Using nPM Fuel Gauge board for battery capacity testing?

[aacosta]

Hi,

Is there a way to use the nPM Fuel Gauge board for battery capacity testing? I would like to evaluate/confirm the actual capacity of the batteries I buy.

The Power Up tool doesn't seem to provide a way to do this through profiling. Maybe I can infer this information from the raw profile files? If so, is the format of the files document somwhere?

[ketiljo]

When you profile a battery using PowerUP you will get the real capacity of the battery. Once the profiling has completed it will show xxxmAh consumed, which is the real capacity.

If you load the generated battery model in PowerUP the capacity will be shown in (): MyBatModel(xxxmAh)

[ketiljo]

Be aware that there are some limitations: 

The PowerUP tool, during the battery profiling process, calculates the discharged capacity (in ampere-hours) based on the unique discharge sequence configured in the nPM PowerUP App. This value represents the capacity that will be used by the fuel gauge algorithm. Even though it can be a good reflection of the battery capacity,  it should not be considered the actual, true capacity of the battery.

 The capacity reported during profiling may differ from the manufacturer's specified capacity, as it depends on the discharge rate and conditions used in the profiling process. 

 Manufacturers typically specify the nominal battery capacity based on a standard discharge rate and temperature, which you can find in the battery's datasheet.

[aacosta]

That's great! I wanted to confirm before buying the kit and the youtube videos didn't show it. Is it possible to see the discharge curve of the battery?

[ketiljo]

You can plot the discharge measurement data recorded during the profiling process, which is used to create the battery model.

A CSV file is available for each temperature and is saved in the project folder you select. It contains all the discharge data, including: Time, Current (A), Voltage (V), and Temperature (°C). This can be used to plot the curve in Excel for instance.