PCB188002, 8 red flashes & 16 red flashes

[turenabo]

I successfully downloaded your firmware to the board, but 8 red flashes when I pluged charger, 16 red flashes when I push the vaccum cleaner button. Need your help, many thanks.

I just balanced all cells, then downloaded firmware, I don't know why it over current. Is it hardware problem?

[tinfever]

Does the 16 red flash error occur even without any load connected to the battery? If so, it does sound like a hardware problem.

I'm not sure what exactly would cause that to happen without any load attached to the battery pack. The brown out error code 16 only happens when the ISL94208 literally browns out due to lack of power, but the cells would have to be really really bad to not even supply that IC with no other load.

If the code 16 issue only occurs with a load attached then it is a different story. That probably just means the cells are a bit too weak to handle the motor inrush current. I have a theory that could be worked around by adding an extra capacitor on the board. I think there was some discussion about that on the EEVBlog forum thread liked in the readme.

[turenabo]

Many thanks, it's indeed hardware problem, now it workes. I exchanged cell pack with another same battery pack. You are right, the cells are too bad with above 22mΩ internal resisitance, I guess it's almost end of life, cells in another pack is around 16mΩ.