I am running some battery driven powered temperature sensors in the house. Measuring the current with my multimeter shows that the Wemos D1 consumes 1.5 milli amps in deep sleep. I was expecting a tenth of that.

What am I doing wrong?

The battery is connected directly to 3.3V pin (and ground). the D0 is connected to RST to wake up after a certain time from deep sleep.

I measure the current with a multimeter.

  • 1
    \$\begingroup\$ Two things: the esp uses less in deepsleep, but the ldo and other peripherals will/can use more power. And measuring small currents with a multimeter is not trustworthy. The guy with the swiss accent (youtube) made a nice video about this. \$\endgroup\$
    – RemyHx
    Jan 21 at 22:53
  • \$\begingroup\$ yeah saw this video as well :-) he cut a wire with a scalpel \$\endgroup\$ Jan 22 at 20:30

1 Answer 1


Wemos D1 has several other components that are leaking power current.

  • CH340 via 3.3V power supply pin on it
  • ME6211 reverse leakage from 3.3V output of it

Reverse leakage current through ME6211 will be less than 100uA.

In theory, CH340's power consumption should be less than 0.5mA. but it depends on the quality of chip used.

  • \$\begingroup\$ Great! thanks for your response. Can I turn that CH340 off via software? I don't need it to measure temperature. \$\endgroup\$ Jan 22 at 6:13
  • \$\begingroup\$ you can't power down the ch340 from software. you might also have an LED going. There's also 10k pullups that leak on CHIP_EN, RST, GPIO0, and GPIO2 \$\endgroup\$
    – dandavis
    Jan 22 at 8:45

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