Dual battery system

[TonyP]

When I'm lucky enough to find my 4.8 GRX, where would I mount the second battery. It doesn't look like there is any space under the bonnet and I assume I would have to have it in a battery box in the cargo area....not ideal.

[Tinus lotz]

Temps in engine bay are to high for camping batteries .....put it in the back

[Clem]

Which reminds me…as soon as I am quite done with the trailer, that is likely to be my next project.

[Peter Connan]

Tony, somebody on this forum has managed to fit a second battery in a 4.8's engine bay, but as Tinus said, the temperatures in there are not good for a battery, and particularly for deep-cycle batteries. You can expect the battery life in half for a deep-cycle in an engine bay.

I have looked extensively at mounting a second battery under the body, next to the chassis legs, but the space just isn't enough.

So, I guess the answer is to stick it in the back after all...

[Kagiso II]

Tony .. Halo again .. GRAHAM showed me a much cheaper [and better ??] option .. a dry cell 40 amp hour battery half size of a shoe box, and you can even mount it upside down ... and the engine bay heat has no adverse effect on it [wellll maybe a little ] Graham can tell by now ..

I already have a PORTABLE power unit for the outreaches with a 105 AH battery .. so for now I dont need the dry cell thingy -- BUT when this deep cycle goes, that's where I am going .. dry ceel Duracell little battery

[Alex Roux]

In terms of battery life, I installed my deep cycle in June 2010. It was my first mod.
I have had the same battery inside the engine bay until about a month ago. So that was 4 years, which I think is a good lifetime for a deep cycle.
If I was more diligent with a charger and managed the recharging cycles better, the life time could have been longer.

I am therefore not too worried about the heat.

However Graham advised me that the National Lunar system does not charge fully and therefore ends up wasting charging cycles.
Therefore, unless you have solar panels and intend to stay over for more than two days at a place, away from electricity (where the deep low charging cycle may get called upon), you might as well insert a normal high cycle (crank) battery as your second battery.

The life cycle is therefore limited, not so much because of the temperature, but due to the limited number of charging cycles.

But in the 4.8 space is admittedly a problem.

[jan.dup]

[jan.dup]

Tony, have a look at this thread

http://patrol4x4.co.za/viewtopic.php?f= ... 9&start=20

on page 3. I have a 2nd battery fitted in the engine bay on my 2010 4.8GRX. Battery life is not as good as installed in the back of the Patrol - but nothing too serious - and I have driven in temperatures of well over 40 degrees Celsius for 3 weeks plus at a time without hassles.

First battery lasted round about 2 years - now on my second, second battery

[TonyP]

Thanks Guys, all good info and thanks for the link and pics Jan.