replacing back-up batteries

[noobish hat]

anyone have any tips on replacing dead battery back-ups in original gameboy cartridges? e.g. which drivers to use, what type of battery etc
i've gone and bought an original jap link's awakening but the battery's long since bitten the dust
thanks!

[MattyD]

I've just done a Pokemon cart for my wife and it was actually quite easy.

Things you'll need:

• a Gamebit screwdriver heads (the smaller one, which I think is the 3.8mm). P-A seem to be out of stock so you might need to buy one from someone here, or there's an outside chance you'll be able to get one in Maplins or somewhere like that as they've started stocking non-standard screwdrivers like tri-wings for mobile phones etc.
• a small, flat headed precision screwdriver
• a replacement battery. Don't pay silly money for one in a watch shop, got to Maplins or order one from their catalogue, they're like a pound fifty or so there. The model you'll need is a CR2025.
• some sticky tape

Here's how it's done:

1. Remove the single screw in the back of the case using the Game Bit.
2. Hold the cart between forefinger and thumb and slide the sticker side upwards from the back half. It'll move a little and then can be taken off.
3. Tip the remaining half of the cart so that the PCB inside falls out, preferably into your waiting hand
4. You'll see the battery on the upper right of the PCB, held down by some small metal tabs. These are soldered to the battery and since using a soldering iron on a battery is a definate no-no, we'll be using the flathead screwdriver to chisel it off. Look for a little divot or nub - that's the joint - and gently tap horizontally against it, along the surface of the battery. A few gentle taps should break the joint. Now gently bend the tab back out of the way but don't remove it from the board.
5. Once the upper tab has been disconnected, *gently* pull the battery away from the PCB so that the underside tab is exposed, and break the joins there as well so that the battery can be removed. Once again, be careful to only remove the battery and don't break the tab off the PCB.
6. Now, using a pre-cut length of sticky tape about 15cms long, hold the new battery against the bottom tab, ensuring the correct polarity (the + side with all the writing on goes face down) and stick apply the edge of one side of the tap to stick them together. Make sure the stuck edge is at the top with the rest flowing downwards towards the cart pins, this is important later on.
7. Lower the battery enough to press the upper tab onto the upper side of the battery, and wrap the tape tightly around so that the tape is now holding both tabs against the new battery.
8. Feed the edge of the tape through the small gap you should have between the battery and board surface, and keep winding until all but about 1.5cms of the tape has been wound around it.
9. Using the last little bit of the tape, which should be coming OVER the battery towards the top of the board, stick the last part to the edge and fold it over onto the back (where there should be a small green area without any tracks in).
10. Enjoy!

There's a guide with pictures here to give you some idea of what you'll be looking at before you go doing it.

If you don't like the sound of doing it yourself you could send it to me and I'll fit a new one for you. It takes no more than a couple of minutes.

[chaoticjelly]

I've got some 3.8mm Gamebits mate.

Make sure you get the replacement battery with tags.

You can heat the solder covering the battery tabs to remove the battery, as long as you don't heat too much - I do it all the time and I've never had a battery explode yet.

Just heat the hole whilst gently prising the battery up with a small screwdriver - probably the quickest and easiest way to remove..

Obviously lithium is a fairly volatile substance though so be careful, lol. Allthough lithium explosion burns could be a good way of getting out of doing your paper for a bit

[MattyD]

Where do you buy the batteries with the tabs already on them? The only place I could find was US based and I didn't want to pay the shipping.

[chaoticjelly]

Hmm.. I can't remember off hand.. if I manage to dig some out I'll let you know..