The Art Of CPS2 Battery Maintenance

Written by Tormod Tjaberg

Last update: 2006-06-27

image of battery holder with retainer


This project is for owners of the Capcom CPS2 units who want to change their batteries in a simple and elegant manner.

To combat bootleggers, Capcom used encryption in their CPS2 based arcade hardware. The decryption key itself is stored in battery backed RAM. When the battery dies, the game will no longer work. Therefore it's important to change battery every 5-6 years to prevent the board from commiting suicide.

Changing the battery is straightforward but requires a bit of soldering. A much better method is to mount a battery holder instead. That way the next time you need to change battery, you can do it in 10 seconds! [after you have opened the case that is]

I had seen holders for the 1/2 AA batteries before, but it was not until MKL (shmups forum) showed me the Keystone holders with retainers that things became interesting. The retainers prevent the battery from being dislodged!


Battery Holder Image Battery Image Battery Retainer Image



I take no responsibility whatsoever for any damage you might cause to your hardware, yourself or your surroundings when attempting this project. Lithium is a hazardous substance and must be treated with respect. Furthermore I do not perform this service.



Time is of the essence here so prepare and lay out everything you need, before you start the procedure.

Open the CPS2 B-Board using the Torx 20 security bit. Remove the PCB and put it down on an antistatic flat surface.

Look at the Keystone battery holder. There is a small alignment tap underneath, near the + terminal. Remove it with the paper knife so the surface becomes level.

Make sure the drill and drill bit is ready.

I do not use a helper battery because I can perform this procedure in around 6 minutes. Normally the board will survive without a battery for at least 40 minutes but this varies. If you are unsure about your ability to perform this procedure within the time limit, I strongly advise you to use a helper battery.


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