I have a simple circuit with an Arduino board (load in the diagram) that I want to power using a solar cell via a TP4056 board. The 18560 Lipo battery is for powering the Arduino during night time. It seems if I disconnect the solar cell, the output terminals of the TP4056 goes to zero. I saw a similar thread on this issue and one answer said, the TP4056 is not designed to run a load.

  1. If that's true, then what would the purpose of the battery be?
  2. Does anyone have any idea why the output goes to zero when the input to the TP4056 (solar cell) is disconnected (or there is no light on the cell)?

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  • \$\begingroup\$ How about a link to the data sheet for the TP4056? \$\endgroup\$
    – Andy aka
    Jan 28, 2020 at 11:35
  • \$\begingroup\$ ...then what would the purpose of the battery be? The TP4056 is a battery charger IC. The TP4056 needs a battery to perform its function. You added a load but that isn't something that is supported by the TP4056. You could connect the load directly across the battery and that would work BUT you would then prevent the TP4056 from switching off when the battery is full and that means your battery will be overcharged. You don't want that. What you need is a module or IC that's specifically designed for your task. The TP4056 is not. \$\endgroup\$ Jan 28, 2020 at 12:04

1 Answer 1


The TPS4056 IC should be used only to charge the battery. When the battery is being charged the load should be isolated. If the load is connected, it will badly influence the battery charging cycle of TPS4056 and is definitely not recommended, even if it works.

  • \$\begingroup\$ Thank you for your response. I have heard that response before, but in my case the battery is fully charge (4V). That being said, why doesn't it power the load with no solar cell connected? \$\endgroup\$ Jan 28, 2020 at 12:01
  • \$\begingroup\$ I believe I have my answers. Thank you to all \$\endgroup\$ Jan 28, 2020 at 12:10
  • \$\begingroup\$ You should post the complete circuit. What is the load? Arduino needs 5V or 3.3V? Please show the load circuit as well \$\endgroup\$
    – User323693
    Jan 28, 2020 at 12:10

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