How accurate are AccuBattery and Electron apps?

[The Penguin]

I own a Xiaomi POCO F3 and I've been keeping track of the battery health information using the AccuBattery and Electron apps by making an Excel document with all the data but some information doesn't make sense. How is it possible that on october 9th I charged my phone until 85% and I had a battery capacity estimate of 4 320 mAh then I unninstalled the app, didn't use it for 2 days, reinstalled it, and on october 12th it was 4 295 mAh and on october 13th it was 4 240 mAh. Doesn't make any sense. I also charged it until 100% on the 10/11 october and used the Electron app to check the real battery capacity and it was 4 490 mAh (remember that the POCO F3 has 4 520 mAh of real battery capacity). Today I charged it again until 100% and it was 4 368 mAh on Electron and 4 303 mAh on AccuBattery. How is it possible that the battery health degraded or lost that capactity in just 3/4 days?

Another example: on october 9th I charged it until 85% and the estimate battery capacity was 4 320 mAh (like I said above). Today with 100% charge it was 4 303 mAh.

Honestly I think it's impossible so I ask: how accurate is this data? And also note that I only have this phone for 7 weeks.

 

[LOLO9393]

I own a Xiaomi POCO F3 and I've been keeping track of the battery health information using the AccuBattery and Electron apps by making an Excel document with all the data but some information doesn't make sense. How is it possible that on october 9th I charged my phone until 85% and I had a battery capacity estimate of 4 320 mAh then I unninstalled the app, didn't use it for 2 days, reinstalled it, and on october 12th it was 4 295 mAh and on october 13th it was 4 240 mAh. Doesn't make any sense. I also charged it until 100% on the 10/11 october and used the Electron app to check the real battery capacity and it was 4 490 mAh (remember that the POCO F3 has 4 520 mAh of real battery capacity). Today I charged it again until 100% and it was 4 368 mAh on Electron and 4 303 mAh on AccuBattery. How is it possible that the battery health degraded or lost that capactity in just 3/4 days?

Another example: on october 9th I charged it until 85% and the estimate battery capacity was 4 320 mAh (like I said above). Today with 100% charge it was 4 303 mAh.

Honestly I think it's impossible so I ask: how accurate is this data? And also note that I only have this phone for 7 weeks.

View attachment 39230

This tool like many other are absolutely "approximate" stating from the simple electrical basis:
- It is not possible to quantify battery energy (mAh or Coulomb) by only sensing the voltage.
Anyway we are lucky this mean give a usable result for charge and discharge value.