Wow, you saved me a lot of time! My issues were the transformer with two coils shorted together and a burned diode next to it. Also I damaged a super tiny smd resistor next to SMT32 while peeling off the silicon, I don't know what's the value of that resistor so I blindly put 2KOhm, it gives 2.4V for the MC and still working, according to datasheet it needs at least 2V. I replaced transformer with DA2320-ALC, it works now! Thx!
I’ve got a 7.5 that’s acting up. It will show fully charged on the charger, then indicate it’s only 2/5. I’m going to try cleaning and re-seating the connector as you’ve done with this 5 Ah and see how it goes. Great content as usual!!!
Also hold down the button for 5-10 secs until it flashes. It seems to be a type of reset on Gen3 boards, but I guess I never really call it that since I am not 100% it resets truly. It seems to flash and show differently afterwards on some packs. Thanks for your kind comment!
Awesome video, thanks for sharing I've learned a ton from it. A majority of the bad 5AH batteries i come across have this problem , and the others have a bad temp sensors.
I got two 5AH batteries that had no power which was the same problem, the transformer. I got curious about the transformer and tried to do some research which lead me to a forum post on EEVblog which may be the post mentioned in your video. I went with the P0926NL because the ohm reading was closer to the old transformer vs the DA2320, also had to make a custom pcb to adapt it. So far it's been working!
@@Bi0 I do have the files for it. Just a heads up when I say adapter, I meant just a board so the pins are in the correct order. You will still need to solder wires from the BMS board to the adapter.
Awesome. Just to mention if anyone desires to share a file like this with the community you can use the Facebook group On The Bench if you would like. If you have other outlets or your own group please let us know so we can support that as well! Thanks for any sharing it helps a lot!
Apologies if I missed it, but what is the purpose of the DC-DC converter? Wouldn't a LDO regulator do the job? The LEDs are the only thing drawing power in the milliamps, and they're only on for a few seconds.
Yes, it seems overkill to me for sure. Not that I am an EE so I could absolutely be missing something. I have mentioned the Converter a little in some other older EGO video, but I have not talked much about it since I have many questions also. I think going from almost 60V down to 5V or 3.3V typically a converter is used for efficiency, but I don't really know why it's so complicated. It has 2 lower level outputs and 3 separate busses it seems. The BMS has 2 microcontrollers, also a calendar chip for pack maintenance (the pack will self discharge to around 30% after one month of storage). This is the BMS board I asked you awhile back if you had ever looked into.
@ThriftyToolShed i might have to look at those board images you linked. I guess a dual output voltage transformer can save components as you only need 1 switching mosfet. I would have thought capacitive buck converter down to 12V (was 12V one of the transformer outputs?), then LDO down to 3.3v for the lower voltage bus would be better. At these power levels you can easily find ICs for synchronous buck with the mosfets built in - just have to BYO capacitor. Anyway, sounds like an interesting circuit.
@@toolscientist It would be awesome if you could share more about this board. I have worked on these starting back around 6 years ago with the very first EGO pack repair. Since these packs and tools are beginning to take the place of many small engines I don't want to lose the ability to fix things ourselves when these fail and they do fail. Your take or video on these type of BMS would be awesome!
It doesn't. it just helps with pads and traces. I need to send you a board. I would send a complete pack, but I still only have 1 complete Gen3 pack. The older packs are similar but don't have the white wire. I don't think it matters except on 10Ah packs? Now the white wire is exactly what one of our conversations was on a while back. it may have something to do with the SMD 60A fuse modules on the 10Ah and larger packs. I plan to talk a bit more on that subject in the future as well. The same type SMD protection that you found on the newer Makita packs! Interesting.... We need to find a way to get you a 10 ah pack... They are expensive!
I had two 7.5 ah batteries start acting up and flashing red back in November. "Coincidentally" they had also just passed out of the warranty period. When I took them apart I couldn't see anything wrong, voltages were all the same and within spec. No swelling or visible damage. Oddly enough when I plugged the BMS back it it read as fine. Haven't had an issue with it since. Now I haven't reversed the logic chips or anything, but I am highly suspicious they may have a timer in those gen 3 boards set to kill the battery just after the warranty period and that disconnecting the BMS resets that timer. Like I said its been about 6 months and no further issues from the disassembled/reassembled batteries.
Excellent job getting the pack back working! I have seen several packs work after doing that, but it was absolutely because of light corrosion or poor connection at the tiny connectors. I have not had enough Gen3 packs to say anything definitively most of the ones I am referring to were Gen1 or Gen2. At times it takes plastic safe contact cleaner or a gentle scrubbing of the tiny connectors to get it working again.
Good demo for me because of owning equipment that uses the 56vdc battery pack. Question comes to mind if possible to repair windings? I know it's done with radio IF transformers . Thanks for your time!
I truly wonder the same thing. I honestly had issues simply removing all the silicone and solder from the pins on this tiny thing. I really wish I could rewind it, but it's so tiny even under the microscope I wonder how hard it would be. I do see bobbins for sale similar to these that you can wind your own so surely someone has done it. Excellent question. Maybe someone will share in the comments if they have done that before. Thanks for your kind comment!
Wow, you saved me a lot of time! My issues were the transformer with two coils shorted together and a burned diode next to it.
Also I damaged a super tiny smd resistor next to SMT32 while peeling off the silicon, I don't know what's the value of that resistor so I blindly put 2KOhm, it gives 2.4V for the MC and still working, according to datasheet it needs at least 2V.
I replaced transformer with DA2320-ALC, it works now! Thx!
Awesome job! Thanks for sharing!
I’ve got a 7.5 that’s acting up. It will show fully charged on the charger, then indicate it’s only 2/5. I’m going to try cleaning and re-seating the connector as you’ve done with this 5 Ah and see how it goes. Great content as usual!!!
Also hold down the button for 5-10 secs until it flashes. It seems to be a type of reset on Gen3 boards, but I guess I never really call it that since I am not 100% it resets truly. It seems to flash and show differently afterwards on some packs. Thanks for your kind comment!
Awesome video, thanks for sharing I've learned a ton from it. A majority of the bad 5AH batteries i come across have this problem , and the others have a bad temp sensors.
Awesome! Thanks for sharing and thanks for your kind comment!
I got two 5AH batteries that had no power which was the same problem, the transformer. I got curious about the transformer and tried to do some research which lead me to a forum post on EEVblog which may be the post mentioned in your video. I went with the P0926NL because the ohm reading was closer to the old transformer vs the DA2320, also had to make a custom pcb to adapt it. So far it's been working!
Awesome job! Thanks for sharing this!
Do you happen to have the PCB file for the adapter you made by chance?
@@Bi0 I do have the files for it. Just a heads up when I say adapter, I meant just a board so the pins are in the correct order. You will still need to solder wires from the BMS board to the adapter.
Awesome. Just to mention if anyone desires to share a file like this with the community you can use the Facebook group On The Bench if you would like. If you have other outlets or your own group please let us know so we can support that as well! Thanks for any sharing it helps a lot!
Well done everybody. Great repair.
Thanks for your kind comment!
Excellent video! Thank you!
Good job. Very satisfying!
Thanks for your kind comment!
Great job 👍 enjoyed it
So glad! Thanks so much for your kind comment!
Apologies if I missed it, but what is the purpose of the DC-DC converter? Wouldn't a LDO regulator do the job? The LEDs are the only thing drawing power in the milliamps, and they're only on for a few seconds.
Yes, it seems overkill to me for sure. Not that I am an EE so I could absolutely be missing something. I have mentioned the Converter a little in some other older EGO video, but I have not talked much about it since I have many questions also. I think going from almost 60V down to 5V or 3.3V typically a converter is used for efficiency, but I don't really know why it's so complicated. It has 2 lower level outputs and 3 separate busses it seems. The BMS has 2 microcontrollers, also a calendar chip for pack maintenance (the pack will self discharge to around 30% after one month of storage). This is the BMS board I asked you awhile back if you had ever looked into.
@ThriftyToolShed i might have to look at those board images you linked. I guess a dual output voltage transformer can save components as you only need 1 switching mosfet. I would have thought capacitive buck converter down to 12V (was 12V one of the transformer outputs?), then LDO down to 3.3v for the lower voltage bus would be better. At these power levels you can easily find ICs for synchronous buck with the mosfets built in - just have to BYO capacitor. Anyway, sounds like an interesting circuit.
@@toolscientist
It would be awesome if you could share more about this board. I have worked on these starting back around 6 years ago with the very first EGO pack repair. Since these packs and tools are beginning to take the place of many small engines I don't want to lose the ability to fix things ourselves when these fail and they do fail. Your take or video on these type of BMS would be awesome!
I just rewatched. 10.25V and 8.25V buses. That doesn't make a lot of sense. Does the board teardown have a parts list, too?
It doesn't. it just helps with pads and traces. I need to send you a board. I would send a complete pack, but I still only have 1 complete Gen3 pack. The older packs are similar but don't have the white wire. I don't think it matters except on 10Ah packs? Now the white wire is exactly what one of our conversations was on a while back. it may have something to do with the SMD 60A fuse modules on the 10Ah and larger packs. I plan to talk a bit more on that subject in the future as well. The same type SMD protection that you found on the newer Makita packs! Interesting....
We need to find a way to get you a 10 ah pack...
They are expensive!
I had two 7.5 ah batteries start acting up and flashing red back in November. "Coincidentally" they had also just passed out of the warranty period. When I took them apart I couldn't see anything wrong, voltages were all the same and within spec. No swelling or visible damage. Oddly enough when I plugged the BMS back it it read as fine. Haven't had an issue with it since.
Now I haven't reversed the logic chips or anything, but I am highly suspicious they may have a timer in those gen 3 boards set to kill the battery just after the warranty period and that disconnecting the BMS resets that timer. Like I said its been about 6 months and no further issues from the disassembled/reassembled batteries.
Excellent job getting the pack back working! I have seen several packs work after doing that, but it was absolutely because of light corrosion or poor connection at the tiny connectors. I have not had enough Gen3 packs to say anything definitively most of the ones I am referring to were Gen1 or Gen2. At times it takes plastic safe contact cleaner or a gentle scrubbing of the tiny connectors to get it working again.
Good demo for me because of owning equipment that uses the 56vdc battery pack. Question comes to mind if possible to repair windings? I know it's done with radio IF transformers . Thanks for your time!
I truly wonder the same thing. I honestly had issues simply removing all the silicone and solder from the pins on this tiny thing. I really wish I could rewind it, but it's so tiny even under the microscope I wonder how hard it would be. I do see bobbins for sale similar to these that you can wind your own so surely someone has done it. Excellent question. Maybe someone will share in the comments if they have done that before. Thanks for your kind comment!