Thinkpads Forum

Just wondering if anyone knows if there's a "proper" way to charge a new CMOS battery. I picked up 2 new VL2020 batteries from a reseller I found online for my 755C and 360CE, and also 2 CR2020's for my 755CE and 760ED.

Anyways, these batteries are different from CR2032/CR2025, in that they are rechargeable 3V batteries.
So I'm wondering if I need to keep the system powered on to have it recharge? I popped one in there, left the system plugged in but off, but I still got a 161/163 code when I powered back on. Obviously, I'd like it to work so I don't have to enter the time and reconfigure settings every time I want to use the computer.

Try running that machine for a few hours (with the screen set to darkest or off).

RealBlackStuff wrote:Try running that machine for a few hours (with the screen set to darkest or off).

I tried that, but the battery didn't seem to hold a charge beyond a few days. I took the standby battery out (NiCd) because I don't want it to leak. Same for the main battery. Not sure if those are needed or not, but the HMM didn't have any specifics.

Similar to drill batteries, you could probably replace the NiCd with NiMh.

I have an old B&D drill from last century (!) that is still running with its original 9.6V battery, 1.7A, NiCd.
I get about 10-15 minutes usable time out of it (can take weeks before the battery is empty when used sparingly).
Today I'm expecting a 9.6V, 3.0A, NiMh replacement: http://www.ebay.com/itm/400857608093
Dewalt uses the same battery design as my old B&D.
After reading up on it, NiMh should improve battery life considerably, when compared with NiCd.

I've only worked on a 701C and a fewTransnotes, then nothing till A22m, T23 and up.
So can't help you any further.

Same problem with my 755C. Put in the VL2020, charged up and still get bios reset every boot. The main battery is dead but the TP will not boot without it in situ and with the switch set to 1.

RealBlackStuff wrote:Similar to drill batteries, you could probably replace the NiCd with NiMh.

I have an old B&D drill from last century (!) that is still running with its original 9.6V battery, 1.7A, NiCd.
I get about 10-15 minutes usable time out of it (can take weeks before the battery is empty when used sparingly).
Today I'm expecting a 9.6V, 3.0A, NiMh replacement: http://www.ebay.com/itm/400857608093
Dewalt uses the same battery design as my old B&D.
After reading up on it, NiMh should improve battery life considerably, when compared with NiCd.

I've only worked on a 701C and a fewTransnotes, then nothing till A22m, T23 and up.
So can't help you any further.

I did some research, and the standby batteries are either GB60H or 60K. Anyways, GB60K does show up in a google search:

http://www.qualitechbattery.com/shopima ... 121838.pdf

I might try and get the NiMH version, since we all know it's better than NiCd, and for the most part, interchangeable. I'm thinking of investing in a spot welder from ebay, as I have several batteries I'd like to rebuild. Obviously, the standby battery doesn't make a difference unless the primary battery works. I got another 360CE today from ebay, and amazingly, the battery actually holds a charge (aftermarket Xtend brand, which, sadly, is no longer available).

StevieD wrote:Same problem with my 755C. Put in the VL2020, charged up and still get bios reset every boot. The main battery is dead but the TP will not boot without it in situ and with the switch set to 1.

I ordered supposedly new ones from microbattery.com, out of Miami. Ended up checking with my Fluke multimeter and sure enough, the batteries were discharged enough that they were probably toast. So the company is sending me new ones and 2 extra ones for free for my trouble.

I still wonder how long the system needs to be powered on (or plugged in) for it to have a full charge, as the VL2020 is actually a rechargeable battery.