Hi all,

I’m about to set up a second battery in the tray of my 2013 BT 50, after spending hours online looking at different set ups I still have a burning question, why can’t I just charge the battery directly from the alternator? Why can’t the alternator do the same for the AUX battery as it does for the starter battery?

I’m told that my alternator isn’t a ‘smart’ alternator as fitted to the newer model. No doubt I’ll need to have an isolator somewhere but the huge cost of a bc/dc or dc/dc charger seems over the top. 

I just want to run an 80litre fridge (I know its too big but it’s what I have) and some lighting. I have a 130amp battery.

Just hoping to get some lived experience from the good people of this site.

Cheers Rick.

You can, but without an isolator running accessories just drains them both,.  In effect you've just made your cranking battery bigger.

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Thanks Alex,

So as long as I isolate the AUX battery when the car is not running it won’t drain the starter battery and remember to reconnect so it will charge the AUX battery while driving 

I’ve ordered my tray and canopy for the ute (yay) and plan to have it connected with an anderson plug.

So if I just pull/connect the plug as required it should be ok?

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Thanks mate 

I’ll be getting an auto elec to do the work. I just didn’t want to be pressured into getting gadgets that I don’t want 

thanks for your help 

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No worries I’ll show you my set up I’ve got fused battery terminals love ‘em

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Redarc SBI12

Simple and foolproof.

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Yep +1 for the Redarc SBi12 under the bonnet with a 50A fuse between it and crank battery.

That is a 60A resettable circuit breaker on the back wall. This is in the back of my Discovery.

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