What is the difference between “active” balance and “passive”balance?

2021-11-01 19:13:09 Deligreen 1142

What is the difference between “active” balance and “passive”balance?

Some customers come to us and tell us their story:

I bought some prismatic lithium ion battery cells ,

but the batteries are unbalanced at the very beginning or after using some months.

The battery pack is 48V280AH.

The max volt is 3.286V, the min volt is 2.815VThe batteries voltage difference has 0.471V

How to solve the problem?

If replacing a new cell, the shipping fee is high and need to wait for a long time.And the new cell maybe not matches the current cells well.

If don’t replace it, he is worried and also the real capacity of the battery pack is lower than it is expected.


Then we advice him add Deligreencs active battery balancer.

Active balancing is also called “top balancing”.

The balancer transfer energy from the higher voltage cells to the lower ones.No loss of energy.Moreover ,

 the active balancer will balance all the cells at the same time.

Without balancer, people need to use a charger charge the cells individually and use a load or resistor to discharge the cell,

 and do the recycle one by one manually.This kind of top balancing  cost a lot of time and very slow.

While adding the balancers is like that you have employed a staff who work for you 24hours.

This stuff is smart and hard working! ;-D

The batteries are balanced gradually.



Some people will come up another question:

I have BMS with balance function. Do i still need the balancer? The BMS is passive balancing.

What is the difference?

Passive balancing uses the resistor to consume the power of the high-voltage battery. It is only suitable for small-capacity use,

and the balance current most are less than 200mA.While active balancing is up to 3000mA, which is 15times as high as passive balancing.

And passive balance cost is much lower than active.

Now let's sum up the passive and active balance differences as below:


Active balancing

Passive balancing

Balance current

Up to 3000mA

Up to 200mA







Power loss

No power loss


Balance result




passive balance.jpg

 if you check the photos above, i believe they can help you understand better about how active and passive balance work and what are their difference.

What customers say about Deligreen/QNBBM active balance? 

Deligreen Power

Deligreen Power

Deligreen Power



310AH unbalance solved.jpg

if you have any different opinion,welcome to discuss with us. 

And if you have any difficulty in your battery balance, please contact us freely,we will be glad to help you out!