I built an electric bike battery with the DIY BMS. I have used it for 2 weeks and it has been great, but now it has become unreliable. It started with I couldn’t get the battery to power up, now I have on a test bench, and it does power up, but it shuts down when I turn off the bike motor button.
I am not a professional, if there is a better way to turn on and off the DC-DCs and controller, please let me know. I just can’t understand why it has worked great and now is just not working.
The Arduino Nano represents the BMS controller, and I am using one of its relays to control the low voltage cutoff. The motor relay is a 12v car relay that can handle 30A.
The motor can take 30 amps max, the battery is a 17s li-ion with 18650s 7 in series. I am running it from 51v to 68v.