Successfully recelled a battery, is it safe tu use?

[huohuo]

Hello, recently recelled a T61 9 cell battery with 3,6v cells, from what I understand, the total voltage of the battery equals 32,4v which is in no way the acceptable value of 11 volts. Should I attempt to lower the voltage, or is it safe to use?
PS. I wanted to say that I fully understand that this forum might be not the best place to post about my battery issues since it's dedicated to Thinkpads, not voltages.

[BillP]

No, that is not safe to use. It appears you connected all 9 cells in series which is wrong. The connection should be three parallel sets of three series cells to get nominally 10.8 volts.

[axur-delmeria]

Hello, recently recelled a T61 9 cell battery with 3,6v cells, from what I understand, the total voltage of the battery equals 32,4v which is in no way the acceptable value of 11 volts. Should I attempt to lower the voltage, or is it safe to use?

1. Did you actually measure the voltage of the battery pack after connecting the cells together?

2. Did you duplicate how the cells were connected? If not, then throw that pack away-- you obviously didn't do enough research before beginning that project.

[huohuo]

Hello, recently recelled a T61 9 cell battery with 3,6v cells, from what I understand, the total voltage of the battery equals 32,4v which is in no way the acceptable value of 11 volts. Should I attempt to lower the voltage, or is it safe to use?

1. Did you actually measure the voltage of the battery pack after connecting the cells together?

2. Did you duplicate how the cells were connected? If not, then throw that pack away-- you obviously didn't do enough research before beginning that project.

I am yet to measure the voltage.
I haven't touched original nickel plates, just swapped the cells, so all cells have the original configuration.

[kfzhu1229]

Hello, recently recelled a T61 9 cell battery with 3,6v cells, from what I understand, the total voltage of the battery equals 32,4v which is in no way the acceptable value of 11 volts. Should I attempt to lower the voltage, or is it safe to use?
PS. I wanted to say that I fully understand that this forum might be not the best place to post about my battery issues since it's dedicated to Thinkpads, not voltages.

The best way to have our assurance is for you to go and take photos, take detailed photos also in all the possible angles you can imagine. (upload it to imgur or some kind of 3rd party website like that)
I rebuild laptop batteries myself with some good experience by now and I tend to pixel peep at my work after to identify whether there are any issues I should be fixing

[axur-delmeria]

Wait a sec.

So you just removed the bad cells, and put in the new ones, nothing more?

Original battery packs have a protection circuit that can detect if the battery voltage has dropped to zero (or the cells disconnected). Once that happens, the BMS (battery management system) will render the pack "dead" (refuse to charge it). That's why proper recelling involves connecting a different power source to the battery tabs before removing the old cells. Note that I've never recelled a battery pack, but have read other posts and did some research because I've been planning to try my hand at it.

[huohuo]

Wait a sec.

So you just removed the bad cells, and put in the new ones, nothing more?

Original battery packs have a protection circuit that can detect if the battery voltage has dropped to zero (or the cells disconnected). Once that happens, the BMS (battery management system) will render the pack "dead" (refuse to charge it). That's why proper recelling involves connecting a different power source to the battery tabs before removing the old cells. Note that I've never recelled a battery pack, but have read other posts and did some research because I've been planning to try my hand at it.

This is what I did, I remember reading that cutting the power to bms will render it dead but I was silently hoping that this will not happen in my case. But I'm pretty sure bms died (charge stays at 3%). Is there something that I can actually do, or it's just best to throw it out?

[kfzhu1229]

This is what I did, I remember reading that cutting the power to bms will render it dead but I was silently hoping that this will not happen in my case. But I'm pretty sure bms died (charge stays at 3%). Is there something that I can actually do, or it's just best to throw it out?

It's actually pretty simple. If your battery LED is rapidly flashing orange and the power manager said the battery experienced permanent failure, then it's fully declared dead, there is no fixing that short of reprogramming the BMS, which is something even I am still short of knowledge of doing.
The whole point of me doing all of it without ever disconnecting power to the BMS is to avoid precisely that, not that I love doing it in that method as it is way more prone to short circuiting with one false move. And in cases with known evil BMS like T430/T530, the old and new cells must also roughly match in voltage when I do the bridging to swap them hot.

[huohuo]

This is what I did, I remember reading that cutting the power to bms will render it dead but I was silently hoping that this will not happen in my case. But I'm pretty sure bms died (charge stays at 3%). Is there something that I can actually do, or it's just best to throw it out?

It's actually pretty simple. If your battery LED is rapidly flashing orange and the power manager said the battery experienced permanent failure, then it's fully declared dead, there is no fixing that short of reprogramming the BMS, which is something even I am still short of knowledge of doing.
The whole point of me doing all of it without ever disconnecting power to the BMS is to avoid precisely that, not that I love doing it in that method as it is way more prone to short circuiting with one false move. And in cases with known evil BMS like T430/T530, the old and new cells must also roughly match in voltage when I do the bridging to swap them hot.

Geez, and here I thought I could cheap out on batteries, it blinks rapidly, so it's a lost cause. Thanks a lot for the help though.

PS. I have seen some people bringing bms back to life by bridging two positives, do you know anything about this method?

[kfzhu1229]

Geez, and here I thought I could cheap out on batteries, it blinks rapidly, so it's a lost cause. Thanks a lot for the help though.

PS. I have seen some people bringing bms back to life by bridging two positives, do you know anything about this method?

If you tried that already and didn't work, it won't work ever again unfortunately. I have not seen that method work on any T6x/X6x batteries, and I know that method works on some T4x batteries but not others, and certainly not the T42 battery I rebuilt.
Imo the point about these rebuilds is if done properly, not as much about saving much money on batteries, but rather either do it for batteries that can't be found, have compatibility issues with aftermarket batteries, or that you absolutely needed the performance in either battery life and/or power draw that only an original battery with replaced quality branded cells can provide.
In my case they do end up cheaper than aftermarket replacements, but only when I buy the replacements shipped to Canada, if I were to buy these straight from China then aftermarket is dirt cheap - starting at the equivalent of <10 euros for 6 cell and <15 euros for 9 cell. My LG cells cost about the equivalent of 16 euros for 6 cell, but of course they're far and wide better than unbranded 6 cells, and might even be on par with unbranded 9 cells.
Also, from my experience, if a rebuild job is very sketchily done, it can in fact be unsafe, and it's far worse for a battery to go thermal runaway on you when you already sealed the case shut vs when you are still building and testing things (you can remove the offending short quickly). This is why I take loads of photos for every battery I rebuild, and zoom in and pixel peep to inspect if all joints and insulations are up to comparable standard to out of factory, and I suggest you do the same, so that you can confidently fit the battery inside your laptop and forget about the fact that you rebuilt the battery pack.

[huohuo]

Geez, and here I thought I could cheap out on batteries, it blinks rapidly, so it's a lost cause. Thanks a lot for the help though.

PS. I have seen some people bringing bms back to life by bridging two positives, do you know anything about this method?

If you tried that already and didn't work, it won't work ever again unfortunately. I have not seen that method work on any T6x/X6x batteries, and I know that method works on some T4x batteries but not others, and certainly not the T42 battery I rebuilt.
Imo the point about these rebuilds is if done properly, not as much about saving much money on batteries, but rather either do it for batteries that can't be found, have compatibility issues with aftermarket batteries, or that you absolutely needed the performance in either battery life and/or power draw that only an original battery with replaced quality branded cells can provide.
In my case they do end up cheaper than aftermarket replacements, but only when I buy the replacements shipped to Canada, if I were to buy these straight from China then aftermarket is dirt cheap - starting at the equivalent of <10 euros for 6 cell and <15 euros for 9 cell. My LG cells cost about the equivalent of 16 euros for 6 cell, but of course they're far and wide better than unbranded 6 cells, and might even be on par with unbranded 9 cells.
Also, from my experience, if a rebuild job is very sketchily done, it can in fact be unsafe, and it's far worse for a battery to go thermal runaway on you when you already sealed the case shut vs when you are still building and testing things (you can remove the offending short quickly). This is why I take loads of photos for every battery I rebuild, and zoom in and pixel peep to inspect if all joints and insulations are up to comparable standard to out of factory, and I suggest you do the same, so that you can confidently fit the battery inside your laptop and forget about the fact that you rebuilt the battery pack.

I haven't tried bridging two positives together, and after reading your post I don't have intentions for doing so.
My original plan with the whole recelling thing was to swap the cells in my dead batt for the ones with more capacity, on the paper recelling would cost 5 USD less than buying an used OEM one. But at this moment it costs more than an used OEM, since I had to buy another dead pack because nickel plates broke off the original PCB.
I'm probably going to disassemble my contraption, because I can't really do anything with the bms, and I don't want to potentially break the new cells.

[kfzhu1229]

I haven't tried bridging two positives together, and after reading your post I don't have intentions for doing so.

It is something that has no harm in trying and I thought that would be the first thing you would've tried. But yeah I am not hopeful of this BMS ever working again. If it is any comforting, the T6x/t400/t500 batteries kinda suck. I've gone through so many T6x batteries from the thinkpads I've taken in, all 6 cell, with two of them in the 14.1 widescreen flavour, only one of the latter survived after reviving all the cells with CID reset before I even attempted plugging the battery in. I bought the other widescreen battery with the intention of it being good enough to flash the middleton BIOS on my T61, it did that, but died 18 months after at which point I opened it up the cells were bathed in battery juice. I don't know why they age so poorly when their charging current and voltage thresholds weren't aggressive, yet I still had better luck with Dell D620/D630 and HP Compaq batteries

My original plan with the whole recelling thing was to swap the cells in my dead batt for the ones with more capacity, on the paper recelling would cost 5 USD less than buying an used OEM one. But at this moment it costs more than an used OEM, since I had to buy another dead pack because nickel plates broke off the original PCB.
I'm probably going to disassemble my contraption, because I can't really do anything with the bms, and I don't want to potentially break the new cells.

That's pretty standard affair I get into when I first attempting rebuilding batteries, I haven't sorted out where I should be buying things. Turns out reusing existing nickel strips is actually more difficult than you think to get it just right and I end up finding a source to buy a batch of 0.1mm thinner nickel strips so they solder (and also spot weld) way easier for the times I needed to modify the battery pack wiring after I had the seller spot weld it.
I know this may seem very discouraging, but I find the truth of getting into this job is that it takes a lot of trial and error, lots of failures and sketchy attempts before anything comes to fruition. Just hope that for your said failure attempts, you don't end up with a nasty thermal runaway you couldn't ressolve in time and have it burn things down...