I was thinking of doing a dual battery set up been reading a bit bit would like first hand experience
which battery’s did you use and how did you fit them in
also which battery isolator did you use ( brand ) and does it do a good job on not discharging the main car battery ?

pictures would be great

 

In my Tacoma I've got a Northstar AGM starting battery, DURACELL deep cycle agm house battery, and blueseas SI-ACR and Solar. Pretty simple setup no extra manual latching functionality.

 

I use an isolator called "Battery Doctor" and a second battery in the trunk in a battery box. AWG-4 wiring goes along the right side frame and through the body behind the tail light. The isolator connects both batteries when the alternator voltage is high enough, otherwise they are always isolated from each other. I can take the second battery easily out (150A Anderson connector) for charging at home or use it as power source for charging phones and stuff in the tent.

 

One thing to think about is your needs/wants with the dual battery. Mine is setup for a house battery (phone chargers, camp lights, fridge, and other household amenities) with 2-way charging with the solar and alternator using 10awg wire. A setup using thicker wire can be used to self-jumpstart, provided the isolator supports that. Which I didn't need with the solar setup, but I carry a portable jumper pack anyways.

 

thanks for the info. I’m just starting to learn about how all this works I would want it for your purpose. Running lights chargers etc.

are there different types of battery isolators ? One that does not let main battery drain but only lets the accessory battery drain ?

 

Just gotta read the feature set on them. Most will likely allow the starting battery to run down to a point and then disconnect it so you can still start your vehicle. The Blueseas ACR line has specs laid out pretty well in their technical docs online.

As an example(not exact numbers):
The ACR will connect both battery when it senses a charge source of 12.5v or higher for 30secs.
Will disconnect with voltage lower than 12.5v for 2mins; or 12.3v for 30secs

 

I used a kit by Keyline (available on Amazon) which uses a voltage sensitive isolator, I have to say it works really well, when the truck is on the “truck” battery and “house” battery (deep cycle marine) are connected in parallel but when the truck is off they disconnect so that when loads pull on the house battery it doesn’t effect the truck battery. I wired up a small electrical panel in the back with some plugs, charging ports, volt meter, and a switch. In addition I have roof lights, a (very) small compressor, a dual band ham radio, and a socket wired up to the roof rack so it’s available for my roof top tent. That last one is the most useful, we can charge phones, run lights, and a small fan all night up in the tent (or use our heated blanket in the winter).

I highly recommend planning out where you want power and how you intend to use it plus leave some room for expandability. For what it’s worth, my battery is in the back storage compartment on the passenger side and I run a 7awg cable in a split loom back from the battery isolator under the hood all the way back.

 

thanks for the information

 

Found some pictures:


Battery in the trunk.

Connection at the starter battery.

Battery isolator in the jack cubby.

Holes for wires behind the tail light (one is for an external 12V outlet under the rear bumper)