strange CPS2 board? Advice needed.

okay so I got a bunch of boards recently, all of them hard to find/rare ones. Was going through and changing batteries on the CPS2 boards and when I got to this one I was a little confused. The board is a japanese Choko board, however it has no label and never appeared to, instead it has a sticker with characters that read Chang Jian.

So I opened up the case and was greeted by the PCB which had 6 memory (SIMM) slots, 3 of which were populated. I snapped some pics of them *below*

I dont know if this is even that strange for this board but I have never seen a CPS2 board with memory modules in it. My biggest question though is it safe to yank the battery and put a fresh one in. Chances are yes, but I figured I would ask first as I would be pretty irritated if I lost this board.

Anyways, heres the pics

thanks for the help!

http://img403.imageshack.us/img403/9563/choko1ip3.jpg
http://img144.imageshack.us/img144/2293/choko2dg0.jpg
http://img529.imageshack.us/img529/8370/choko3ew1.jpg
http://img403.imageshack.us/img403/3185/choko4pm6.jpg

It's OK. Some later boards (Pro Gear for instance) are like that. The battery is the same as any other CPS2.

thanks MKL! Much appreciated.