PowerBook 500 Series Battery Rebuild Failure (Oops, all dead EMMs!)

[jmacz]

Yours doesn’t drop to under 700mAH in capacity though.

Yeah, that is true. EMMpathy is reporting the stock 1752 for them always, never changes.

I will test my AA packs on Battery Amnesia later today... currently running down my new "A" pack.

 

[jmacz]

Just really confusing how all this stuff works

I charged my new "A" pack fully via the PowerBook. EMMpathy showed 100% etc like I mentioned a few posts earlier.

I then launched Battery Amnesia and it reported in it's progress that it was starting at around 49%. Huh? I wonder where it gets that value from but how is it that I charged the battery to what the PB and EMMpathy thought was 100% yet this tool is suggesting it's at 49% unless I am understanding this meter wrong.

What's interesting is that Battery Amnesia has been working on this "A" pack for 50 minutes now, which I guess is good. And the progress meter is at "20% left" right now, voltage reading at 10.15V. So it went from 49% to 20%, and took 50 minutes so far to do that. Let's see how much longer this goes.

 

[3lectr1cPPC]

Batteryamnesia sees each of the 500 Series two packs as 50% each. If you plug a battery into the left bay, it should jump up to 100% according to it.

 

[jmacz]

Batteryamnesia sees each of the 500 Series two packs as 50% each. If you plug a battery into the left bay, it should jump up to 100% according to it.

Ah, that makes sense. 61 minutes now and 15% left with this "A" pack.

 

[jmacz]

Finally died at 88 minutes with the "A" size pack under Battery Amnesia. I would think that's a reasonable result?

 

[croissantking]

Finally died at 88 minutes with the "A" size pack under Battery Amnesia. I would think that's a reasonable result?

Yes, an hour and a half is what I get with mine and that's just normal use.

 

[jmacz]

I charged my "AA" size pack and then let Battery Amnesia drain it. It took 77 minutes to drain. That also looks like a good result.

BUT, as I'm charging it now, EMMpathy is showing a red 1480 for the measured total capacity... ?? Not sure why it's only getting 1480mAH. The pack is a 2100mAH. Could be the pack isn't as good as it's rated but previously, I had been seeing 1752mAH always. Mysterious.

 

[jmacz]

Ran Lind and of course it complains about errors since I've been using EMMpathy. I had it correct the errors. Lind seems to be writing the 1752mAH to the EMM. I then run EMMpathy and it again shows 1752mAH now. I don't know how those two values (factory default and measured total capacity) are used (if at all) but I'm guessing Lind is writing it. When I get a chance, I'll see if I can patch that to be a different value and then see what happens.

 

[jmacz]

I ran a few more complete discharge and recharge cycles. Honestly can't tell a difference between the "A" pack and the "AA" pack. Battery Amnesia is taking around 80 minutes to discharge either of them +/- 5-10 minutes (discharged individually, not with both batteries in the PB).

Obviously that's not a large enough sample set, I guess I'll get a better feel over time and more use, but at this point, both size batteries ("A" and "AA") fit although if you're going with a pre-built pack, AA is probably better since those pre-built packs are not optimized for space and thus you have more room with the AAs. If you're going A (which is what the original size was), you probably need to build your own pack using thin tabs and optimizing for space otherwise it won't fit. But as of now I cannot tell the difference between the two packs.

Also, EMMpathy every so often reports a measured total capacity less than 1752mAH.. I had a 1480, and a 1672. Not sure what actually reads/sets that (System or EMMpathy or the EMM). Lind corrects it back to 1752mAH. But I did not notice any change in behavior of the capacity based on this value.

 

[Iesca]

Seems like it would be really helpful if there were a modern software tool to replace EMMpathy and Lind that was a bit smarter about what it was doing, since those two weren't designed with re-packs in mind!

 

[3lectr1cPPC]

@jmacz
What temperature does your battery report when it hits the full charge mark while charging? Mine (the one that jumps to 100% at ~770mAH) does that jump at exactly 40 degrees C. I caught the moment it happened today.

 

[jmacz]

I think mine were both above 50C when it reaches full charge. With the 2A charger, it hit 60C .. but with the 1A charging, it was in the 50Cs.

 

[croissantking]

Ah bugger - the one I repaired today has died. I fully charged it, then ran the laptop off it until it had discharged and it’s now disappeared again.

So I’m back up to two batteries again. I bought a second-hand battery advertised as non-working but it had a good EMM board. It had uncorrectable errors so I changed the EEPROM with a new one while I had the board desoldered, then soldered it to my existing battery pack. It works great!

 

[jmacz]

Congrats!!!

 

[croissantking]

Performance is better than expected. I got 208 minutes out of BatteryAmnesia before it shut down. It’s curious how the graph flatlined at 50% discharge.

 

[jmacz]

Wow that’s a lot! I did end up seeing a few ~120 min drains on one of mine but never anything near 200min.

I have seen a similar graph before with the flat line around 50% with my batteries but it never had the sharp transition to the flat line. My graphs always had a curve that smoothed to a flat line for some period of time and then gradually curved into a downward slope again. Never those abrupt transitions to/from a flat line. Interesting.

 

[alexGS]

Performance is better than expected. I got 208 minutes out of BatteryAmnesia before it shut down. It’s curious how the graph flatlined at 50% discharge.

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?

I found my store-branded 2400mAh AA cells couldn’t handle the 1A charge rate (battery specs often quote a 500mAh charge rate). The measured capacity drops to only about 500mAh. Measurement is after a full discharge (to power off) and recharge cycle. Lind IBUS resets the battery and measured capacity is reset to 1752, but it will soon drop again. So I still need to buy some decent NiMH AA cells to try.

I liked the look of the 15V 1A plugpack. I presume that was wired to both VMain and VBatt in parallel. EDIT: no it isn’t, I found the post https://68kmla.org/bb/index.php?thr...r-re-cap-modern-replacement.38426/post-555377 - makes perfect sense that way, using two separate supplies to replicate the original safely. Top work again @jmacz

I’m doing a Mouser order this week and will finally order the EPROM replacement (thanks jmacz for that link too…)

 

[jmacz]

Cool, good luck with the EPROM change. I'm working on a Duo battery rebuild right now (it's all done, just curious what capacity I will get out of it and whether the ID chip still works in it or not). Need to also get back to looking at why my PB160 won't charge batteries fully whereas an external charger is able to charge it to full. Which reminds me, I need to go back and play with writing some software to help me debug some of this battery stuff.