[FC] How to replace the built-in battery in a Famicom cartridge (including solderless methods)

Is anyone having trouble saving Famicom games or having their saved data disappear immediately?
The most common cause of this is a dead internal battery for saving.
The term "built-in battery" may sound difficult, but it's actually quite easy to replace.
In this article, we will show you how to replace the built-in battery in a Famicom software.

*If you fail to replace the internal battery, it may result in damage to the game cartridge. Please do so at your own risk.

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Tools required for replacing FC soft batteries

The tools required to replace the built-in battery in a Famicom game are as follows:

All of these are easily available through online shopping.

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FC soft battery replacement procedure

The procedure for replacing the built-in battery in a Famicom software is as follows.

Now let's explain each step.

Open the FC cassette

No screws are used to secure the Famicom cartridge.
Insert a flathead screwdriver or parts separator into the gap at the bottom of the cassette and pry it open.

I was able to open the cassette.
But for fixingOne of the claws broke...
The plastic in Famicom cartridges tends to crack over time, and the tabs can easily break, as in this case.
It is difficult to open it without damaging it, so please understand this before proceeding.

Remove the old battery from the FC software

Once you've opened the cassette, remove the old battery from the circuit board.

The battery pins are soldered to the back of the board, so remove them to remove it.

Use a solder wick or similar to remove it.

I was able to remove the old battery.

Install a new battery in the FC software

Place the new battery where you removed the old one.
One thing to be careful about is not to get the positive and negative terminals of the batteries mixed up.

Restore the FC software

Once you get this far, the rest is easy.
Place the board in the cassette and close the lid to complete the job.
Let's check if it works properly.

When installing the battery holder

It is also possible to install the battery holder in the same way as installing the battery so far.
You may want to consider installing a battery holder, as this will make it easier to remove the button battery and allow you to use your preferred button battery.

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Solderless FC software built-in battery replacement procedure

Here's how to replace the battery in a Famicom cartridge without soldering.
For information on how to open the cassette, please refer to the same section in the replacement procedure using solder mentioned above.

Remove the old battery from the FC software

The soldering method required removing the entire pin of the built-in battery, but this method only removes the battery itself, leaving the pin in place.
The pin is attached to the battery, so remove it using a flathead screwdriver.
Be careful not to scratch the battery or surrounding circuit board.

The pins are on the top and bottom of the battery, so remove both.

I was able to remove the battery.
This is a harder task than it looks, so try it when you're motivated.

Install a new battery in the FC software

Once you have removed the old battery, insert the new battery into the pins.

Just wrap it around with cellophane tape or vinyl tape and secure it firmly!
Be careful not to mix up the positive and negative sides of the battery.

All that's left to do is put the cassette back in place and you're done.

FC software is prone to breaking due to aging

This time, we have introduced how to replace the built-in battery of FC software.
Since all of the software has been on the market for quite some time, they have become more fragile due to aging and the solder has become harder to melt, so you need to be careful when working with them to avoid damaging them.
Avoid taking on the reckless challenge of suddenly changing the battery in premium software, and instead practice with software that you won't mind failing.

*2022/10/20 Added information about the battery holder