Re: Placement of 2nd Battery
Posted: 21 Aug 2011 07:37
Gentlemen
Having learnt some hard won experience, just be aware of the following:
There are a couple of additional concerns when placing the 2nd battery in the engine bay of a 4.8 with ABS, particularly if you place it next to the 1st one:
1) mass is all on the drivers side (26Kg per battery), so if you drive alone, then you are looking at 54kg + driver (75 - 100 kg), a constant load for which the coil spring on that side was not designed
2) the 2nd battery is then very close to the engine and the 4.8 gives off a fair amount of heat. Battery + heat = not a good combination = very short life
3) make sure the batteries are the same size. Unless you have a very intelligent 2nd battery charging system, the smaller battery will get fried over a period of time as the alternator sees the overall load and supplies charging current accordingly.
4) and do not place a gelcell under the bonnet, it does not do well under the heat conditions found close to the engine!
I like Wilfred's installation. Unfortunately I do not have a drawer system in the back of the Patrol.
What I have done is to make a 12 mm marine plywood board in the shape of the rear compartment floor layout. I covered the board in automotive carpet and bolted it to the floor using existing Nissan bolt holes that all have nuts welded to the chassis side. (14 in total - small and large)
In this board I have added slots through which I rigged straps. These straps tie down my 50L water tank when in use. Where I do not require the water tank, the straps are used to tie down the National Luna 2nd battery set up (the grey box) and my recovery gear ammo box. In strategic places I also fitted those nuts with the upturned sharp edges that "bite" into the wood. These allow me to bolt down the fridge and the battery when I do use my water tank.
To power the grey box I installed a heavy duty welding cable to the rear of the car from the 1st battery. I have a 175A Brad Harrison connector for the trailer battery and from this I tapped off power to a marine fused distribution panel. Now I can add any equipment to the rear, just connect it to the supply.
In addition I added a red 50A Brad Harrison plug next to the marine DB and that is used solely to charge the grey box. Another grey 50A BH plug is available for equipment that draws major current (compressor etc).
The setup has worked well to date, however I would still like to make provision for solar panel charging when I camp for more than 2 days in one spot - fortunately this does not happen that often, as we prefer to move on and explore other areas!
Hope this gives some food for thought.
Herbie
Having learnt some hard won experience, just be aware of the following:
There are a couple of additional concerns when placing the 2nd battery in the engine bay of a 4.8 with ABS, particularly if you place it next to the 1st one:
1) mass is all on the drivers side (26Kg per battery), so if you drive alone, then you are looking at 54kg + driver (75 - 100 kg), a constant load for which the coil spring on that side was not designed
2) the 2nd battery is then very close to the engine and the 4.8 gives off a fair amount of heat. Battery + heat = not a good combination = very short life
3) make sure the batteries are the same size. Unless you have a very intelligent 2nd battery charging system, the smaller battery will get fried over a period of time as the alternator sees the overall load and supplies charging current accordingly.
4) and do not place a gelcell under the bonnet, it does not do well under the heat conditions found close to the engine!
I like Wilfred's installation. Unfortunately I do not have a drawer system in the back of the Patrol.
What I have done is to make a 12 mm marine plywood board in the shape of the rear compartment floor layout. I covered the board in automotive carpet and bolted it to the floor using existing Nissan bolt holes that all have nuts welded to the chassis side. (14 in total - small and large)
In this board I have added slots through which I rigged straps. These straps tie down my 50L water tank when in use. Where I do not require the water tank, the straps are used to tie down the National Luna 2nd battery set up (the grey box) and my recovery gear ammo box. In strategic places I also fitted those nuts with the upturned sharp edges that "bite" into the wood. These allow me to bolt down the fridge and the battery when I do use my water tank.
To power the grey box I installed a heavy duty welding cable to the rear of the car from the 1st battery. I have a 175A Brad Harrison connector for the trailer battery and from this I tapped off power to a marine fused distribution panel. Now I can add any equipment to the rear, just connect it to the supply.
In addition I added a red 50A Brad Harrison plug next to the marine DB and that is used solely to charge the grey box. Another grey 50A BH plug is available for equipment that draws major current (compressor etc).
The setup has worked well to date, however I would still like to make provision for solar panel charging when I camp for more than 2 days in one spot - fortunately this does not happen that often, as we prefer to move on and explore other areas!
Hope this gives some food for thought.
Herbie
and must say on first inspection it looks a bit difficult to fit the battery in the engine compartment without fiddling to the extend of a broken warranty. Almost sure that I will have to go to the back with that - also makes sense what you say Herbie.