Duel Battery setup

Clive
If the switch you have has a simple red plunger type twist handle, in the up position or with handle removed only your main batterey is charging and in circuit,locked down both are on charge and on current.demand
The easy way is to buy a connecting solinoid for $29 from super cheap(not a starter solinoid) this allows you to as you go to start and thence run position on your key ring(giving you 2 batteries on start command and 2 batteries on charge ,on run command when you remove key 2nd battery only stays on line to run fridge ect be sure to connect power to energise solinoid from 1st battery and wirered into run position on wirering loom at key station
Maurie

clive

I think you should also get id of it if you are unsure of what does what, i agree with Klaus use a simple method. I use a 4 position battery isolator switch from Hella (batt 1, batt 2, both, off,) The alternator charges the nominated battery selected by me manually (i like manual things that way i KNOW if they are working ,see I'm an old bugger) The alternator is capable of charging both batts at the same time, how do i know this ? ? i put a meter across the batts and both get charged at 13.8 volts. he advantage is obvious ....I know what is being charged and it forces me to open the bonnet daily to flick the switch over and generally look around. best of luck in a complicated world that doesn't need to be complicated*@$#%&#@"@$#%

regards jeff with an uncomplicated 1999 model 1HZ non turboed troopy

Hi Clive G, I’m not sure of the operation of your switch but if you have a multimeter, it will take you a few minutes to workout it’s operation.
Have a note pad and pen handy and have all the electricals in the vehicle turned off, EG, fridge, lights etc.

Start by measuring the voltage across the terminals of both batteries
and note the position of the switch.

If the reading is the same or within about no more than .1 of a volt then the batteries are probably connected through the switch but to make sure, go turn the headlights ON on low beam and go and measure the 2 batteries again.
If the volts are the same on both batteries ( although it should be a lower volts reading than before ) it is pretty safe that the switch is connecting the two batteries together.
If the volts reading is lower on the vehicles main ( cranking ) battery then the switch is isolating the 2 batteries in that position.

Turn your headlights off and then repeat the test in each switch position.
This will give you an idea of how the switch works.
If the batteries are connected together before you started, they will have equalised and have the same voltage reading.
The reason for turning your headlights on, is to cause a voltage drop in one ( or both batteries if they are connected together ).
Hope this helps you sort out the switch. Regards

PS. I would strongly recommend against installing an ordinary solenoid as this is the best way to end up with 2 stuffed batteries.

Clive,
Try Cray man's Idea with the simple solonoid system.
I have this in my Gu and it has worked well for 4yrs. IE. both bats are conected when the ignition is on and running and when the ignit is not on then the main bat supplies nothing and the aux bat runs the fridge external lights and other gear via a 4 cig lighter type outlet.