Testing new dual battery system

[KM4 Lurker Find all posts View Profile Close KM4]

No doubt some will get a giggle out of this one, but here goes ... !
I have just finished installing a dual battery system, rear power outlets and Camper Anderson plug. However I don't actually have my auxiliary battery yet as I'll be getting it in a few weeks when I go to Brisbane. For the sake of going through the testing regime for the system, could I put the only other 12v battery I have from my ride-on mower(!) in the aux battery tray but only to check that the system is working OK, then remove it. The bit I'm mainly concerned about is where the engine is started to check voltages in both batteries. Is there a risk of frying the lawn mower battery with the alternator's output (or worse; smoke, sparks or fire!).

The installation instructions were fairly straight forward so I'm hoping it should all be OK, but if there are any glitches I'd prefer to find out now before I do the big trip to the city as I won't have time to stuff around with it down there.

[Crisp Image Member Find all posts View Profile Close Crisp Image]

Re: Testing new dual battery system

As long as it is a 12V battery and your vehicle does not want to crank off it then it should be OK. Remember if you are going to travel anywhere that you tie the small battery down so it does not walk anywhere.
Regards
Crisp Image

[lissted Member Find all posts View Profile Close lissted]

Re: Testing new dual battery system

Just use a multi meter on the terminals of your aux battery. After you start your car, soon after you should see a light or hear the relay click over and you should have charging voltage at the aux terminals. If this is ok hook the aux terminals up to the wires running to the rear and check the voltage at the back with the multi meter.