milwaukee battery dead

[labello]

Hi guys I have this battery for impact wrench milwaukee I checked all of the battery cells and two of them was very low voltage, then I changed but it still gone no led about battery level status ... But i
I misured output pin and i have 19v, then I cleaned and I found this chip broken, can I found it on aliexpress just similar mark (R5F100BCA) or it must be the original one? Thank you so much for the answer

[petehall347]

Re: milwaukee battery dead

new one likely needs programming so ..............
any error codes on the charger ?
what voltage is it supposed to be at ?

[sam_sam_sam]

Re: milwaukee battery dead

You will be better off finding another battery pack that either has an issue with the battery fuel gauge not lighting all four of them 2 or 3 lighting up when the charger says that it is fully charged is more likely an issue with the battery cells are very unbalanced and the BMS protection board more than likely should be fine

If you have only one fuel gauge led lighting in this situation is if-e at best and is worse if the led is flashing because if is flashing it is a 50/50 chance that battery is severely down on charge or the BMS protection board has some type of issue that I have not figured out how to fix now if only one light is lighting on the fuel led then if you get lucky it will charge up and either be a unbalanced battery pack or if it charges up and lights all four fuel gauge lights it might be suffering diminishing running time but the BMS protection board should be alright

When you say very low on charge what voltages are we talking about more than 0.500 volts difference between battery cells if so then those battery cells that are that much lower more than likely are at there end of life syndrome there is no cure for this issue

If you charge up the battery cells to 4.20 let them sit for a month and recheck the voltage and if they are not still around 4.something volts them you have the issue that I discussed above about the end of life syndrome

One thing I would warn you about the replacement BMS protection boards that are being sold on EBay and AliExpress are not good quality and all the ones that I bought I had to get a refund so buyer be aware of this issue with replacement BMS protection boards for Milwaukee battery packs ( now if you are buying the repair kits for the Milwaukee battery packs that have the enclosure for the battery cells and the tabbing hardware and screws the quality is decent for the money but be prepared to get your money back for the BMS protection boards I mentioned above about the issue with them )

The ic chip that you are asking about is the charging/discharging monitoring system for the battery pack and as someone else mentioned earlier it probably needs to be programmed

One additional note when you run across a battery that is unbalanced I would suggest the following discharge the other cells down to lowest battery cell ( but not lower than 3.something volts for best results ) or ( unless the battery voltage is lower than 2.00 volts this will if-e at best ) and put it on the battery charger and see if when it is fully charged on the charger and you remove the battery from the charger does all four led lights on the fuel gauge if so then let the battery sit for a month and see if it still has four led lights on the fuel gauge if so you are ready to go for awhile if not then remove the battery cells that discharge by themselves and find some more that are not discharging by themselves and you should be ready to go again but just keep in mind that the running time is not going to be like a brand new battery would be

One thing I have not tried yet is to put the battery cells that are discharging themselves into a battery pack and see what kind-a preference would get from doing this is going to be a project experiment that I think about doing sometime soon

I am speaking from experience I have reconditioned Milwaukee battery packs before and have put brand new battery cells in them before as well

I hope this helps you

[labello]

Re: milwaukee battery dead

new one likely needs programming so ..............
any error codes on the charger ?
what voltage is it supposed to be at ?

No any errors..the leds are completely dead when I pushing the button, but I already test it in (diod mode) and they work . The voltage output could be 18v but I have 19v maybe beca5i replaced 2 cell battery dead...

[labello]

Re: milwaukee battery dead

You will be better off finding another battery pack that either has an issue with the battery fuel gauge not lighting all four of them 2 or 3 lighting up when the charger says that it is fully charged is more likely an issue with the battery cells are very unbalanced and the BMS protection board more than likely should be fine

If you have only one fuel gauge led lighting in this situation is if-e at best and is worse if the led is flashing because if is flashing it is a 50/50 chance that battery is severely down on charge or the BMS protection board has some type of issue that I have not figured out how to fix now if only one light is lighting on the fuel led then if you get lucky it will charge up and either be a unbalanced battery pack or if it charges up and lights all four fuel gauge lights it might be suffering diminishing running time but the BMS protection board should be alright

When you say very low on charge what voltages are we talking about more than 0.500 volts difference between battery cells if so then those battery cells that are that much lower more than likely are at there end of life syndrome there is no cure for this issue

If you charge up the battery cells to 4.20 let them sit for a month and recheck the voltage and if they are not still around 4.something volts them you have the issue that I discussed above about the end of life syndrome

One thing I would warn you about the replacement BMS protection boards that are being sold on EBay and AliExpress are not good quality and all the ones that I bought I had to get a refund so buyer be aware of this issue with replacement BMS protection boards for Milwaukee battery packs ( now if you are buying the repair kits for the Milwaukee battery packs that have the enclosure for the battery cells and the tabbing hardware and screws the quality is decent for the money but be prepared to get your money back for the BMS protection boards I mentioned above about the issue with them )

The ic chip that you are asking about is the charging/discharging monitoring system for the battery pack and as someone else mentioned earlier it probably needs to be programmed

One additional note when you run across a battery that is unbalanced I would suggest the following discharge the other cells down to lowest battery cell ( but not lower than 3.something volts for best results ) or ( unless the battery voltage is lower than 2.00 volts this will if-e at best ) and put it on the battery charger and see if when it is fully charged on the charger and you remove the battery from the charger does all four led lights on the fuel gauge if so then let the battery sit for a month and see if it still has four led lights on the fuel gauge if so you are ready to go for awhile if not then remove the battery cells that discharge by themselves and find some more that are not discharging by themselves and you should be ready to go again but just keep in mind that the running time is not going to be like a brand new battery would be

One thing I have not tried yet is to put the battery cells that are discharging themselves into a battery pack and see what kind-a preference would get from doing this is going to be a project experiment that I think about doing sometime soon

I am speaking from experience I have reconditioned Milwaukee battery packs before and have put brand new battery cells in them before as well

I hope this helps you

Hi thanks for your answer,
But what do you mean with (I hope this helps you) are dose projects or post? Thank you

[sam_sam_sam]

Re: milwaukee battery dead

Hi thanks for your answer,
But what do you mean with (I hope this helps you) are dose projects or post? Thank you

Both of them meaning that if you have an understanding of what the issues are with the BMS protection board and what can cause some of the issues then you have some of the tools to deal with them