The pokemon sapphire game for game boy advance has an internal battery. If this battery runs down, you lose certain features of the game. The battery is not really meant to be a user replaceable item but if you have a soldering iron and a little soldering experience it isn't too bad. Do be aware though that you have to be a little careful as you can damage the game. If you have worked on circuit boards before it isn't bad but if not, you may wish to practice soldering and desoldering a little on something else first.
You will need:
- tri-wing screwdriver for removing the cover
- CR1616 replacement battery with solder tabs (Batteries Plus carries the battery and will put the solder tabs on for you). Note, it appears that amazon also now carries CR1616 with the tabs on it already.
- soldering iron and a small amount of electrical use (NOT plumbing use) solder
- desoldering wick
- tweezers, needle nose pliers, or a toothpick
- old scissors (you will trim some thin metal so leave your sewing scissors in your sewing table!)
Step 1: Remove Cover
To remove the cover you will find you need a special screwdriver. I used this screwdriver http://www.amazon.com/gp/product/B000S6AG9G from amazon. If that link doesn't make it search for "Tri-wing Screwdriver for Nintendo Wii, Gamecube, Gameboy Advance". I paid about $5 for it.
Cover removal is simple. First take out the screw and then slide the back up relative to the front and they will easily lift apart. You do not need to pry anything. The second picture shows the back and front slid relative to each other.
Step 2: Desolder the Battery
After the first corner is desoldered, heat the 2nd joint with the soldering iron and when the solder melts, just lift the battery off. Again, I used tweezers. Needlenose pliers are also appropriate tools and if you don't have either, you can use your toothpick again.
Note that the top of the battery is labeled as the "-" (minus) terminal and goes to the upper right pad on the board.
Step 3: Prepare the New Battery
The solder tabs (strips of metal) that the battery shop spot welded on for me were fatter than the originals and not shaped the same. It was fairly easy to trim them to size using some scissors for trimming and needle nose pliers for shaping. Also you will want to add a small piece of electrical tape on the right hand edge of the battery to make sure that the top tab won't ever short to the edge of the battery.
Step 4: Prepare the Circuit Board
There are likely blobs (that is the technical term) of solder left on the pads where the old battery was. These should be cleaned up. The right way to do it is use some desoldering braid (also known as desoldering wick). This is some thin wires woven together usually with a chemical in it and when you place it on the solder blob and heat with the tip of the soldering iron it will wick up the solder. You can by the wick at any electronics store and probably also your local Radio Shack. You don't need super clean, just wick up the bulk of it. Also you don't want to keep the iron on the board for a long time or you can soften up the adhesive which holds the copper pad on the board. An appropriate amount of time is just a few seconds (2 or so) after the solder begins to flow.
Step 5: Solder Down the New Battery
Being very careful to not let the battery leads touch other parts of the circuit board (they may not appreciate it), set the battery in place. Carefully solder each of the two joints. After soldering the first joint, wait a bit for it to cool before soldering the second. The reason for the wait is so that you don't disturb the first during cooling which would compromise it somewhat.
After soldering down the battery, there will be some rosin (a.k.a. flux) left on the board near the solder joint. That is the darker gunk in the picture. This should be cleaned off. Some solders use a water washable flux. I used a Q-tip dipped in rubbing alcohol (90% isopropol alcohol) and scrubbed lightly. Make sure you let it dry, however you clean it.
Put the board back in the case, put the lid back on, slide it into place, and put the screw back being careful to not strip the plastic threads.
In Pokemon Sapphire the way you can tell it worked is the "internal battery has run dry" message no longer appears when you start the game.