Hi!

I'm testing battery life on an ESP32-C3 T-OI version 1.3 board.
Using MQTT I send two constant values ​​and the battery voltage to Thingspeak. The battery is a 700 mAh MOTOMA.
With a Micropython program using umqtt.simple and QoS=1 that takes about 5 seconds to connect and send the data and then goes into deepsleep for an hour, the maximum battery life is about 17 hours. The final voltage of the battery is 3.5 volts.

Has anyone done similar tests to find out if this is correct?
It seems to me that the battery life is very short, as if there is some part of the circuit with a high consumption during deepsleep.

Thankfully,
Ernesto.

@teastain2 Thank you!

Am I interpreting the schematic correctly and is the voltage calculation also correct?

Thankfully,
Ernesto.

Hi

I'm working on a project where I need to know the charge level of the battery mounted in the ESP32-C3 T-OI Plus (Ver 1.3).
From what I see on the schematic, Vbat is connected to the ADC input through a resistive divider made up of two 100K resistors that cut the voltage in half.

Building on that assumption, I'm using the following Micropython code:

...
#adc
a0 = 2

conversorAD = ADC (Pin(a0))
conversorAD.width (ADC.WIDTH_12BIT)
conversorAD.atten(ADC.ATTN_11DB)
...
def leerBateria ():
#Reads the battery charge percentage
batVolt = 2*(conversorAD.read_uv ()/1000000)
if (batVolt > 4.2):
batVolt=4.2
return (100*(batVolt/4.2))

I think it is correct because it reads values ​​consistent with the battery voltage measured with a multimeter.
What catches my attention is the variability of the values ​​read, for example if I read every 20 seconds I can have (with USB connected)

Bat = 99.57
Bat = 98.67
Bat = 99.57
Bat = 100.00

What could this variation be due to?

Thankfully,
Ernesto.

Hi!
I would like to know if version 1.3 of the board has an internal antenna

Thankfully,
Ernesto