[shrek]

First of all, Merry Christmas!

I have a problem with my dual battery setup. I am running a CAT 650CCA battery for the main and a CAT 750CCA for the aux. Using a Redarc 100A controller.

Whats happening is this: I will leave my fridge going all day (draws 3 amps when running), and within 10 hrs the aux. battery is flat. I realise that the battery is probably stuffed and not going the distance it should, but the plot thickens.

Yesterday at work i had the fridge going to keep our bevvys cold for knock off time and within 8hrs it was flat. I drive an hour to work so it has a good charge time. Also my 2way and stereo run off the aux battery. On the way home, fridge off (but full of ice) the stereo cut out on low voltage which means the redarc controller didnt connect the second battery. I went out to the car this morning, the aux battery had 11.5v. I started it and after about a minute, the redarc relay kicked in and the aux batt was being charged.

Why did it work this morning and not yesterday when i needed it too?????

It has done this once before and yes it is wired up correctly.


Thanks and have a good one,

Nath

 

[jimako]

Maybee loose connection somewhere, or bad/dirty contacts on the solenoid.

 

[outback]

agree with dirty contacs try gettting giving it a little tap and see if it turns on/off i had one doing the same thing what it was everytime i hit a little bump it turnd its self off.

 

[the evil twin]

Firstly... One hours drive is nowhere near long enough to charge your Aux from flat (11.5).

I strongly recommend get a load test done on the Aux battery. If it is recoverable then get it fully charged up... if it is knackered get a new battery. A decent aux should run the Frig for a couple of days easy and a dud one that has dropped a cell or two will fool the Redarc.

After that is sorted you can then begin fault finding the Redarc. Easiest way IMHO is with the engine running look for a voltage drop in the circuit. There is a few ways to do it but if the Cranker positive to chassis earth is say 14.3 then the Aux positive to chassis earth should be 14.0 or more. If it is say 13.8 or less then the Alternator charge isn't seeing the Aux so work your way back and see where the loss is.

Also check the voltage from the Aux negative to chassis unless you have a Neg cable from one battery to the other. The voltage should be almost zero but if you have a bad earth return path the reading could be 1 or 2 volts and that will also fool the Redarc/Alternator

 

[GU4.2ST-L]

i have the same system and i have two supercharge 760CCA batteries and my rest voltage is 12.7 so i think youre aux battery is stuffed i suggest as did evil twin did and get a load test done on it

 

[wrx198]

While your at it get ur main battery tested too, it could be low on voltage or unhealth hence the reason the relay wont click over on charge because it hasnt charged the main battery first

 

[Blake4x4]

try taking all the connections apart and get hit them with a rag then rough them up with some sandpaper and wipe them with a clean rag then see how you go
good luck