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PowerBook 500 Series Battery Rebuild Failure (Oops, all dead EMMs!)
- Thread starter 3lectr1cPPC
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Very weird then how these both do about 40 minutes each. I have no clue what’s up with that.
The first pack has no errors in the memory, second one has a single uncorrectable error but still works seemingly as expected (aside from the low runtime)
The first pack has no errors in the memory, second one has a single uncorrectable error but still works seemingly as expected (aside from the low runtime)
And this is with a stock charger or a custom one with only 1A on vbatt? I was getting premature charge stop with my 2A charger due to overheating and that’s when I saw poor performance. I ended up watching empathy charging the pack and noticed it stopped when the reported temp went over 50C (I think it was 50C - mentioned it in one of my earlier posts). I was able to get better charging after moving to 1A charging.
This is the 15V 1A supply that you (or someone) recommended for VBATT.
It jumps from something to 100%, and similarly will drop from some % to 0 when discharging. I just don’t know why I’d be having the same problem with both batteries - I don’t remember the exact temp when it jumps to 100, but I don’t think it was too warm.
Yeah that is weird. That jumping probably does mean it’s not fully charging the battery. Even though the battery isn’t hot, curious if the temp sensor is bad (but how come on both). My batteries behaved similarly during incomplete charge. When fully charged (or when I think it’s received a good charge) I usually see a battery amnesia graph like what @croissantking showed, cept mine was more ‘S’ like instead of the abrupt sharp transition to a horizontal flat line in the middle of the discharge like what @croissantking had. On bad charges I saw a linear and steep line down to 0 or a very sharp drop down to 0.
Now I am also curious whether there’s strange behavior of battery amnesia that we don’t understand. I would think the discharge rate should be steady and battery amnesia is supposed to drain the battery quickly. The fact that some of our graphs are showing a middle section where it almost stops discharging is weird. Perhaps a 40 min discharge in battery amnesia is correct and a longer discharge time like my 80-100 mins and @croissantking’s 200 mins is something going on with battery amnesia where for some reason it stops discharging or does it very slowly?
Now I am also curious whether there’s strange behavior of battery amnesia that we don’t understand. I would think the discharge rate should be steady and battery amnesia is supposed to drain the battery quickly. The fact that some of our graphs are showing a middle section where it almost stops discharging is weird. Perhaps a 40 min discharge in battery amnesia is correct and a longer discharge time like my 80-100 mins and @croissantking’s 200 mins is something going on with battery amnesia where for some reason it stops discharging or does it very slowly?
Yep, I’m impressed too!
It’s a long thread now, this one, and while I’ve tried to read everything, I’m sorry, I’ve lost track of which cells you’re using in your 200-minute battery - could you tell us again, please?
Oh, I missed this. My A size cells are labelled HT2 KA17, made by Vapex-Tech.
That’s 200min for two batteries, not one!
For me that’s when the switchover from one battery to the other happens.
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Oh!!! I thought that was for one. Ok so then we are getting similar capacity.
I see. I was seeing an S curve with a single battery. Drains fast, starts slowing down, then starts speeding up again at the end. Never flat but a sideways S curve.
Thanks!
I got a cheap deal on Eneloop Pro AAs (which I identified as being able to accept a 1A charge rate easily) and swapped that memory chip that I’d ordered. And thanks to jmacz identifying the need for that, it produced a battery pack that actually ‘repaired’ properly with Lind - I was amazed.
The performance of the resulting battery isn’t amazing at 67 minutes in Battery Amnesia, but I’m happy with it. The tricky part is remembering to keep it charged/exercised, and hopefully the long-standby nature of the Eneloops should help with that.
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I check my laptops every few weeks to ensure the batteries haven't gone down to 0V. Found my 540c wouldn't boot last night. My Sanyo "A" pack was down to 0. But the pack was fine and it recharged and it's holding charge.
My "AA" pack however is not responding. It's not detected in either battery bay and EMMpathy/LIND both can't see it.
My multimeter shows a healthy voltage (11.1V) but something's going on with it. One of the two pads is reading 5V and matches what my working battery reads. The other pad however is reading 5.4V whereas my working battery reads near 0. I think this is the data pad. Not sure why it's at a constant 5.4V. Unfortunately resealed the plastic on these batteries so I'll need to cut it open again to figure out what's going on inside.
My "AA" pack however is not responding. It's not detected in either battery bay and EMMpathy/LIND both can't see it.
My multimeter shows a healthy voltage (11.1V) but something's going on with it. One of the two pads is reading 5V and matches what my working battery reads. The other pad however is reading 5.4V whereas my working battery reads near 0. I think this is the data pad. Not sure why it's at a constant 5.4V. Unfortunately resealed the plastic on these batteries so I'll need to cut it open again to figure out what's going on inside.
Our stars are sort-of aligned, because meanwhile yesterday here in NZ I realised my 540c battery, made with Eneloop AA cells about six months ago, has stopped working (although the BMS was responding normally, and then reporting a shorted cell).
I opened it to find this great disappointment. Not sure what I’ll try next (almost can’t be bothered) but sounds like I need Sanyo ‘A’ cells too!
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I had a rebuilt battery that kicked the can, too. Turns out the EMM board just died. I moved the battery pack into another donor battery shell.
Thanks, both of you, for keeping this thread and the good intentions alive I look forward to deciding which cells to try next, but it does feel like batteries for old machines are a liability and not worth the trouble and expense… I guess my mistake was leaving it fully inserted in the 540c, I thought the battery would be clever enough not to drain itself fully
I look forward to deciding which cells to try next, but it does feel like batteries for old machines are a liability and not worth the trouble and expense… I guess my mistake was leaving it fully inserted in the 540c, I thought the battery would be clever enough not to drain itself fully
Thanks, both of you, for keeping this thread and the good intentions alive
Sure, my 500 series machines are very prized, so am interested in their upkeep!
I'm shocked that your almost-brand new cells leaked. Is leaving them discharged the likely cause?
Thanks, both of you, for keeping this thread and the good intentions alive
Yeah, they are a hassle .. but I can’t let go of the portability
I also leave them in but check them every few weeks. I probably should leave them out but even then, I think the EMM still consumes energy so it’s still an issue.
I took apart my battery. Everything looks fine inside but the EMM is acting very different from my others and so I think the EMM is shot.
I have two spares left and so am using one of them to rebuild. Just finishing up closing it up to test.
It's clear to me at this point that the EMM is a very poorly designed BMS. Drains the cells flat on its own, constantly produces EEPROM errors such that there are two aftermarket tools to fix this, and on top of all that seemingly just likes to drop totally dead. I had one do the same thing (way back at the start of this thread).
These 500 batteries have got to be up in the "terrible BMS hall of fame", right next to the IBM ThinkPad 600 battery...
These 500 batteries have got to be up in the "terrible BMS hall of fame", right next to the IBM ThinkPad 600 battery...
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