Leafmotor

Each motor controller has min cut off voltage and max working voltage.

For example:
48v Controller’s cut off at 40v. Less than 40v, not work.
36v Controller’s cut off at 30v. Less than 30v, not work.

For 48v electric bike motor kit system.We recommend reach set cut off voltage to over 42v by LCD. Less than 42v,should charge battery. It’s good for battery.

These days,all kinds of lithium batteries was made by 13 series connection or 14 series connection cells to be 48v, 52v.

Each cell – min about 2.8v , max about 4.2v
13 series – 4.2v x 13 = 54.6v
14 series – 4.2v x 14 = 58.8v

Overdischarge and overcharge both Not good for battery.
For example: if set it to 40v (controller’s cut off voltage is 40v)

2.8 x 14 = 39.2v (about 40v)

If 14 series connection cells ‘s min voltage to be 2.8v at the same time. That’s good.

But ride half a year, cut off voltage still 40v.
If No. one cell ‘s min voltage is 2.7v, second is 2.9v, third cell is 2.9v….
Total voltage is 40.4v ( 2.9 x 13 + 2.7v)

If first cell’s voltage to be 2.7v, it’s overdischarge, battery can’t to be charged. Battery is broken.
So we recommend charge battery when it reach about 42v or over.

If min 42v
No. one cell ‘s min voltage is 2.9v, second is 3.0v, third cell is 3.0v….
Total voltage is 41.9 v ( 3.0 x 13 + 2.9v)

New battery doesn’t have this issue. If ride 1-2 month, we recommend charge battery @ 42v or over.

For example: cell phone, only leave 20%,need to charge. If use out all that will break cells, also very hard to charge.

So we recommend set cut off voltage by LCD that over controller’s cut off voltage.