TP4056 both leds turned on and 18650


I'm using a TP4056 to charge a 18650 (branded Samsung, 2900 mAh) that powers a small DIY weather station.
The weather station is equipped with a MAX17043 that measures the charge of the battery, at the moment the station is not powered with solar panels but when the battery charge goes lower than 20% I disconnect it from the station and charge it separately with a TP4056 board and a 5V 3A power supply.
I'm doing this since february '21 and until a few weeks ago the blue led of the TP4056 turned on correctly at the end of charge (the MAX17043 measured 95/96%).
Now when I connect the battery, the red led correctly turns on but after about 3 hours the blue led turns on while the red one remains on.
The first time I disconnected the battery from the TP board and connected to the weather station: the measured charge was around at 80%.
Then I attached the battery to the TP again for 1 more hour but the both leds remained on, just a few hours ago I recharged the battery and this time the charge measured from the MAX17043 was 56% that turned to 60% after 30 mins.
Why that behaviour?
TP4056 board defective? Damaged battery?
Thank you, regards.


To me it looks like You do the same mistake as many beginners. You throw a lot of hardware in a sack, lacking knowledge, but thinking that shaking the sack will bring You a working system.
Do like this:
Break the project down in pieces. Let reading buttons be one part, exercising hardware the second part. When You master the parts You can start integrating them into a system.

What does the datasheet for the TP4056 say if both LEDs are on ?

I have several TP4056 boards and they are working fine. This is a very cheap board, if it stops working, just replace it and you will know the answer to your question.

@ Railroader: excuse me, I don't mean to be rude but...I didn't get the meaning of your reply...the problem is with a board and a battery, I don't see "a lot of hardware into a sack"...if you are referring to the "weather station", it is working exactly as I designed it and it's not that the subject of my question.

@ srnet: the datasheet reports that both leds turn on if the battery is disconnnected, to be precise the red led should blink but it's steady red's not clear why and I didn't find so many info about it on the net. The datasheet also mentions a "10uF capacitor" but I didn't understand if I should use it or not.
Lots of wiring schemes that I found don't use that capacitor.

@ boffin: I will try to replace that board...



The datasheet says that if you have 10 uF cap connected instead of a battery red LED will blink. Most boards have this capacitor.