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Lipo battery with 3.7V1800mah 2amp output current which is not working with ESP32

Heena09

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Hello all,

I am design one PCB for Esp32 Ble application and i connected Esp32 with lipo battery of 3.7V 500mah 1 amp . Which actually work perfectly fine but for only 3 hrs.
So i replace it it with Lipo 3.7V 1800mAh 2amp output battery. Somehow with this battery ESP is not working.

I add 3.3Ohm resistor in series of Battery positive side to drop down its voltage also still its not working.

I also tried to use 3 Lipo battery s of 3.7V 500mah in parallel to enhance mah to 1500 mah. and than connect to my pcb of ESP 32 and its working perfectly fine .

I am so much confused about it why this direct LIPO 3.7V 1800mah battery is not powering up ESP32.

Here are the link of that 2 lipo battery.
 

KlausST

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Hi,

please show a photo (100kBytes should be sufficient) of the complete power supply wiring and it´s modules.
Do you have a scope to measure the ESP32 supply voltage?

Klaus
 

Heena09

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Hi,

please show a photo (100kBytes should be sufficient) of the complete power supply wiring and it´s modules.
Do you have a scope to measure the ESP32 supply voltage?

Klaus

Hello sir,

Yes i measured it . its 3.4V supply to the ESP32 which is enough for working.
 

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Heena09

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ESP32 can take from microamps to about 300mA so a resistor to drop the voltage is not a good solution and above 3.6V can permanently damage it.

Brian.
Hey Brain ,

I understand your point.

how can i used this Lipo battery of 3.7V 1800 mAh with my ESP32 instead of 500mAh. ?
 

KlausST

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Hi,

again. Please confirm.
* did you use a scope?
* Did yo measure directly at the ESP32? (not battery or somewhere else)

I see no bulk capacitor on your PCB. Something like 100uF Tantalum...

Klaus
--- Updated ---

added:

A LiPo battery voltage can be from 3.2V up to 4.2V.
4.2V surely is out of specification for the ESP32.

So the ESP32 voltalge needs to be below 3.6V for healthy operation. Recommended: 3.3V.

On the other hand you need to switch off the load from the battery when the battery voltage drops below 3.2V (may differ from type to type). Otherwise you risk to permanent damage of the battery caused by under discharge.

The clean soultion is a 3.2V...4.2V (plus safety margins) input --> 3.3V output buck-boost switch mode supply.
..with undervoltage protection.

Klaus
 
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betwixt

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Or the 'dirty' fix is to add a Schottky diode in series with the battery, it should drop a fairly constant 0.5V or so. You should follow the ESP32 data sheet and add a large value capacitor across the supply pins as Klaus suggested, without it and a regulated power source you risk it crashing as the Wifi transmitter starts running.

My experience with ESP32, and I use quite a few, is that if the supply voltage drops too low (about 2.5V) they crash and the transmitter tends to turn on by itself and current consumption shoots upward. It doesn't do any damage but if the voltage is then raised back up to 3.3V and if you don't reset it, the transmitter will continue to run and current consumption will remain high.

Brian.
 

Heena09

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Or the 'dirty' fix is to add a Schottky diode in series with the battery, it should drop a fairly constant 0.5V or so. You should follow the ESP32 data sheet and add a large value capacitor across the supply pins as Klaus suggested, without it and a regulated power source you risk it crashing as the Wifi transmitter starts running.

My experience with ESP32, and I use quite a few, is that if the supply voltage drops too low (about 2.5V) they crash and the transmitter tends to turn on by itself and current consumption shoots upward. It doesn't do any damage but if the voltage is then raised back up to 3.3V and if you don't reset it, the transmitter will continue to run and current consumption will remain high.

Brian.
Hey Brain ,


I will do both the option and i did not observe it on scope.

I will try Schottky Diode and also follow the ESP32 datasheet for the high value capacitor.

Thanks to Klaus for your suggestions.
 

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