Balancing LiPo?

Thread Starter

susannah

Joined Feb 14, 2010
87
For a single cell (3.7 volt LiPo battery) you don’t have to worry about balancing since the battery charger will automatically stop charging when the 100% charge voltage of 4.2 volts is reached.

Balancing is required however on any RC LiPo battery pack that has more than one cell since the charger can’t identify from different cells and know if one might be overcharged even though the total voltage of the pack indicates otherwise.
I have SparkFun 6000 mAh 1S 3.7V LiPo battery. It is made of 3 pc of 2000 mAh batteries.

Should i balance it?
 

Shagas

Joined May 13, 2013
804
Do you have a balancing charger which is capable of doing 3 cells?
If so then just always plug in the balancing plug when charging .

If you don't then use your voltmeter to check the individual cells on the balancing plug of the battery.
It's recommended that the cells be no further than 10mV apart . The less the better .
Concerning cells in parallel : Slight voltage difference between cells probably won't be an issue if you are trying to pull small amounts of current but if you try to pull currents close to max rated currents then you might be overloading some cells more than others because lipos have a low ESR which means that the cells with higher voltages would have to already be discharging alot of current before their voltage drops to the voltage of the lower voltage cells .
What this basically means is that you will be overloading the higher voltage cell/cells and overloading cells in lipos doesn't usually end well.

Please correct me if i'm wrong.

In general it's just better to keep lipo cell voltages as close as possible
 

ronv

Joined Nov 12, 2008
3,770
I think you only need to worry when the cells are in series (multiple of 3.7 volts) where one can be 4.4 volts and another 4.0 volts when the charger turns off. So one is over charged and the other not completely charged. Since his cells are in parallel both (or all 3) will always be the same voltage.
 

Thread Starter

susannah

Joined Feb 14, 2010
87
Do you have a balancing charger which is capable of doing 3 cells?
If so then just always plug in the balancing plug when charging .

If you don't then use your voltmeter to check the individual cells on the balancing plug of the battery.
It's recommended that the cells be no further than 10mV apart . The less the better .
Concerning cells in parallel : Slight voltage difference between cells probably won't be an issue if you are trying to pull small amounts of current but if you try to pull currents close to max rated currents then you might be overloading some cells more than others because lipos have a low ESR which means that the cells with higher voltages would have to already be discharging alot of current before their voltage drops to the voltage of the lower voltage cells .
What this basically means is that you will be overloading the higher voltage cell/cells and overloading cells in lipos doesn't usually end well.

Please correct me if i'm wrong.

In general it's just better to keep lipo cell voltages as close as possible
My quote in first post is from:
http://www.rchelicopterfun.com/rc-lipo-batteries.html

I don't have any balancer right now.
 
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