Battery Distruction - now alternator issue

[westernair]

OK for some reason my truck is eating through batteries. Back in Novemeber I replaced both of my batteries with marine grade ones as one of my batteries would not hold a charge at all. Just days before I was wheeling so I figured I must have broke a lead plate or something.
Since Novemeber I have had three more go out on me as well. Interesting note is it is always the one closest to the front of the truck.
Granted the warenty has been replaceing them but I dont want this to happen when out on the trail or something.
Anyone have any ideas on what could be causing this to happen?
Thanks in advance

[TechMOGogy]

any 12v accessories drawing off of the 1 battery?

[Jim LaGuardia]

Check charge voltage, also if you have a 24/12v converter make sure it has an on off switch.

[berger]

+1 on the converter. I went through the original set of batteries on my Iltis because of it...and my installation of course...

[westernair]

I have 2 24 to 12 volt converters. One dedicated to the EFI and one for accessories. The EFI is ignition switched. The accessory plugs are not and has power all the time.
Voltage going back in from alternator should be around 27 correct? Ill check tonight.

[berger]

The accessory plugs are not and has power all the time.

That was how I had it, and lost both batteries...well, they wouldn't hold a charge any longer. I didn't want to go down that road again with the Pinz because my electrical knowledge is sub-par for sure.

[westernair]

OK after moving the converter to a switched circut, I have still been noticing some battery issues.
In testing everything it seems my Alternator is putting out the 27 volts but only a max of 6 amps. Would a new set of brushes or something else fix this or does the entire unit need to go to an alternator shop?
Thanks in advance,

[Jimm391730]

The batteries (and other loads) are what defines the current coming from the alternator -- through the voltage regulator, the alternator current is adjusted to keep the ~27V output. If you were to turn on your headlights or other load, the additional current draw would make the battery voltage lower; so the voltage regulator tells the alternator to produce more current to make up for it.

In the daytime (and right after starting) the recharging of the batteries takes up most of the current from the alternator -- the ignition takes only a few amps. As the batteries come up in charge, their voltage does, too, so the regulator tells the alternator to decrease the current to keep the output voltage the same.

I wouldn't worry about the alternator's amps, unless the truck can't keep the voltage at 27V. This is why a voltmeter is important to monitor the health of your system. Any lack of current will show up as a reduced voltage. A voltage of 24-25 volts won't properly charge the batteries, and a voltage of 29 volts or more will be overcharging the batteries.

You can have battery problems even if you buy two brand new, identical batteries because they are NEVER exactly the same (although they will likely be closer than any other pair of batteries). One will have a little less capacity, and just starting the truck will have it drained slightly more than the other. Lead acid batteries will take LESS charge the further they are discharged, so that battery will never be charged as fully as the other (which actually is getting a tiny overcharge). The next time you start the truck, this problem gets compounded, again and again, and the batteries drift further than further apart in charge and capacity. Now in most trucks they are close enough together that this doesn't show up for years and then the owner says "well, must be time for new batteries". But all that is needed is the occasional independent charge to each battery; that is, put a 12V charger on ONE battery until it is fully charged, then charge the second battery in the same manner. This brings both batteries up to full capacity and "resets" the imbalance that gradually occurs. I do this with both my trucks about twice a year.

[berger]

But all that is needed is the occasional independent charge to each battery; that is, put a 12V charger on ONE battery until it is fully charged, then charge the second battery in the same manner. This brings both batteries up to full capacity and "resets" the imbalance that gradually occurs. I do this with both my trucks about twice a year.

Good tip!

[TechMOGogy]

Not to divert this thread but...
Jimm391730
How do you independently charge each battery? Remove all cables and put a 12v charger on each one or can you just put the 12v charger on the + and - terminals and then do the same for the other battery with all cables in place?
I am very electrically challenged esp when it comes to 24 volt.
Thanks,

[westernair]

Pull the jumper wire from the two, and the ground wire from the one. then charge each one indipendently

[berger]

Yup. I have a Deltran Battery tender I use on the Ural, lawn tractor and generator.....Now Pinz. I have been running the same OEM battery in my Ural since 2007 because if it. Sorry for the hijack....


Sent from my Mobile

[Jimm391730]

How do you independently charge each battery?

It is REALLY simple -- just hook the red terminal from the battery charger to the positive (+) terminal of one battery, and the black lead to the negative (-) terminal of the same battery. There is no need to disconnect ANYTHING from the batteries first (although it doesn't hurt, unless you re-connect it wrongly). If you have two chargers, you can also connect the second charger to the other battery at the same time; however, I prefer to use the same charger as so to "top off" both batteries similarly.

The simpler it is, the more likely you will be to do it!