Thread: Do I NEED a second battery?

Yes and Yes...

Bigger main battery + Aux Battery

On those figures your max amp draw is about 8.1 (@ 12 v) so you should be okay for 30 mins -

With the amp (50w) amp draw would be about 11.5

...........but when you start adding the compressor etc., you would want to run your engine when you are using it.

According to my calcs that would draw about 7 amps if all running simultaneously. I have been running my Thermoelectric fridge all day (8 hours) 5 days a week for a couple of years now. This unit draws 5 amps, however I am on the road for about 4 of these hours so I do get a top up charge. I do not have a 2nd battery but rely on the cranking battery. I have run the fridge for about 7 hours at a stretch without any problems. If you can afford it would be better to go the 2nd battery option I think.

maybe a bit more info should be given here.

My RRC is a weekender I drive it 70-80% off road and when off road it's usually a full day or maybe half a day at a time.
The reason I mentioned 30mins without running the engine is because in general that would be a lunch break.

Tyre compressor is only ever run with the engine running.

I also read somewhere that running a battery flatter than about 80% of full can damage the battery.

If in doubt - bung a 2nd battery in

It doesn't cost an arm and a leg

................better safe than sorry

Shout it a new cranking battery and use the original as your aux with a cheap simple controller.

Get a second battery, get a Traxide Tronics smart charger from Traxide (drivesafe) and connect it all up.

I run a laptop off my second battery for maps and also charge batteries and run my 40lt 12v fridge, i have even charged the laptop, camera, Ipod and the camper battery overnight while still running the fridge.

Baz.

I only have 1 battery in my D1 and run all sorts of things off it, including winch, engel fridge (for up to 16 hours at a time) electric compressor. I watch what I am doing to make sure I dont flatten the battery but dont have a problem. If in doubt fit a voltmeter. Oh and btw it's an optima battery and I think that helps A LOT.
OK an optima will cost more than a wet cell however one battery saves on space and weight. You avoid problems of killing a good battery by having a dud in the system and they last longer than wet cell batteries also.
Yes I am happy with my optima.