I got old Toshiba 100CS for a good price. After some inspection, I noticed that AutoResume backup battery and RTC battery are already gone bad, and seems can't hold charge. I've checked eBay for replacements, but only got 2.4V RTC batteries. (I don't bother about main battery because I'm gonna use AC power only.)

Battery name Material Output voltage Capacity
Main battery Nickel Metal Hydride 12 V 2600 mAh
Backup battery Nickel Metal Hydride 7.2 V 110 mAh
RTC battery Nickel Metal Hydride 3.6 V 30 mAh

So, it seems that these are just plain Ni-MH cells without any circuitry. Therefore, I'm gonna buy some small Ni-MH cells and fabricate one. Is it okay to do this?


1 Answer 1


These NiMH batteries usually have very simple charging circuitry and replacing them with generic 3 or 6 x 1.2V NiMH cells in series will almost certainly be fine. I remember there were even (3.6V) battery packs being sold in the past for just this purpose. As the resulting capacity will be higher than that of the original batteries, they will need more time for their initial charge.

That said, I’m finding plenty of 3.6V rechargeable “button” battery packs online. 7.2V packs are a bit harder to find in small capacities.

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