Second secondary battery

[tkn]

Hi All,

To allow extended stops I run two spiral wound auxillaries - they are small buy very heavy. I would like to place them under the bonnet but I am concerned it will be too much weight for the guard.
The car also has a turbo so heat is also a concern.
Tempted to put them in the back close to fridge

If you mount one in a well built cradle (e.g. ARB or similar) there should little stress on the guard.
The cradle should be mounted as near the front of the engine bay as possible - so cool air passes over the battery and disperses (a) fumes; and (b) any heat.
The other battery should be as close to the fridge as possible BUT make sure you have at least 6 square millimetre cables connecting the fridge to the nearest battery and at least the same size cables connecting the battery in the engine bay to the battery nearest the fridge AND good quality fuses in each positive cable.

Any "dry" joint (i.e. a joint that does not have a near 0 Ohm resistence) will create heat and lots of it - often enough to melt things. So it is best to solder each joint in the cable. Then make sure the slides (or whatever) on the fuses are clean and are near 0 Ohm connections when fitted.

Keep in mind that mounting a battery inside the cab does present a safety hazard e.g. fumes, spilt acid, etc. However, these may be reduced by mounting that battery in a battery box, which might also make it portable for locating the fridge in a tent, etc.