3A LiFePo4 balancer / charger

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1

I am planning to build a 4S LiFePo-Powerbank. LiFePo4 are "selfsafe" in the sense of that they do not catch fire when overcharging or damaging them.

So I explicitly want a LiFePo4 charger/balancer which is something very different
than a Lithium or a lithium-polymer-battery

The batteries will have 6000 mAh per cell. So charge-current is 1A to 3A.
Discharge current is in the same range. This means a rather small batterie-management-system (in short BMS) will do.
So far I have only found this

To me the balancing current of 58 mA seems to be very small.
As far as I undestand balancing it is for equalising the voltages to the (almost) same level.
To protect cells that already reached their "full voltage" a current is bypassing the cell.
If this current is pretty small charging the cells that have not yet reached their final voltage will take a long time.

But maybe I am wrong. If somebody knows how it exactly works
or
If somebody knows a link to a LiFePo4-balancer
I would be very thankful for posting the info / the link

best regards Stefan

2

Look at the charger's current profile.
It should reduce charging current when battery voltage is nearly there.
For a LiPo, that current is linearly reduced between 4volt and 4.2volt.
For a LiFePo4 that could be between 3.5 and 3.65volt.
So at 3.6volt there is little charging current, and your board might be able to handle that.
Look at "active balancers" if you want more equalising current.
Leo..

3

I suspect that is not a problem, as the balancer element should not be activated until the cell voltage reaches some predefined level close to that expected for full charge. Try it and let us know what you find.

4

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