Replacing Your 12v Battery

FB has some good videos on the process to replace the battery: Part 1 Part 2

Videos on how to slide the old battery out and slide the new one in.

The 12v battery in your FUV is an AGM style battery. This battery is used to power your screen, help start the charging process, and to power other needed processes. If you have ever left your battery without charging for 3 or more days (consecutively) or if you did leave your FUV on a charger but had a power bump that disrupted the charging so that it didn’t charge for 3 or more days (consecutively), then the AGM battery might have problems:

Yellow 12v icon on the dashboard (problem)
Red 12v icon on the dashboard (serious problem)
Touch screen (dashboard) won’t come on when you touch it
Strange behavior when operating with the screen
Won’t charge when on charger - usually with screen that is black and unresponsive
Seems to get fixed (albeit temporarily) if trickle charged and the system is reset

The only way to really know if your battery is bad is to remove it and stress test it at a battery store that has the equipment. But if you ever left the battery to die and had to charge the battery and/or reset the system (using a left or left and right reset), then your AGM battery is now very grumpy and likely not trusty. AGMs do not like to ever be drug down in charge, doing so can permanently ruin it.

Steps to Replacing the 12v battery

In addition to the videos above, here are some written steps you can take:

Remove the negative connection on the left side of the battery, then the positive on the right.
The aluminum bracket that the fuse panel is mounted to is the retainer bracket for the battery. Look to the left of the panel from the other side of the frame tube, and you can see the left side bracket bolt, which also has the ground strap that goes to the battery. Remove the bolt.
There is a matching bolt on the other side. Remove the bolt.
There is a third bolt (at the same depth) in the middle above the battery. Remove that last third bolt.
Lift the bracket with the fuse panel still on it, and slide out the battery from the bottom.

Where is the 12v battery?

The 12v battery is located on the left side of the driver, near the knee. Hard to get to, but definitely serviceable. It is small and absolutely needed to operate the vehicle. If it starts going bad, many people are replacing their 12v batteries AGM batteries with Lithium Ion type 12v batteries. The process of replacement can be difficult for people that aren’t handy or mechanically inclined. But it is doable. I would suggest finding a mechanically competent person to help you if you aren’t in that category.

To trickle charge the 12v battery and find its location, refer to the FUV Maintenance Quick Reference Guide starting around page 19.

A lithium ion 12v battery is superior to the stock AGM battery because many lithium ion batteries have a built in BMS - Battery Management System. This is a small computer within the 12v battery that doesn’t allow the FUV to draw the battery down or over charge, thus protecting it. The FUV does have a BMS, but it is for the larger HV (high voltage) battery that is located in the tunnel, below the seats. While your FUV is off, it is still drawing power from the 12v battery so that it can respond to the touch system and other on going systems. So if you are not actively driving your FUV or charging it, the 12v battery is not getting any charge but instead drawing down daily.

And this is why daily charging is, for the most part, highly, highly recommended.

If you find your 12v battery is dying, replacing it with a lithium ion battery isn’t a bad idea.