I've been using a Nokia BL-5C 1020mAh, 3.7 Li-Ion battery to power up my SIM800l GSM module. Everytime I used the battery for testing out the various AT commands for maybe 30 mins or an hour, I'd check the voltage, and it'd still be at around 4.2 volts. Not much drain.... But the next day (overnight), the battery would be dead. At around 3 volts (Thanks to the overdischarge protection of the TP-4056). This happened a couple of times.

So I decided to check if the battery was leaking current when connected to the TP-4056 without any load connected to it.
And... I was right. Around 25mA!
Why could this be happening?
Is my TP-4056 module bad?

  • \$\begingroup\$ Perhaps you could add info, facts, data to the devices you refers to. \$\endgroup\$
    – MatsK
    Oct 9, 2017 at 18:01
  • \$\begingroup\$ There is only one kind of Nokia BL-5C and the TP-4056 module I have comes with over discharge protection and short circuit protection also \$\endgroup\$ Oct 9, 2017 at 18:05
  • \$\begingroup\$ It's up to you if you want help or not. \$\endgroup\$
    – MatsK
    Oct 9, 2017 at 19:08
  • \$\begingroup\$ Please post circuit schematics, images of your prototype and any other relevant information. \$\endgroup\$
    – MIL-SPEC
    Oct 31, 2018 at 16:25

2 Answers 2


The TP-4056 is rated to draw a maximum of 6 micro-amps in standby, so either the circuit is poorly implemented or something is defective.

(Ibat in standby mode on the datasheet)


Why could this be happening? Is my TP-4056 module bad?

My TP4056 was also doing same.
I used a new battery and tried changing switches.
Lastly I found the problem was with the TP4056 itself.
I exchanged it for a new one and voila. No more power drain.

As I had the same problem as you and as the replacement 4056 and almost all others do not have this problem it seems very likely that your 4056 is faulty.

  • \$\begingroup\$ This doesn't really appear to be an answer, but merely a statement that you had the same problem and wonder at the cause. \$\endgroup\$ Oct 10, 2020 at 3:39
  • \$\begingroup\$ Edited to focus on question. \$\endgroup\$
    – Russell McMahon
    Oct 10, 2020 at 5:56
  • \$\begingroup\$ To the future readers (from websearch) For a few aliexpress TP4056, I measured Ibat ~ 10uA, clearly over the spec, but not as bad as the original poster. Be aware. \$\endgroup\$ Sep 26, 2022 at 22:53

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