0
\$\begingroup\$

I bought few LiIon modules(TP4056, from eBay). Every module has 1.2kOhm resistor, so module will charge batteries(six in parallel) with maximum 1A. Because I have 42Wh power source, it'll take around 30 hours to charge from ~0% to 100%. So my idea is to use three TP4056 connected in parallel with batteries. Does it will work without blowing up batteries? Schematic is below(MT3608 is step-up booster). Batteries are from my old laptop's battery, they are without Protection. Also, I won't use TP4056's Protection. At best scenario, batteries will get 0.4A of current(2400mA divided by six batteries).

enter image description here

\$\endgroup\$
  • 1
    \$\begingroup\$ "Every module has 1.2kOhm resistor" what does that mean? I don't see your 1.2 kΩ anywhere in your circuit... \$\endgroup\$ – Marcus Müller Apr 23 '17 at 15:16
  • \$\begingroup\$ and: are you trying to build a bomb for self-harm? Because, this is how you build bombs (charging and decharging LiIon without protection circuitry) \$\endgroup\$ – Marcus Müller Apr 23 '17 at 15:17
  • \$\begingroup\$ @MarcusMüller 1.2kOhm resistor is on module(it limits how much current will flow through charging chip). No :D Charging modules will cut the power off at 4.2V. \$\endgroup\$ – SilvioCro Apr 23 '17 at 15:21
0
\$\begingroup\$

No. As its data sheet tells you in the first line, the TP4056 is designed to do one thing and one thing only: charge a single cell Li-ion battery. The 1k2 resistor allows you to change the charging current so you can safely charge a larger battery in the same time as a smaller one, but that's all you can do with it.

You can't combine its output with another output, which is something you can rarely do with any circuit that's not been specifically designed to allow you to do this. And you can't charge a battery at the same time as drawing power from it as you're showing in your diagram, because that's a physical impossibility. The charging circuit should be disconnected when you want to draw power from the battery (the TP4056 contains a blocking diode so that you can leave it connected to the battery and just remove the USB plug), and the reason for this is that the charger controls and monitors both the charge current and voltage in order to charge the battery correctly and safely, and connecting anything apart from one battery gives the charger no way of knowing what load is down to the battery and what is down to the other device.

So if you want to charge six cells at once, use six TP4056s, they cost peanuts compared to the batteries themselves. And make sure your power supply and connectors can safely handle the maximum current, because a mini USB is going to struggle to cope with 6 Amps.

\$\endgroup\$
  • \$\begingroup\$ Thanks for reply! Then I need six sockets at my wall? I missed switch, I never charge, and discharge batteries at same time. Any suggestion for charging module that can charge six batteries at same time with more than one amp? I'm space-constrained, and little bit price-constrained. \$\endgroup\$ – SilvioCro Apr 23 '17 at 18:13
  • \$\begingroup\$ You can use one supply to power all six TP4056s as long as it can supply enough current - the solder points either size of the USB socket are there to allow you to connect them together. It's the outputs you can't connect together. \$\endgroup\$ – Finbarr Apr 23 '17 at 18:20
  • \$\begingroup\$ I can provide 2.4A. What will happend with batteries if I leave them with single TP4056? \$\endgroup\$ – SilvioCro Apr 23 '17 at 18:28
  • \$\begingroup\$ If your supply can only provide 2.4A then you can only charge two batteries at once with 1A each. Use three supplies or charge two at a time. \$\endgroup\$ – Finbarr Apr 23 '17 at 18:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.