Recently I've been getting back into playing old NES games. Zelda II is a game I've never played much & after reading about what an awesome game it actually is and watching gameplay videos on youtube I decided it was time to start the quest. I got one of my old Zelda II carts out & popped it in my nes & it still had games saves, and still saved as well, but..........was I really going to spend hours progressing through the game depending upon a battery dated 02-89 that should have went bad around 94 according to Nintendo, I think not.
Now it was time to decide what method I was going to use to remedy this problem & as with many problems there were a few options. Ultimately the option I chose was to take a CR2032 battery holder out of my first PC from the late 90's since it's just a parts machine now anyways. This way I could easily use any CR2032 battery I needed & easily switch it out in the future if I ever decide to beat the game again.
Step 1: Robbing the CR2032 Battery Holder From Old Computer.
First step was to desolder the battery holder from the computer motherboard. I let my soldering iron get nice and hot & used a desolder pump to suck away as much solder as possible as I heated it. Finally I had enough removed so as I could use my needle nose pliers to wiggle the holders tabs off bringing the holder with them.
Step 2: Disassemble the Cartridge.
Second step I used my NES cartridge game bit to remove the 3 screws from the back of the cart exposing the inwards of this electronic master piece.
Step 3: Desoldering & Removing Old Battery & Tabs.
Third step is to get the old battery removed. Note the date on the battery of 02-89. Hard to believe it was still working.Desoldering pump came it quite handy here because there was a pretty good amount of solder holding the tabs in place. Originally I thought of using the tabs and simply trying to pry the battery off the tabs but they seem to be welded in place. I even attempted to slide a knife blade under them acting as a wedge to pop the welds but they would not give & actually buldged the old battery housing out under all the pressure so I saw that this method was not what I wanted anyways. I proceeded to remove as much solder as possible with desoldering pump as I heated it up with my iron. Once I had most of the solder sucked away I used my needle nosed pliers to wiggle the tabs until they broke free of the older & pulled it off the cartridge board.
Step 4: Soldering in the CR2032 Battery Holder.
Fourth step I soldered the - and + wires to the cartridge board & then soldered them to the battery holder tabs. Be sure not to mix up the wires. The cartridge board has the + side clearly marked which the wire soldering to it will run to the tab on the holder that makes contact with the shiny + marked side of the battery that is visible when placed in holder. The bottom of the battery is the negative. I recommend doing this before installing the battery because the solder will heat the battery which could destroy or severely impact it's life. Once I had the holder soldering in place I bent the tabs to the side on the holder & placed it in the cartridge housing making sure all fit good.
Step 5: Install the Battery & Secure It in Place.
Fifth step I figured out exactly where I wanted the holder to be doing a test fit & I then installed my battery. I used the Sunbeam CR2032's which I purchased at dollar tree 2 for a dollar. I thought of gluing the holder in place but since I might need to take the cartridge board out again to clean I decided just using black electrical tape to hold the wires in place would be good enough since the battery holder is large enough that it can't move anyways & it was far less messy than trying to use hot glue or having to wait for another type of glue to dry. I then put my cartridge back together & now it was time to test it out.
Step 6: Success!
I slid the cartridge in & powered on the NES & created my save file. I played the game until I died & then saved. I powered off the console (as I held the reset button as the manual states) & powered it back on & my save was present. Now I'm confident my journey will be well protected for many years to come.