JDM to US Battery Conversion

Installed Battery

Batteries have a tendency to be sensitive to environmental changes. Ever notice how your battery usually goes bad in the Spring or Fall? Going from Japan to the US is no less an extreme. Being in Utah, we assumed that the battery would be bad on arrival, but it seemed to be going pretty well.

Knowing batteries tend to go downhill fast, we ordered two adapters that change standard large US battery posts to the small JDM posts. Without these you have to modify the cables, and we really didn’t want to alter things in a way that wasn’t easily reversible if it was possible. You can get those here: https://www.amazon.com/Pencil-Post-Battery-Terminal-Adapter/dp/B07BJHBDTC/. Thanks to Jigs-and-Fixtures on minitrucktalk.com.

We had these on hand knowing it they would come in handy one day, only that day came sooner than expected.

There had been some hints the battery was on its last legs, where the engine under idle would start to have the warning lights flicker on, and a quick rev of the engine would solve it.

A couple of weeks ago we had a massive storm roll through that wasn’t too much different than a tornado, with roofs getting ripped off, signs smashing in the road, and water up to the door. We were out driving when it hit, and the battery started really acting unhappy. Starting became laborious, and just lots of hints that the electricals were being under supplied.

Well, Saturday, when out picking up dinner the battery finally gave it up. Fortunately one of the bus boys was willing to give a quick push to kick start the truck, but the battery was done.

Looking at the Minitrucktalk forum, there are a number of batteries people have used with success. That is a problem as they all look like good options, and so it really needed to be a direct comparison. We took the dead battery into O’Reilly’s and looked at the options. After comparing the Series 26R has its positives, but it is much larger, and the battery holder wouldn’t work well with it. The mower batteries usually have screw terminals, which is undesirable. The Prius battery ends up too expensive.

We really didn’t want to do anything that wasn’t reversible, so that also informed our decision.

In the end the chosen battery was the 151R size suggested by Reese Allen. This is virtually identical dimensions, with just the larger US posts. That is workable though.

To make it work we also picked up two other parts:

The SK8418SS 18″ negative ground cable and…

negative ground wire

The Super Start Marine-Type Universal Terminal.

battery terminal

We would have preferred to buy one piece, but this was what they had to create a new negative ground. If there is one thing you read about on the Sambar batteries, it is how small the negative ground wire is. It is really not sufficient for a lot of applications. This is the original, and it is about half the diameter of the new one, and it is also quite short.

I’m not going to get too into the process of changing out the battery, as it is pretty straightforward. There are a couple of things we noted:

Getting the battery out is pretty easy, disconnecting it is a pain. There is no way to disconnect the terminals while the battery is installed, and the wires aren’t long enough to reach the ground. It became a real balancing act. We ended up using a bucket to keep it high enough that our hands were free to deal with the connectors.

This is why we selected the 18″ negative ground. It means the negative terminal can be connected while on the ground, which is helpful, then place it on the bucket to get the positive in.

We pre-installed the terminal adapter as seen below.

battery terminal

That simplified things.

We also coated the terminals with Battery Terminal Protection Spray. It was probably from Auto Zone.

Battery Terminal Spray

The location of the battery almost makes it more of a Marine environment, so protecting the connectors is more important than ever. Just don’t spray it on the truck body.

Installed Battery

Here it is installed before putting the cover on. We will be looking for a new battery box, most likely, as the bottom is quite pitted with rust.

fully installed battery with cover

Here it is sealed up.

The battery seems to work great, and we would recommend anyone go this direction if you find your Sambar is in need of a battery.

Share and enjoy!

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