Xiaomi M365PRO, Repair Manual

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Troubleshooting
Troubleshooting
Trouble ​ :
The battery does not work, the LED on the BMS board does not blink
Solution ​ :
1. Connect the charger: normally this starts the correctly connected BMS.
2. Check the connection is correct, in case of an error - reconnect correctly.
3. Make sure that all the parallels of the battery pack are OK: their voltage should be in the range of about
2.5 to 4.2 volts.
Trouble ​ :
BMS starts up, but after about 30 seconds it shuts down itself.
Solution ​ :
Check if the voltage drops at least one parallel lower than the “BMS shutdown undervoltage”
parameter(it’s default value is 2.6V). If yes, then after starting BMS, leave the charger connected so that the
problematic parallel is charged.
Trouble ​ :
BMS flashes LED, but the scooter does not turn on.
Solution ​ :
1. Check battery output voltage. If it is in the range of about 30 to 42 volts, it means that the BMS board
and the battery pack are OK, and the problem should be looked for in the scooter controller.
2. If the voltage at the output of the scooter is below 30 volts, pay attention at the blinking LED, it signals
errors that disable the discharge of the battery:
a) a short flash once per second means at least one of the parallels of the battery is discharged
below the level of the “Cell undervoltage” parameter. It is important to understand why this
happened. If the battery is completely discharged, and all the cells are evenly discharged to a
low level - this is the normal mode of operation, there is nothing to worry about, you just need to
connect the charger and charge the battery. But if only one parallel dropped down - this is a
cause to look for broken contacts or a faulty cell.
b) continuous light - means the protection against overcurrent or short circuit protection has
activated. In this case, you just have to wait 10-20 seconds.
c) a long flash once a second - it means that the protection against temperature rise has
activated. In this case, wait until the temperature drops.
d) a short flash every half a second - this is normal mode, there are no errors disabling the
discharge of the battery. If the LED blinks like this, but there is no voltage at the BMS output, it
means the board malfunction, please contact the technical support.
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