v battery with 6 cells, this comes out to 14.4v - a voltage that will produce virtually no gassing. But lots of members on here charge higher than that with no ill effects. Whether or not you can charge at 14.8 without issue is dependent on things like temperature and case thickness.

[Phototini_xB]

The general rule of thumb is you can charge your batteries at 2-2.8 volts over the native voltage of the battery. So if you are using a 12v battery you can charge it up to 14.8 volts safely.

Close, but not quite. The highest 'safe' charging voltage you can use is 2.4vpc - volts per cell. In a 12v battery with 6 cells, this comes out to 14.4v - a voltage that will produce virtually no gassing. But lots of members on here charge higher than that with no ill effects. Whether or not you can charge at 14.8 without issue is dependent on things like temperature and case thickness.

I wonder why many of today's vehicles charge at 14.6-14.8v?

[AMI CUSTOMS]

The general rule of thumb is you can charge your batteries at 2-2.8 volts over the native voltage of the battery. So if you are using a 12v battery you can charge it up to 14.8 volts safely.

Close, but not quite. The highest 'safe' charging voltage you can use is 2.4vpc - volts per cell. In a 12v battery with 6 cells, this comes out to 14.4v - a voltage that will produce virtually no gassing. But lots of members on here charge higher than that with no ill effects. Whether or not you can charge at 14.8 without issue is dependent on things like temperature and case thickness.

I wonder why many of today's vehicles charge at 14.6-14.8v?

Voltage drop or loss because of all the shit they have running so after the fact you get down to low 14s at the battery, many companies got smart and started doing PCM control to where the alt shuts down to save the life of the battery even further, us basshead hate those types of vehicles.

[Phototini_xB]

The general rule of thumb is you can charge your batteries at 2-2.8 volts over the native voltage of the battery. So if you are using a 12v battery you can charge it up to 14.8 volts safely.

Close, but not quite. The highest 'safe' charging voltage you can use is 2.4vpc - volts per cell. In a 12v battery with 6 cells, this comes out to 14.4v - a voltage that will produce virtually no gassing. But lots of members on here charge higher than that with no ill effects. Whether or not you can charge at 14.8 without issue is dependent on things like temperature and case thickness.

I wonder why many of today's vehicles charge at 14.6-14.8v?

Voltage drop or loss because of all the shit they have running so after the fact you get down to low 14s at the battery, many companies got smart and started doing PCM control to where the alt shuts down to save the life of the battery even further, us basshead hate those types of vehicles.

I understand that, but with just the average amp draw of an idling vehicle with no accessories turned on some vehicles will show 14.6-14.8 at the battery. For instance my wife's old 04' F150 would show 14.6 at the battery and my 01' Suburban would show 14.8v. I come from a much different but at the same time similar hobby of high power CB radio. So electrical systems is somewhere that our two hobbies kind of overlap. In the CB world our amplifiers are very inefficient and while transmitting are running at 100% duty cycle at max drive (where most of us run the amplifiers). So voltage and charging is very important even more so than in car audio. For instance we can't use the small case alts that you guys use because of the excessive amperage draw creates way to much heat and amperage output is nearly cut in half of the advertised output. It's not uncommon to see a competition CB truck running 6-12 large case 320a leece neville alternators and needing nitrous to turn them at 4500-5500rpm.

Most of us run separate charging systems just for our amplifiers at anywhere from 14-20v. And using a number of various batteries I've never seen gassing on charging at 2.8v over the battery/batteries rated voltage. I have seen batteries explode however from newbies trying to run a 16v system using a 12v battery bank, that wasn't pretty.

And don't get me wrong, I'm not trying to bash on the car audio guys. I love this shit too, but spent all my money in the past on CB stuff instead of car audio. But now I'm starting to get back into the audio stuff hence why I'm here. I just am naturally drawn to this section of the site because in my world the electrical system is the most important part of any build.

[BEEMDUB]

Hey guys I installed my battery relay I had and wired it up however, when it would activate it the second battery would be seeing lower than the first battery and then it would SLOWLY climb to near the voltage of the first battery..Does this mean my relay is just shitty and no good? It is like 5 years old, and the posts are pretty dirty and somewhat rusty...