Not having any NiCd cells handy, but having a disused set of 10 tabbed 2300 mA NiMh AA cells soldered in series and just lying around from a failed attempt to re-cell a Duo battery (the failure led me to use 4/5AA cells in the next attempt), I separated the cells and temporarily wired 5 NiMh cells into the 1xx battery pack, along with the little thermal thingie from the Duo pack (as it was already there between the cells, and as I happen to be watching the thing all the time it is plugged in).
All tests done on a PowerBook 150. Yes, I know, but alas, I do not own a 180.
The NiMh cells, truth be told, had been tortured to within an inch of their life by a soldering iron in my original attempts to re-cell that Duo battery, largely because I found it impossible to fit the ruddy things in there over several attempts, and then they had been left unused for about 18 months. The first couple of cycles went as follows, and more or less exactly as Wally had speculated: "full charge" was reached within about 3 mins, and full discharge within 60-90 seconds. Before going to bed, I charged the battery up again and then left the machine asleep on battery power overnight.
It was still alive in the morning, but on waking, it shut down immediately through lack of power. I plugged it in and rebooted with mains power, and the battery this time charged for a good 2 1/2 hrs, and gave me about 45 mins. of runtime. I did this while running Battery Amnesia (which cranks everything up to full power - avoiding any screen dimming and the like), which drained the cells again until the machine shut down. It then charged for another 2 1/2 hours and I am in the midst of cycling the battery again. So far, it looks about the same as last, but we'll see. It would be normal to expect that NiMh cells would improve with a few cycles.
It strikes me that if this works, then Shangri-La is at hand, as it would be possible to glue in a couple of AA battery trays (a 3 and a 2) wired in series and then simply pop in standard button AA NiMh cells as required, say a set of 5 at 2800 mA.
The battery plastics, which have to be separated to allow removal of the original cells, could be left unglued (as in my jury-rigged main battery at present), as the PowerBook itself holds the arrangement together without any trouble. Use of standard battery trays would also obviate any problems that might result from having NiMh cells shaking around in an otherwise half-empty battery pack — not a good idea in terms of keeping them soldered together, but more importantly, representing a considerable fire hazard.
However, I haven't gotten that far yet. Counsel is still welcome. E.g., I see from searching this Board that opinions differ on whether NiMh batteries can be substituted for NiCd cells, and so, just for the present, I don't think I will leave it plugged in unattended.
All tests done on a PowerBook 150. Yes, I know, but alas, I do not own a 180.
The NiMh cells, truth be told, had been tortured to within an inch of their life by a soldering iron in my original attempts to re-cell that Duo battery, largely because I found it impossible to fit the ruddy things in there over several attempts, and then they had been left unused for about 18 months. The first couple of cycles went as follows, and more or less exactly as Wally had speculated: "full charge" was reached within about 3 mins, and full discharge within 60-90 seconds. Before going to bed, I charged the battery up again and then left the machine asleep on battery power overnight.
It was still alive in the morning, but on waking, it shut down immediately through lack of power. I plugged it in and rebooted with mains power, and the battery this time charged for a good 2 1/2 hrs, and gave me about 45 mins. of runtime. I did this while running Battery Amnesia (which cranks everything up to full power - avoiding any screen dimming and the like), which drained the cells again until the machine shut down. It then charged for another 2 1/2 hours and I am in the midst of cycling the battery again. So far, it looks about the same as last, but we'll see. It would be normal to expect that NiMh cells would improve with a few cycles.
It strikes me that if this works, then Shangri-La is at hand, as it would be possible to glue in a couple of AA battery trays (a 3 and a 2) wired in series and then simply pop in standard button AA NiMh cells as required, say a set of 5 at 2800 mA.
The battery plastics, which have to be separated to allow removal of the original cells, could be left unglued (as in my jury-rigged main battery at present), as the PowerBook itself holds the arrangement together without any trouble. Use of standard battery trays would also obviate any problems that might result from having NiMh cells shaking around in an otherwise half-empty battery pack — not a good idea in terms of keeping them soldered together, but more importantly, representing a considerable fire hazard.
However, I haven't gotten that far yet. Counsel is still welcome. E.g., I see from searching this Board that opinions differ on whether NiMh batteries can be substituted for NiCd cells, and so, just for the present, I don't think I will leave it plugged in unattended.