Alternator and 2 dif types of batteries
Submitted: Tuesday, Mar 28, 2006 at 19:47
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Pyalong
HI Guy's,
Would be interesting to see if people think...or know....if there would be a reason why I could not have a AGM (Absorbent Glass Matt) battery as an auxillary battery, whilst still having a normal wet cell (I presume) 670CCA battery as the main battery for the starting motor.
I have had mixed reports...stating would be ok....to not good at all, one being due to alternator having difficulty (of some sort) in charging both batteries, because they are not the same????.
I have a dual battery system (obviously), with the auxillary used only to power a 12v trailblaza fridge (60l). The aux is isolated automatically when the ignition is switched off..by some sort of automatic thingo???.
I am just trying to gain an extra 24 hrs off power for the fridge, before I need to run the car to recharge the Aux Batt, and have had reports that the agm batt may be the way to go.....and is ok to receive a good charge from the alternator compared to a deep cycle, in reletively shorter space of time. Altough, have heard from one source...that its not actually much different???.
If it hasn't been obvious...I am not very techo with electric's....but doing my best to sort it out!!!!!!.
Cheers,
Mick.
Reply By: Member - Norm C (QLD) - Tuesday, Mar 28, 2006 at 20:37
Tuesday, Mar 28, 2006 at 20:37
Pyalong, your head will spin with the amount of info available on this subject via a
site search.
In my view Fr has it right. I run a vented starter, a vented deep cycle in the engine bay and two 120AH AGMs in the CT. When charging, they are often all connected in parrallel. I've had the set up for a bit over a year and it works great. Certainly no ill effects from mixing batteries.
If the DCs are run down, they take a while to charge ( the DCs are like a 345AH battery when they are parralled). But that is to be expected. I also carry a generator and 25 AMP multi stage charger. My isolator is a simple solenoid. It works fine, but I'd suggest a Redarc or similar voltage sensing unit is probably better.
AnswerID:
163522
Reply By: Sand Man (SA) - Tuesday, Mar 28, 2006 at 21:45
Tuesday, Mar 28, 2006 at 21:45
Mick,
Simple mate.
YES YOU CAN.
I have been sucessfully running an Exide Extreme (wet cell) as the primary, an Exide Orbital (AGM) as the auxiliary mounted in the engine bay and another portable system (AGM 75 ah Thumper) usually travelling in the rear, but charged from the alternator via its own dedicated in-car charging system.
The AGM battery IS the way to go, if you can justify the extra cost. The AGM will charge faster, more completely and allow a deeper discharge without permanent damage to the battery. Add to this the fact that AGM batteries are sealed and therefore wont spill and can be stored/charged inside the passenger area of the vehicle as they don't generate explosive gases and basically, they don't have any negatives whatsoever, apart from a slightly larger size and a higher purchase price compared with an equivelent deep cycle wet cell.
Any limitation to the contrary would only be the result of a badly designed and poorly performing Controller or Isolator.
AnswerID:
163544