Have questions about FETS, transistors, measurement, power supplies, or anything else electrical?

User avatar
By kskbeko
#82436 Hi dear community;

I cant power up an ESP-01 with my 3.7v 1400 mAh Li-Po battery which could i fly drone.

İs there something wrong ?
i did measure the voltage and amps with a multimeter and i observe when i connect the pins Voltage drops to 1.4 but there is no drop when i connect them to a arduino's 3.3v. İs there a porblem with this battery ? or will all batteries behave like this ? where do i wrong ? what should i do for run it with a battery ?

Thanks in advance and best regards
User avatar
By QuickFix
#83021 The ESP needs a stable 3.3V±10% power supply capable of delivering at least 400mA (more or less), so the absolute maximum supply is 3.6V.
Normally, when a 3.7V LiPo is at full capacity, it's voltage level is at 4.2V (almost 1V over the nominal voltage of the ESP):

There are a lot of discussions on using different types of batteries (like LiPo) with the ESP, also on this forum; just do some (re) search on it. :idea:

In short: use a DC-DC convertor or a LDO (Low Drop-Out) regulator.
User avatar
By Bonzo
#83025 I use a similar battery in this project without a problem with a Nodemcu: https://www.esp8266.com/viewtopic.php?f=11&t=19802

I used a SMD LDO voltage regulator to save space with a couple of capacitors as recommended by the LDO specification.

Do you have a second battery you could try and see what voltage it outputs?