Introduction: How to Change Game Boy Cartridge Battery

About: I'm an amateur DIY-er, but thoroughly enjoy new concepts and ways of creating new things or just amping up old things. I almost always forget to document the projects I work on, but when I do I love posting th…

Do you have an original Game Boy (GB) game, or a Game Boy Color (GBC) game? One that you've spent days of play time on, won so many achievements with, or just can't part with the saves you have on there? If so, it's more than likely (almost guaranteed) that there is a battery inside that old game cartridge, and if it's never been replaced, is finally going dead. And that means bye-bye saves!

So with that morbid news, what do you do now? Well, that's what this Instructable is for!

After many searches of Google, and some questionable posts by questionable people, I ran into several ways to be able to replace that decrepit battery in the cartridge that is loved so dearly without losing the savestate, but they were somewhat vague and not really what I was looking for. So after seeing these things, I thought to myself that there's got to be a better way, and figured "What the heck? Why not give it a try?"

And surprisingly, it works!

So if you're ready to replace the battery in your Pokemon game or Wario Land cartridge without losing the precious saves, then read on!

NOTE: Pokemon, GB, GBC, GBA/GBA SP, Nintendo, etc. do not belong to me (clearly, otherwise I'd be rolling in mountains of cash). In no way do I claim ownership to these things.

NOTE #2: This project is of your own doing. I am in no way responsible for any problems that may occur in doing this procedure. So that means you can't sue me. I think.

***EDIT NOTE: jmetal881 was nice enough to point out in the comments that it's not a good idea to solder the battery to the tabs because of the heat (it could potentially melt the battery). Just be aware of the dangers that could happen if you do solder the battery! Also, as an extra emphasis, DO NOT TOUCH ANY OF THE CIRCUITS OR BATTERIES WITH ANYTHING METAL WHILE DOING THIS! ALWAYS COVER YOUR TOOLS! Or else death awaits your precious game! :)

Step 1: Note to Pokemon Players

I wanted to put here some things I've found with my Pokemon game that I thought would be useful for others.

The reason I needed to change the battery in my cartridge was because the time in my Pokemon Crystal game wasn't advancing with real-time. It would save at Thursday 8:30AM, then when I came back a day later it would resume at Thursday 8:30AM rather than Friday 11:17AM or whatever; yet I could still save and load just fine.

So for Pokemon people that's usually a tell-tale sign the battery is going. Usually the clock goes out first, so if you find that you had my issue or if it constantly asks you to reset the time, that means it's time to change the battery.

However, if you find that your save state is already lost or you just received the game and want to replace the battery, then follow these instructions but without putting the game in the GBC or GBA; just change the battery outside and by itself. It's so much easier than trying to change the battery while keeping the saves.

Step 2: Materials Needed

Here's the list of things you'll be needing for this fabulous life-saving project:

1. The game (Pokemon Crystal is used for this Instructable)

2. A game system with an open back that can play GB games

-The reason for the open back is so you have room to work on the game. I'd recommend either an original GBA or an SP if you have one, but if not then use the GB or GBC.

3. The new battery

- GB games take CR2025, but some say you can use other sizes. I haven't tried any others than the CR2025 so use at own risk! Also, it appears that the manufacturers use Maxell batteries (mine did), and mine lasted almost 14 years. So I guess if you want long life get a Maxell! [Unfortunately I found that out too late so I just used my Duracell]

4. Pair of small needle-nosed pliers

- This is for opening the game cartridge and other things, but if you have the bit that can open the game, then by all means use that!

5. Some flathead screwdrivers and possibly some picking tools

- These are mostly for prying the manufactured battery off the prongs that hold it in.

6. Soldering iron & some solder

- This is just in case the prongs that hold in the battery pop off (mine did), and also if you want to solder the battery in instead of taping it in. If you do, get a soft solder so it's easy to melt and break for later changing (in about 9 years).

7. Some non-conductive tape

- This is if you prefer to hold the battery in with tape and don't want to risk the possibility of messing up something with the solder (which is what I did, but might change sometime in the future). It's also for covering metal tools.

8. Common sense!

- This is a must!

***EDIT NOTE: One other part you can opt to get is a brand new replacement battery. This way you can circumvent the whole taping and bending the prongs just right. You can get a single one here or 10 of them here (for extra security!).

Step 3: Quick Check Before Getting Started

It's always a good idea to take the game and make sure it still has your saves. So put it in and boot it up!

Step 4: Opening the Cartridge

Okay, this is the easy part.

First get your cartridge and flip it over. Grab your needle-nose pliers (or your screwdriver with the special bit in it) and as gently as possibly remove the screw without stripping it.

For those of you who don't know what that means, stripping a screw is when you repeatedly chip away the metal on the screw head, making it almost impossible to use it again. For example, if you had a philips head screw (a plus-shaped indent) and the head was strippied, the indent would look more like a square than a philips head; making it hard to use it again.

Now these things are a bit weird. You can't just pull it off after you unscrew it. You need to flip it back over and take the cover and pull down, then off (see pictures). And viola! 'Tis open! And low and behold, 'tis the doomed battery!

Step 5: Prepping & Loading the Game

This is really important! Make sure to pay close attention to these next two steps!

For this you'll need the game system of your choice and the opened game cartridge. Here I'm using a GBA SP because it has much more work room then the GBC or GB. I didn't have an original Game Boy Advance to do this with, but I'm sure it has enough room to work on the game.

Take the cartridge (with the back and board together) and put it in the slot of the GBA (or whatever you're using). Be gentle with it and turn the system on. Make sure the game loads smoothly and no freezing occurs. If it won't load at first, jiggle it a little. It shouldn't be an issue though, and if it is, you may be in for a really tough time trying to save that savestate.

The reason for this part is because the battery in the cartridge is what keeps the savestate and (in the Pokemon games) the clock going. If the battery is unplugged or dies, the savestate stored in the SRAM (which is the game's memory) will be deleted. To circumvent that, we plug the game into the system and turn it on. This gives power to the board and allows us to remove the battery without the SRAM turning off and thus destroying the save file.

I'd recommend booting up the save or going to a place in the game where there is constant music playing without a break. In my game (Pokemon Crystal), I loaded my save and went to the Pokemon Center which has constant music playing.

The reason for this is so you know if the game freezes during working on the battery. When it freezes, the music stops or plays a continuous note. The reason on Pokemon Crystal I didn't just leave it on the title screen was because there's lots of pauses and fades, which would be unuseful in this case.

Step 6: Changing the Battery (with Skill!)


Through this whole procedure, make sure to have a steady grip on the cartridge; making sure it moves as little as possible.

Okay, so the manufacturer's battery has about a total of five solder points. Some older games may have more or less; just be prepared to do some yanking!

To remove the battery there's several options. You can try to de-solder the battery if you're confident in your abilities; or you can as gently as possible break the solder with various tools. I did the latter because mine wouldn't de-solder.

I used a very small flathead to pry up the top prong so I could get a better grip with the pliers.

Several tips: When dealing with the battery (and no other piece of the board) you can use un-covered tools. However, when you start working on the bottom prong of the battery, use covered tools. When I say covered, I mean putting a layer of tape over the section of the tool that could come in contact with any other part of the board.

The reason being that if at any point you accidentally slip and touch any of the circuits on the board it will short the game and cause it to freeze. Now it won't destroy the game (unless you actually destroyed the circuit), but if the game does freeze (before you removed the battery) you should be able to just restart it up and continue working.

Just in case you were unaware, the point of this step is to remove the battery with as little destruction as possible.

I can't really say what to do exactly because each game is different (or so I am told), so try to do what you can without injuring the game.

If the prong pops off, no worries! Just solder it back on!

Make sure to continually listen to the game while working to see if it froze. When you finally remove the battery, give it a quick double-check and make sure the game is still on and working. Also, take note as to where the positive and negative go, as you'll need to put the new battery in the same way.

Step 7: Putting in the New Battery

This step is relatively easy.

Get out the new battery and pop it in there the way the old one went in (mine was positive side down). You can either solder it in or use tape if you're afraid to mess things up or are afraid of having to wrestle with the solder the next time you change it. That shouldn't be a problem though if you use a soft solder which would be easy to break. You just need something to be able to keep it from moving and keep the contacts on the battery at all times.

If you do solder it in, solder the prongs to the battery, bottom first and then the top. DO NOT SOLDER THE BATTERY TO THE BOARD! Let the solder cool just in case it might burn something.

As a side note, these things are pretty resilient. I accidentally dropped some solder on one of the larger chips on the cartridge thinking I ruined it; but it ended up just falling off after it cooled and didn't affect the game at all.

Step 8: Putting It Back Together and Running the Final Check

The moment of truth!

Once you have the battery secured (and are sure that it is), turn off the system and unplug the game.

Put the cover back on and screw it back together.

Put the game back in, cross your fingers and turn it on.

YAY! You did it! You just changed the battery and kept the save all by yourself and without troubles!

Take a moment to step back and admire your handy work. Bask in the glory, and gloat about your electronics prowess to your fellow cubicle dwellers!

Now grab a nice tall glass of lemonade and play that sucker 'til the sun goes down!

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