Measuring the voltage and current of the charging LiPo battery

Hi,
I would like to do a project to monitor my charging Li-Po battery over the time. The battery will be charged by PV cells with the use of Genasun MPPT. Is there any way to measure the voltage and current of the battery during charging with the use of voltage sensor, current sensor and Arduino UNO.

Thank you so much for the help.

Measuring the voltage during charging is doable. I don’t know the exact process of charging the cells You use but in general the voltage is higher during charging and it can’t be compared with the cell voltage during idle nor in discharge.
Trying to measure the current during charging can’t be recommended. It might influence the charging and wouldn’t be good.

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I have 30Watts of solar feeding into a PWM controller to a 12V LiFoPo4 16Ah battery. I have, on the + of the battery a Gikfun 20A Range Current Sensor ACS712 Module and a voltage divider off the battery to measure voltage. Works well. Will need a Multi Meter to calibrate the current and voltage readings.

I used a 100K, R1, and a 10K, R2 variable resistor to set up the voltage divider. By using 2 variable pots, I was able to setup a voltage measurement range of good accuracy.

Try placing the current sensor in front of the battery charging control circuits. Then when measuring subtract the idle current from your reading and you should be close. A lot of this depends on your circuit.

Hi, do u mind to provide your circuit diagram ?

The ACS712 is a 5volt only device, and will have zero current drift and bad resolution.
An INA226 breakout board could have been a better match for your ESP32.
Leo…

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Measuring the current/voltage is, along with a few other things, is still a work in progress. I will check out the INA226 and check it out, thanks for the suggestion.


This is my circuit to measure the battery and I wonder does it work? Is there any problem in my circuit ?

The connection should go from the MPPT to the + of the battery and the connection for the INA169 should be between the battery and the load.

An INA169 is uni-directional (one way current sense), relies on the 10-bit A/D of the Uno, and has no voltage sensor.

An INA226 is bi-directional, has a built-in 16-bit A/D (I2C) for current and voltage, and more.

The only advantage of the INA169 over the INA226 is battery stack voltage.
Leo…

Coolies, got 2 on order.

Can add an external shunt to the internal 0.1ohm shunt if a larger current range is required.
Leo…

Hi, so that means I can just use INA226 to measure the current and voltage of the battery over the time ?

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