Multiple chargers to prevent imbalances?

clupton

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Aug 24, 2018
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45
Another newb question...

I am curious what you guys think of this. Say you have a 4S-10Ppack for example. Could you use 4 CC-CV Buck Converters to charge the pack by hooking up one converter to each parallel group of cells?

I'm just thinking that CC-CV Buck Converters are pretty cheap. Even if you got 4 of them that could be less than the cost of a regular charge controller combined with a BMS.

Thoughts?
 

Riplash

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May 27, 2018
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66
Yes that is possible. But you have to watch out for ground loops, and/or make sure each power source for the boost or buckconverter is isolated. If it isn't isolated or you have a bad ground loop you will have a short circuit and various parts will get hot, smoke, burn, or melt.

I have used a TP4056 to top off a low cell block in a 4SX40p, when the whole battery pack is being charged by aBoost converter. And I am planning on making an Arduino based active charger/bms using this concept.

-Ryan
 

clupton

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Aug 24, 2018
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45
I believe I understand. So I could not use the same power source for each buck converter. That adds some complexity. But if it were solar I guess each buck converter could get power from a dedicated solar panel.

I like the idea of charging each group to full capacity and not bleeding away excess charge in a BMS. But it may just be easier to use a BMS.
 

Korishan

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Jan 7, 2017
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Yep, they need to be totally isolated from each other. You could either use a DC isolator (not very cheap), or use a separate wall wart type charger for each, or use a transformer from AC mains to the needed voltage of the chargers. Then rectify all the outputs.
 

Charly144

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Nov 22, 2017
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daromer

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Its often just easier to do 1 charger or psus and a decent BMS that does balancing when you want. It is also roughly same price
 
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