Dual Battery System

Hello there Jimny fans,

I'm glad that I found this forum. I want to ask if anyone has installed on his/her Jimny a dual battery system. I have installed Led Light Bar, Inverter, Winch, air compressors because me and my friends love road trips and campings. I love to be prepared for anything and I would love to install a second battery as an emergency. Does anyone know what do I need to change or install extra in order to manage a thing like this? 

Until now I have: 
The switch to isolate or connect the second battery.
www.google.com/search?q=Easy+Install+Car...imgrc=SLl2iZSVSeTiQM

And the isolator 
www.google.com/search?q=Car+Starter+On/O...imgrc=tmLVCL4TSEKUOM

The second battery I will connect it manually (with the switch) in case the primary runs out of juice or when i connect anything heavy load. Do i need anything else like a bigger alternator? or Rectifier?

Any suggestions will be welcome. 

Suzuki Jimny 2002 Manual

Thanks for your help.

I have this system... www.nationalluna.com/product/battery-manager-diy-kit 

It works really well. It leaves the second battery disconnected for the first 5 minutes after starting, then connects so that both batteries charge.  It has an override that allows you to jump start from the second battery, or so that you can use the current from both batteries for winching.

I use a Victory Energy Cyrix. This combines the batteries if the alternator is charging and the starter battery is sufficiently charged. Otherwise the batteries are disconnected to protect the starter battery from draining and allow a quick charging of the starter battery. All my additional consumers are connected to the second battery.

Make sure that:
- the wires connecting the batteries are sufficiently sized. I found that truck starter cables are the cheapest thick cables to buy. With 70A from the generator and 2m length I would use 35mm2 or even 50mm2. With 50mm2 or more then this could also be used to support winching.
- Install a fuse close to the battery.
- And for the Cyrix you need a D+ connection (alternator charging) which is located e.g., in the fuse box close to the main battery.

The additional cable and the Cyrix close to the main battery
 

A picture of the harness before installation
 



 

A few pictures of me installing my dual battery here: www.bigjimny.com/index.php/forum/6-jimny...mny-today?start=4572

I used the 'T-Max Split Charge' system (www.amazon.co.uk/Charge-Battery-Charging...onitor/dp/B00ZCOME44) which works really well. Nice little indicator thing which sits in the cab. Good system which lets you connect/disconnect batteries when needed OR leave it to sort itself out and keep the battery topped up. 

Run all the extras off the aux battery through an additional fusebox located behind the glove box which I run extra's off. I have an inverter in the back (2000w) which runs directly from the aux battery through larger higher amp cables.