Steve Campbell replied:

I've used one before I put in my dual battery setup. It was good as it was not tied to the Troopy (ie I could put in next to the tent if I went for a drive). However, I found the capacity was not great, and it took much longer to charge than my Optima Deep Cycle. I suppose it depends on how often you'll used it.

porl replied:

I suggest that if money is an issue and you will be running the car almost every day - don't use the battery pack to run your fridge, use it to start you wagon if its battery is ever run down by running the fridge off your accessory outlet every day and night. But be sure to change your battery for a heavy duty one that won't usually run out overnight.

Patrick replied:

Hi Ian - I had a simailar question on this site back on 24 October and receieved some interesting feedback.

In my case I was looking at a Thumper unit to power my Waeco 52 litre fridge because at that time I understood that a 2nd battery system could not be installed in my Pathfinder. I subsequently found through an aftermarket dealer in Brisbane that I could. The 2nd system cost $650 which was for an Parnaha tray with an Optima deep cycle battery plus 2x 6amp cables to connectors in the rear. The Thumper alternative was $700 - $750 and I found through the advice received that it would only run my fridge for around 24hrs before charging would be required. The charging process is very slow and could take up to 18hrs to conmplete.

There were plenty of people who said that they liked the Thumper but I also spoke to extremely experienced off-roaders and a couple of local 4wd shops who said that they are more suitable to low ampage use rather than powering a fridge.

A normal Danfross 35 condenser can use up to 4 amps per hour when the conditions are hot so it does not take much to draw down a 48amp battery. Remember that you have to allow for a cut off at around 20% of that.

I believe that after all the advice I received that my decision to install the 2nd battery sysyem was the more practical and cost efficient way for me for the future.

For more info try doing a search of Exploroz.com by simply going to the search option, typing battery packs of power packs and up it come.

Best of luck