Auxillary Batteries

Thanks for your helpful replies.

The Liemack fridge _Affordable_Storage_Drawers.aspx about 8 amps when running and would run about 10 times during the day and once or twice at night. It would use about 24 Ah a day.

The batteries were fully charged at the start of the trip. Last year we did a lot of driving and as I mentioned, the regulator wasn't working well and after we replaced it, things improved.

This year we stayed in the same place for a couple of weeks without much driving. The Century deep cycle lasted over 48 hours before the fridge switched off which means it probably had less than 40% capacity left.

We should have put the generator on it sooner because even if it was putting out 10A as specified, it would still take 5 hours to charge even without the load of the fridge. I am sure that we never got a decent charge into it except on the long trip home.

I have used 8mm2 cable from the solenoid to the aux battery and the voltage drop is about 0.01v.

Since I got home I have set up an 80w solar panel through a regulator hooked up to the century battery with the fridge plugged in. It may not have quite enough output to replace that used by the fridge but it should go close.

One last question:- even though it is not ideal, many people seem to successfully run their starter battery and their aux battery in parallel via the solenoid so can I have the exide and century batteries connected as a bank running in parallel with the starter battery via the solenoid?

Hi richor, first off, if you just have the solar panel fix in one position then your average hourly current output is only going to be around 1 to 1.5 amps which is not going to be enough to charge and maintain the battery and run the fridge.

As for using you main battery as additional power when stopped, there is no reason for not using it as long as you don’t let it get below 12 volts as this is the point beyond which it will becomes a problem to start your vehicle.

The cable size is fine providing it is not to far from the main battery to the auxiliary battery and that you have run both a positive and the negative cable.

As far as the charge time from the generator goes, there are some many factors that come into what is needed that you are just going to have to hope you get enough of a charge each time you use the generator.

Cheers.

It is a bit difficult trying to explain everything in this forum and I have missed out telling vital information but the answers have been great. Thanks for that.

I am pretty sure the generator didn't put out 10A. I spent too much time measuring voltages of the main and auxillary batteries but didn't measure the I from the generator. Its o/c voltage was about 30v but only about 13v connected to the battery. It definitely struggled.

I guess I am trying to do too much with not enough. Weekend trips don't cause any trouble but 2 - 3 weeks on the side of a river do.

I now have to look at other options for long term stays.