Dual battery Isolater capacity

Hi kcandco,

Without trying to guess how you want to wire the batteries to operate, I would suggest that you use a "Clohessy" 500 Amp switch or equivalent which will be able to carry the starter motor or winch current without fear of melting the contacts.

Cheers, Jerry.

Hi Kc

The Isolator must be rated to what the aux battery or batteries can draw. The most I have ever seen one battery draw is 44 amps. Please advise your battery type and size and we can assist you. Almost any isolator on the market will take care of a 90A alternator.

Regards

Derek.

Hi Kc

The Isolator must be rated to what the aux battery or batteries can draw. The most I have ever seen one battery draw is 44 amps. Please advise your battery type and size and we can assist you. Almost any isolator on the market will take care of a 90A alternator.

Regards

Derek.

You will also have consider if you wish to start your car off the Aux battery if your main battery dies. I always wire mine with a manual over ride switch supplied from the Aux battery so i can close the solenoid to start off the Aux battery if the main battery is dead..

Kc,
First question is, are YOU using a winch ?

2nd is; what's your first choice of battery isolator at present that's 80 Amp rated ?
I only ask to get an evaluation of price range, no good suggesting an elcheapo mechanical solenoid when you are prepared to invest in a decent electronic battery isolator for an extra few $$.

Question is;
What will run off the second battery ??
What capacity and type of battery will it be ??
Will the 'load' fully drain the second battery or is there a 'cut-out' device involved to stop fully draining the second battery ??


Hint: all electronic battery isolators (I'm aware of) are well in excess of the rating of your alternator !!

They are an investment, you remove it and use on the next vehicle.

Thanks everyone for your help!!!
I intend to have a 100AH Agm mounted in the tailgate of a Pajero wagon. I have a 12volt Bushman Fridge in the tailgate, drawing 5 amps and using up to about 40 amp hours in a 24 hr period. There is no winch or other accessories. I would probably drive every day but at worse case scenario would probably draw 80 - 90 amps from the auxiliary battery before recharging. I also have a Supercharge Gold battery 950cca and 200 minutes RA fitted to my camper but if necessary could use an andersen plug to charge one or the other (not together??) as the camper battery does not normally get much use (led/fluoro lights and waterpump). The battery isolator I have seen is a Sidewinder BI-80. I have also considered a Redarc which I can buy of the web for $95 + postage. Any other suggestions welcome.