Cart (0)
You have no items in your shopping cart.
Friday, 19 August 2022 11:03:01 PM

Dual Aux batteries and power sockets

9 years ago
#43 Quote
Hi All.
I have just had a Redarc BCDC1225 installed with a RED anderson plug for solar panel input (reminds me that this is for unregulated solar input only) and a 100 ah aux battery under the bonnet of a 2011 Pajero. I also have an anderson plug at the rear of the car, connected to the aux battery. I intend to put a battery on the van and connect it via this anderson plug. I understand the 2 aux batteries should be the same type/capacity etc., so I assume this will allow the van battery to charge from the BCDC1225 too. I also understand that the van battery may take longer to charge due to some voltage drop, correct so far?
My next problem is getting power to my Waeco 60Lt fridge in the rear of the car. Would it be a problem to pick up power from the lead running to the anderson plug and insert a 12v socket in the rear cargo area? Would this compromise the van battery recharging? I have run out of room to get wiring into the cabin through the firewall so am looking for an alternative. The lead to the anderson plug is around 7mm or 8mm.
Bill T
9 years ago
#830 Quote
Hi Bill,

If you are to use the BCDC to charge the battery in the van also, then yes they must be the same type. You are correct in saying that you will take a greater time to charge these batteries given the distance between, and potentially the one in the van will not charge fully. The BCDC is designed to "pull" not "push", and should be positioned as close to the battery that it is charging as possible. It also may not see the van battery voltage correctly due to voltage drop, and will move to "float" prematurely. This will cause it to not charge the van battery fully.

It would be best to run another BCDC in the van, that comes from the anderson plug - fed by the start battery. This lead can be run down the chassis - under the cab, rather than through the cab, therefore your inside lead can be used to feed your fridge alone.
If you "tapped" off the current anderson plug lead with your fridge on the way to the van battery, you will be adding more current draw and voltage drop, therefore further reducing the ability of the van battery to charge, and potentially causing your fridge to cut out early due to low voltage.

Is the 7 - 8mm cable the measurement of the copper inside, or overall? If this is overall measurement, it is suitable for running the fridge, but not for charging the battery in the van. You should use at least a 6B&S cable for the van battery charging.