Introduction:

Looking for a cheap dual battery setup for your Ranger or Bronco II?

Note: This will not work on the 2019 and newer Ford Ranger because they use a smart alternator.

There are a few things you’ll need:

Diagram & Instructions:

dual battery charging diagram

Follow the picture above

Find a location to mount the second battery..

Make a short battery wire (4GA-6GA) from your main starting battery (+) positive to a fuse block.

Make another battery wire (4GA-6GA) from your fuse block to the isolator.

Make another battery wire (4GA-6GA) from the other side of your isolator to the other fuse block.

Make a short battery wire (4GA-6GA) from the other fuse block to your other battery (+) positive.

Make a single battery wire (4GA-6GA) from the (-) negative on your starting battery to the (-) negative on your other battery.

Connect a 12GA wire from pin on the isolator to a fuse in your fuse box that is only ‘hot’ when the key is in the ‘ON’ position.

About The Author

Founder / Administrator at  | Staff Profile

Jim Oaks is the founder of TheRangerStation.com, the longest-running Ford Ranger resource online since 1999. With over 25 years of hands-on experience building and modifying Ford Rangers — including magazine-featured builds like Project Transformer — Jim has become one of the most trusted authorities in the Ford Ranger off-road and enthusiast space.

Since launching TheRangerStation.com, Jim has documented thousands of real-world Ranger builds, technical repairs, drivetrain swaps, suspension modifications, and off-road adventures contributed by owners worldwide. TheRangerStation.com has been referenced in print, video and online by enthusiasts, mechanics, and off-road builders looking for practical, and experience-based information.