DIY power pack charger with TP4056

Ivo Staelens

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Aug 21, 2017
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Yet another question:

Can the outputs of several TP4056 be put in parallel so that multiple TP4056's can charge a big cell.

For instance:

I want to build a powerpack 7s54p at +/- 3.3kWh

If I parallel 5 TP4056 per cell, so 35 TP4056 in total, I'd get 35A charging possibility.

The reason I'd like to consider this is price...

Those TP's are dirt cheap and this combined with a switching power supply 5V (found one 70A for 25) should make it possible to charge the batteries from a main plug.

In my opinion, using those TP4056's would balance the cells out too and would take care of the automatic cell charging. As the cells are charged separately, and the TP's stop charging if the cell is full, this seems like a perfect solution for me...

Is this a valid idea or not?
 
Yes in the parallel but the series would have to be isolated from the battery so you are charging the pack and not each cell. You might be better off using a buck/boost converter to set a max voltage for the pack.
 
The TP chargers will not all stop at the same time. Some will work harder than others, and some will work longer than others. The TP chargers are overall not that efficient. They are about 70% efficient.
If you want to charge a large parallel pack, you should look into getting the LM2596S Buck Converter. It can do up to about 3A output if the input voltage is 20V or more, and also about 95% efficient. Granted, it's not a standard lithium charger, but it does pretty well. Just set the output top voltage to 4.1V max and you won't need to worry about overcharging.
Those boards are also very inexpensive.

As jdeadman says, if you put any of those chargers in series connections, they have to have independent grounds. They must be completely isolated from each other. So, doing that would drastically increase the complexity of the whole rig.
It would ultimately be better to get a charger that can charge the whole string at system voltage instead of all the extra mucking around. Adding all those layers of complexity is also adding lots of points of failure and possible shorts. Not worth it in the end, IMHO.
 
Thx guys! That's because I ask. My in depth knowledge of electrics is not that good.

So I keep on searching and studying.
 
There are plenty of high current RC chargers out there. Check out AliExpress ect. Many 1000w+ chargers will take a reasonably high input voltage too. Increasing your efficacy.

In the long run the charger may cost a bit more, but in the long run you have a charger that has many other uses.

It does depend what power source you are going to use to charge your battery too.
 
so i have a hand full of the tp4056 so the LM2596S seem better for charging larger packs and not just single cells? Still working on my processing station and this seems a very nice upgrade! So this would be best for charging the large packs after they are built and tested?
 
Yes. The LM is for the larger packs. You still want to control it if you can to a degree for the CC/CV modes. But, for starting out, it would work out fine and you can expand functionality later on.
 
Korishan said:
Yes. The LM is for the larger packs. You still want to control it if you can to a degree for the CC/CV modes. But, for starting out, it would work out fine and you can expand functionality later on.

have to find out what you mean by the cc/cv? current constant/currnet variable?
 
constant current, constant voltage
 
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