6 hours ago, Sagy89 said:

Hi guys, So the whole story.. I was swapping out battery packs in one of my pylontech batteries today as it had a dead cell and though while I've got it isolated from the bank, I thought I'd update the firmware to get all the cell data available in the Victron inverter. I was completely unobservant and for some reason, fixated on just selecting the zip so as not to worry about selecting the right chip firmware, I completely forgot the fact that I do not have us2000c batteries at all 🤦‍♂️ I have us2000b batteries, So I have bricked a BMS by stupidly flashing the incorrect firmware.
I have tried the update tool several times to recover the BMS but following the instructions included in the file, it just sits at "Get into bootloader mode" for as long as I leave it. Is there any specifics as to when or how long the red button needs to be pressed on the battery to get it into bootloader mode? Or is my BMS just simply dead now?

Hi @Sagy89

These are the instructions given by Pylontech support for cases like this. For a couple of ppl they worked okay.

1. Connect the debug cable to this software and the battery (attention: at this time please do not switch the battery on)

2. Cpen the software, check Immediate Update checkbox

3. Click Connect.

4. Click Browse to select the correct firmware.

5. Then click Program and switch on the battery by hard switch and the red soft start button immediately.

Pylontech Upgrade Tool.zip us2000b _v2.9_Crc.bin

Just one note to add:

1) Once you click "connect" the software will reply with "connected", but actually it means that the COM port was opened, nothing more. It DOES NOT mean that the connection to the battery itself was successful.

2) Once you click "program" you have approximately 2 seconds to turn on the battery. If you are not quick enough, procedure will fail and you have to repeait.

Thank you @Youda I'll have another go tomorrow morning. For now I have stripped the cells out and fitted them into a us2000c chassis that has a working BMS but failed cells. Hopefully I can get this one operational again too.
If all else fails, do you know if anyone has had any success dumping and writing the flash chip? I just noticed that it has a winbond chip in there there, I have all the tools to read and write these IF this is where the firmware is actually located. I have 4 identical us2000b batteries, I was thinking I could read one of my working ones and write it to the bricked one. The serial number won't match what it should be any more but at least it might work.

On 2025/07/26 at 4:22 PM, Sagy89 said:

dumping and writing the flash chip?

Understood. Personally I never heard of anyone doing this on Pylontech BMS, not even a repair center.

Like with many devices, bootloader is a separate code that does not get rewritten with the standard FW upgrade. Therefore, you should still be able to unbrick your BMS.

Hi,

I have a bricked Pylontech Battery US2000 (US2000NB02V00201 )

I assume this is the US2000B Plus Version and using the us2000b v2.9Crc FW to try and restore the battery.

But I can't get it do the FW Upgrade as the update tools show this error

26-03-22 12:53:49->Connecting...

26-03-22 12:53:50->Connected.

26-03-22 12:54:02->Fail to update

26-03-22 12:54:02->Fail to get into bootloader mode

Am I using the correct fw?

Or why can't I get into the Bootloader?

Or is the BMS faulty?