My battery charging question, please come inside!

[newls1]

First of all, this is my charger ( http://www.etoolcart.com/102amp612-voltaut...ersol-1014.aspx ) I have a few questions to ask in this thread, questions that I've been wondering about for awhile, but never asked.

I have 3 batteries in my tahoe, 2 G31 DEKA 9a31's AGM, and 1 DEKA G78 AGM upfront (So all batts are in the same family) My resting voltage after the truck has been off for 6+hours, is 12.85v (all batteries connected to get this voltage) I would like to get a resting voltage of 13 if possible, so I dug out my charger from the pile of crap it was in, and I have 3 setting on my charger, and they are:

1. 12v 2a charge

2. 6v 10a charge (I will never use this as it is for a 6v batt)

3. 12v 10a charge

I used the 2a 12v charge, and my voltage goes to 13.4v, so I let it charge for about 30 minutes (all batteries connected) then stopped it, and checked voltage after about 2 hours of letting it rest, and the voltage is still 12.8.

I reconnected my charger and set it to 12v 10a, but my voltage raised to 14.3v, so I stopped, as I wasnt sure if this is to much to chage an AGM type batt with. Should I have kept it on 10a charge? Is a 2a charge just not enough "BALLS" to charge a batt with, or is a 2a charge more or less like a battery maintainer type of charge, trickle more or less.

If I am told that the 12v 10a charge is OK to use, how long do i keep the charger on the batts for? and is it ok to leave all the batts connected in parellel while im charging, I dont really want to disconnect my batts.... Thank you for any assistance you can help me with.

[lanman31337]

As long as it doesn't go over 15 volts you should be good. Vented lead acid batteries can charge higher, but not sealed or agm. You can leave the battery bank connected all together.

[newls1]

Thanks for the fast reply bro Doing a little research on this charger just now, It doesnt mention that this charger is designed for deep cycle batts. The higher part number Solar Charger 1160 is for deep cycles. Am I actually hurting my batts by using this charger?

[lanman31337]

You're not really hurting them, just not conditioning them the best they can. Shumacher makes a fairly inexpensive charger that you can select wet acid, agm, or sla on it.

[newls1]

would it be bad if I stock my charger on my batts at a 2A charge (which feeds about 13.4/5 Volts to them) and let them charge up for about 4-5 hours? Will this maybe keep the resting voltage @ 13v??? I just noticed today that while the truck is off, while I have my radio on (only 1 4channel MTX amp on) my voltage goes to 12.5 almost instantly. I have 3 very good batts and thing that is just to low for my liking. Maybe I should keep the charger on them for 6+hours @ 2A charge? Feedback here please..... Thanks

[Iraggi Alternator]

You need to put it on 12 volt 10 amps overnite to even come close to fully charging that much battery capacity. thats only 3-4 amps per battery.

Dont worry about your voltage going over 15 while they are charging. As long as they are not getting too hot. If they never get hot, they are not fully charged. IMO.

Your batts fully charged will stay over 13.2 for hours when you take them off the charger.

Most chargers when left on for long periods of time will taper off on the charging current mainly because the voltage is getting higher. This will keep the batteries from too much charge.

[newls1]

thanks bro......

[Boon]

I give my big AGMs like 16v+ to give them a kick if they've been sitting for a while.

It's harder to fully charge an AGM than a vented. If your alt is doing much less than 14.4v then they're probably never even getting a full charge.

[lanman31337]

Don't run them at higher charging voltage for long periods of time. They'll sizzle and hiss at ya!

[newls1]

I give my big AGMs like 16v+ to give them a kick if they've been sitting for a while.

It's harder to fully charge an AGM than a vented. If your alt is doing much less than 14.4v then they're probably never even getting a full charge.

With my dual alt setup, and MLA combo, my crusing voltage while HOT is 15.1/15.2. Startup voltage is 15.5, and remains there for about 10minutes, till of course heat starts to build up.