Not a genius, just stubborn :) I looked for a long time, and it drove me crazy how there are a ton of replacement boards and a ton of fix-it articles for the other types, but not these Lithium+ HPs! Glad it was helpful.
@@colindgrant Well genius or not you are the only one I have found online that has figured out the P19# series mystery boards so for that you deserve all the credit for figuring it out. I will try your suggestion of balance charging to 4.15 per cell and running it in a couple different tools to see if the board snaps out of it. Again thank you for your help.
Very good, I enjoyed dismantling engines from neighbors old mowers that quit running, 50+ yrs ago which led to a life long career-after the engines I did some electrical-then collision and paint in my own shop 23yrs - you just never know what you will find if you are curious and take something apart - maybe a Lifetime 🤷♂️
@@DanielC-e9t No kidding! My career and hobbies couldn’t have been predicted by the classes I took. They’re due to the stuff I took apart spawning a desire for new skills. 👍
The reason the 6 ah battery uses enlarged spacing between the cells is because the Murata VT6 cells will be able to deliver more amperage but will generate more heat and reach a higher temperature. I believe it was a design parameter to distance the cells from one another. Curious what the discharge was from soldering the zero volt terminal? Looks like the solder might have touched the B+ strip on the contact tower. Great video, thank you!
@@gregs3580 ahhhh that makes sense! In the 5s2p configuration the VT6 can do the job since cells are paralleled (halving the current load per cell) but they require more space for ventilation. However in a 5s1p configuration they probably can’t deliver enough sustained current, regardless of cooling. Hence the reason for the 21700 cells instead. Sound plausible? As far as the short, yeah I touched the zero volt terminal to B+ like you said. I suspect the short was cut…short…by the solder instantly melting. So probably not much energy used but I too am curious how much!
@@colindgrant Generally Ryobi uses Samsung on their older models which are consistent and notable high quality. Newer ones including the P191 etc have used EVE and other more obscure cells.Found some which used "Great Power? . When I was trouble shooting a P193 I was literally shocked to see the Sony cells. They are almost land mark quality as far as low internal resistance and sustained durations of high levels of current output. But there are 18650 cells which can deliver high current to in a 5s1p config, but clearly a 21700 has an advantage.
I have a P191 and I used your method to "reset" the circuit board, however I am having a problem. I rebuilt the battery with Samsung 25R 18650's. I ensured they were balanced before rebuilding the pack. after your reset procedure I am now getting 18.6 volts at the post and when I press the fuel gage it shows 2 green bars. The problem I am having is it will not charge. When I pop it in the charger it flashes red for 10 seconds then shows green (Like it is fully charged). I know it is not fully charged because I balanced all the cells to only 3.7 volts. Any ideas as to why it will not charge? could the board be fried? Or could one of the two mosfets be bad?
Sorry to hear that. You are probably right - either the board is friend or the charging MOSFET(s) are bad. I had a fried board, but in my case it was obvious because the fuel gauge didn't work, instead the LEDs flashed left to right and back. You've probably already thought of these, but just to list them, some things to try are: - use the battery in various tools, older and newer ones - plug the battery into various chargers - directly balance charge your cells to 4.15 volts per cell, this is close to what chargers consider 'full'. Then repeat trying in various tools, and assuming it can power tools, run the battery down to a level where the pack needs a charge, and try chargers again. - most drastic is to desolder your board from the cells so that it can go completely 'off', then resolder. I can't say for sure, but I think I saw this work for me once, and I suspect it had something to do with the order in which the board saw cells. Wish I could say conclusively... I have suspected the MOSFETs and desoldered many times, only to test them on the bench and find that they are ok. I haven't seen failed MOSFETs in a Ryobi pack yet. Good luck, and report back if you discover a solution!
THANK YOU!! I have been searching forever for the reset on the P191 and no one has put out this information You sir are a genius.
Not a genius, just stubborn :) I looked for a long time, and it drove me crazy how there are a ton of replacement boards and a ton of fix-it articles for the other types, but not these Lithium+ HPs! Glad it was helpful.
@@colindgrant Well genius or not you are the only one I have found online that has figured out the P19# series mystery boards so for that you deserve all the credit for figuring it out. I will try your suggestion of balance charging to 4.15 per cell and running it in a couple different tools to see if the board snaps out of it. Again thank you for your help.
Great video. Wish I had seen this before.
That’s beyond my ability to tinker with, but it was interesting and I’m glad you’re working on repairing batteries that would otherwise get tossed.
Great to hear. It was beyond my ability less than 5 years ago, but University of UA-cam helped :)
Very good, I enjoyed dismantling engines from neighbors old mowers that quit running, 50+ yrs ago which led to a life long career-after the engines I did some electrical-then collision and paint in my own shop 23yrs - you just never know what you will find if you are curious and take something apart - maybe a Lifetime 🤷♂️
@@DanielC-e9t No kidding! My career and hobbies couldn’t have been predicted by the classes I took. They’re due to the stuff I took apart spawning a desire for new skills. 👍
The reason the 6 ah battery uses enlarged spacing between the cells is because the Murata VT6 cells will be able to deliver more amperage but will generate more heat and reach a higher temperature. I believe it was a design parameter to distance the cells from one another.
Curious what the discharge was from soldering the zero volt terminal? Looks like the solder might have touched the B+ strip on the contact tower.
Great video, thank you!
@@gregs3580 ahhhh that makes sense! In the 5s2p configuration the VT6 can do the job since cells are paralleled (halving the current load per cell) but they require more space for ventilation. However in a 5s1p configuration they probably can’t deliver enough sustained current, regardless of cooling. Hence the reason for the 21700 cells instead. Sound plausible?
As far as the short, yeah I touched the zero volt terminal to B+ like you said. I suspect the short was cut…short…by the solder instantly melting. So probably not much energy used but I too am curious how much!
@@colindgrant Generally Ryobi uses Samsung on their older models which are consistent and notable high quality. Newer ones including the P191 etc have used EVE and other more obscure cells.Found some which used "Great Power? . When I was trouble shooting a P193 I was literally shocked to see the Sony cells. They are almost land mark quality as far as low internal resistance and sustained durations of high levels of current output.
But there are 18650 cells which can deliver high current to in a 5s1p config, but clearly a 21700 has an advantage.
I have a P191 and I used your method to "reset" the circuit board, however I am having a problem. I rebuilt the battery with Samsung 25R 18650's. I ensured they were balanced before rebuilding the pack. after your reset procedure I am now getting 18.6 volts at the post and when I press the fuel gage it shows 2 green bars. The problem I am having is it will not charge. When I pop it in the charger it flashes red for 10 seconds then shows green (Like it is fully charged). I know it is not fully charged because I balanced all the cells to only 3.7 volts.
Any ideas as to why it will not charge? could the board be fried? Or could one of the two mosfets be bad?
Sorry to hear that. You are probably right - either the board is friend or the charging MOSFET(s) are bad. I had a fried board, but in my case it was obvious because the fuel gauge didn't work, instead the LEDs flashed left to right and back.
You've probably already thought of these, but just to list them, some things to try are:
- use the battery in various tools, older and newer ones
- plug the battery into various chargers
- directly balance charge your cells to 4.15 volts per cell, this is close to what chargers consider 'full'. Then repeat trying in various tools, and assuming it can power tools, run the battery down to a level where the pack needs a charge, and try chargers again.
- most drastic is to desolder your board from the cells so that it can go completely 'off', then resolder. I can't say for sure, but I think I saw this work for me once, and I suspect it had something to do with the order in which the board saw cells. Wish I could say conclusively...
I have suspected the MOSFETs and desoldered many times, only to test them on the bench and find that they are ok. I haven't seen failed MOSFETs in a Ryobi pack yet.
Good luck, and report back if you discover a solution!