Help identifying a battery

[Antti]

I have a Gigatron MiniMax 1.8 in my A500. It has been working fine until yesterday, when I noticed that it doesn't keep track of time anymore when the PSU is switched off. The RAM board has a white barrel type battery with "JAPAN 8508" printed on it. The closest match Google gave me was "SR8508" which is a 1.5V battery. I measured the old battery voltage to be 1.35V. So can anyone confirm that I need an SR8508 replacement battery?

[RedskullDC]

Hi Antti,

Originally Posted by Antti

I have a Gigatron MiniMax 1.8 in my A500. It has been working fine until yesterday, when I noticed that it doesn't keep track of time anymore when the PSU is switched off. The RAM board has a white barrel type battery with "JAPAN 8508" printed on it. The closest match Google gave me was "SR8508" which is a 1.5V battery. I measured the old battery voltage to be 1.35V. So can anyone confirm that I need an SR8508 replacement battery?

Definitely won't be a 1.5V battery.

Looking at a hires scan of the card from:
http://amiga.resource.cx/photos/phot...ax&pg=1&res=hi
It uses the normal OKI MSM6242 RTC chip, which requires at least a 2.0v backup voltage to maintain the time.

RTC chip docs can be found here:
http://www.alldatasheet.com/datashee.../MSM6242B.html

The battery area on the scan above looks like it will take several different capacity NiCD/NiMH, 3 pin, 3.6V type cells.
Something like:
http://www.jaycar.com.au/productView.asp?ID=SB1612

Hope this helps,
Red

[chiark]

Googling for 8508 battery gives results pointing to 3.6v nicd batteries...

[Antti]

@RedskullDC: I'll get one of those 3.6V batteries and see if they work. Thank you!

@chiark: All I get is FT-8508 which is meant for Toshiba cordless telephones. Thanks anyway.