I am trying to set up a balance charger for 3S 11.1V LiPo battery using cheap components. I have a PC power supply and several TP4056 modules.

However, there seems to be something wrong with the circuit attached. I have noticed that everyone on youtube uses isolated power sources for each TP4056 module. Why is this? Does it apply even if my power source can handle enough wattage?

When I did this, the diode or transistors on the TP4056 closest to ground caught fire. I don't understand what's wrong about my reasoning.

Also, can I safely use these modules for charging 3.7V batteries even though they each output 4.2V?

My Layout (from a different Stack Exchange EE question)


1 Answer 1


No, you can't use the module to charge batteries in the same pack simultaneously with the same power supply. That will short out the batteries via the modules together.

The modules are meant to charge one cell only. Connecting them in parallel means shorting the battery cells as they are connected in series inside the pack but parallel at the power supply side.

And that is the reason why your modules burned up, and that is the reason why other people use isolated power sources to not burn anything up.

  • \$\begingroup\$ Do you know how I could isolate the output of my single power supply to create several of the same voltage? I have looked into the use of the b0505s-1w isolated dc-dc converter. Could this or something else work? \$\endgroup\$ Commented Apr 23, 2021 at 6:31
  • 2
    \$\begingroup\$ I think that should be another question then. But to me that sounds like working around the actual problem, why put money on three (or two) isolating converters for three wrong kind of battery chargers, if it was cheaper to have the right kind of charger to begin with. Besides those isolating modules can only provide 200mA max current. \$\endgroup\$
    – Justme
    Commented Apr 23, 2021 at 6:42

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