Leafmotor

Lead acid,LiFePo4,LiMn2O4,any kind of battery has use life.Generally 1 year warranty for battery.

Battery is a special good that is different from brushless controller,hub motor.Why?Controller and motor,if you don’t use for 1 year.Still no problem.But battery,you should charge it each two weeks,even if you don’t use.

For lithium battery,there are many cells make up of one battery.
Below we talk about LiMn2O4 battery first.
Now 4.2V 4Ah LiMn2O4 cell is familiar with us.
7 series for 24V,10 series for 36V,13 series for 48V
1.1 set of 24V 16Ah LiMn2O4 needs 28 pcs cells;
2.1 set of 36V 12Ah LiMn2O4 needs 30 pcs cells;
3.1 set of 36V 16Ah LiMn2O4 needs 40 pcs cells;
4.1 set of 48V 12Ah LiMn2O4 needs 39 pcs cells.

Too many cells for one battery,only one cell is sick.The whole of battery will be broken.
You will find that,full chargerd your battery,but it only drive your bicycle several meters,the motor will stop.
Because BMS found one sick cell,in order to protect other cells.BMS turns off power.

Now you need to replace sick cell,pls test as below,you will find it.
It’s a 36V li-ion battery.
Remove the battery end cover containing the charger socket. You will find a printed circuit board (PCB).
It is a battery management system (BMS) which equalizes the charge in each of the cells.
The wire B1 is the one attached to the battery anode. Connecting his professional quality voltmeter to the battery anode and to the other nine wires in succession.

There is one 10-Pin connector on this PCB. (B10 B9 B8 B7 B6 B5 B4 B3 B2 B1)

Measure the voltage between
the green wire and other nine wires as below:

B1 green wire to: Specification
B2 yellow wire(the second wire) 3.6V ~ 4.15V
B3 yellow wire(the third wire) 7.2V ~ 8.30V
B4 yellow wire(the fourth wire) 10.8V ~ 12.45V
B5 yellow wire(the fifth wire) 14.4V ~ 16.60V
B6 yellow wire(the sixth wire) 18.0V ~ 20.75V
B7 yellow wire(the seventh wire) 21.6V ~ 24.90V
B8 yellow wire(the eighth wire) 25.2V ~ 29.05V
B9 yellow wire(the ninth wire) 28.8V ~ 33.20V
B10 black wire (the tenth wire) 32.4V ~ 37.35V
If the voltages are normal,all cells are okay.

Incidentally, 32.4V~37.35V + 3.6V~4.15V = 36V~41.5V

Then, measure voltage of the battery
without BMS (B- and battery anode) 36V~41.5V
with BMS (D- and battery anode) 36V~41.5V
If these two voltages are the same, then the battery pack is okay.

Note:If the voltage of any cell is more than 4.2V.I think the cell is overcharge.It can stop BMS and battery work.So you should find out which cell is over charged.