gsteemso
Well-known member
Hi all, I looked through the archives here for any mention of 500-series PRAM batteries (it turns out that they are actually full-on 50-mAh backup batteries, not just a feeble thing for for keeping the PRAM alive), and apart from learning that they are very unlikely to leak or to stop working entirely as they are non-exploding rechargeables, the only things I was able to determine were: (1) they are physically very difficult to access if you do want to replace one, and (2) you cannot get one to charge in-circuit without first persuading the PowerBook that its main battery has charged up as far as reaching working voltage.
That latter point is damned awkward. I was lucky enough to receive two main batteries with my 540c, but as is usual for such at this point in history, both are stone dead. Recelling them would not be particularly difficult, but they are (at least nominally) “intelligent,” and the embedded microcontroller is not a known quantity as far as getting it to accept that its notions of prior charge behaviour need to be forgotten about.
Does anyone have any tricks for either (a) fooling the machine into charging the backup battery in the absence of main batteries, and/or ( B) getting the main batteries to resume working after recelling? I will be very surprised if I ever am able to operate the unit on battery power for longer than a couple of minutes. I am not convinced that will ever really be an option and am not worried about it; I just want the backup battery to be useful again.
That latter point is damned awkward. I was lucky enough to receive two main batteries with my 540c, but as is usual for such at this point in history, both are stone dead. Recelling them would not be particularly difficult, but they are (at least nominally) “intelligent,” and the embedded microcontroller is not a known quantity as far as getting it to accept that its notions of prior charge behaviour need to be forgotten about.
Does anyone have any tricks for either (a) fooling the machine into charging the backup battery in the absence of main batteries, and/or ( B) getting the main batteries to resume working after recelling? I will be very surprised if I ever am able to operate the unit on battery power for longer than a couple of minutes. I am not convinced that will ever really be an option and am not worried about it; I just want the backup battery to be useful again.