sla secondary batteries

lynchie10

New Member
Hi all.
I'm hoping someone can help me. I have a 100Ah SLA, (Sealed Lead Acid, or Gel Cell) battery that I am looking to install into my GU. I currently have a dual battery system, and I am looking to install the SLA as a third in the back of the wagon. My question is, Do i have to do anything special to charge an SLA as opposed to a normal wet cell? or Is it OK to simply connect the battery up to the secondary side of the battery manager?

Thanks in advance
 

drivesafe

Active Member
Hi Lynchie, gel cell battery can be tad susceptible to over charging but with your planned set up, with the battery being mounted in the back, you are actually adding two safe guards that will pretty well eliminate any over charging potential.

With the battery being mounted away from the engine bay, the battery is never going to get very hot and this means, as the battery is going to be cooler, it can tolerate a slightly higher charge voltage, plus the length of the cable run to the rear of your 4x4 will help regulate the voltage.

You can simply parallel the new auxiliary battery with your existing auxiliary battery and while it will have very little effect on your operation, what type of battery is your other auxiliary battery?
 

lynchie10

New Member
Thanks Drivesafe
That's pretty much what I was expecting.
The other battery is a Hybrid Wet cell. Also known as a semi cycle. So far it has been excellent.

I was thinking of including a voltage regulator in the supply cable to limit the charge voltage. Do you think this would be worth the effort?

Thanks
 

lynchie10

New Member
Thanks again Drivesafe.

What size cable do you reackon I need to use? The run is about 5 meters, and I'm not sure what sort of charging currents I am dealing with..
 

drivesafe

Active Member
Hi Lynchie, with a run of 5 metres, I would recommend 6B&S twin sheathed cable, thats positive and negative 13.5mm2 cable.

Although this size cable is rated at 100 amps, it’s not the amps your after as the battery, even at it’s lowest state of charge, will not draw more than 25 amps. The heavy cable is to help reduce voltage drop.

The greater the voltage drop, the slower the battery will charge. By using 6B&S cable, you will greatly reduce the voltage drop and ensure your battery fully charges sooner.

PS, don’t forget to put 30 amp circuit breakers at either end of the positive cable, as close as possible to the positive terminals of your two auxiliary batteries.
 

lynchie10

New Member
Thanks again for your help Drivesafe.
I'll close off this thread with the result as soon as I get it installed.
 
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