Once I've fitted the charging system I'll have two batteries, the second's going to be an Optima YellowTop D31A deep cycle battery. L322's are renowned for being sensitive to low voltage so this should guard against that, plus I going fishing by myself for up to a week at at time miles from anywhere. A second battery is a good insurance plus I can use it to recharge my cell phone, laptop etc.Can you tell us why you need such a charging system on a L322 - do you have multiple batteries, and if so, why?
The National Luna system I've bought is fully automatic, both batteries are connected full time to the car via a controller which gives priority to the main battery. You can also override the controller and manually control which battery gets charged, I also get an indication of the charge state of both batteries. It prevents run down of the main battery from use of the second battery when the engine is not running. I do have a solar panel which I can also connect to the system to help prolong the second battery charge. For more information go to roversnorth.com and check out the description for it there. For information on how I'm going to install the battery check the following excellent write up on this site at http://www.rangerovers.net/rrupgrades/dualbattery.html With the right equipment and correct installation there is no reason to not install and use a second battery on a Range Rover for off the grid use.How is the second battery hooked up, A/B switch, in parallel, or something else?
I assume that only one battery is online at any time, or you risk killing both if there's a parasitic drain of some type.
BTW, where are you going to mount the second battery?
You should check out the Goal Zero line of battery power packs and solar chargers if you plan on spending time off the grid, and leave your vehicle alone.