Forums - Power Consumption at Different Battery Level

2 posts / 0 new
Last post
Power Consumption at Different Battery Level
zhaofukai0531
Join Date: 9 Nov 16
Posts: 1
Posted: Thu, 2017-10-12 01:15

When we tried to measure the power consumption on mobile device using Trepn, we found an interesting phenomena. We measured the power consumption for the same app at different battery level. The results showed that the power consumption tested at high battery level (for example 100%) is lower than the power consumption tested at low battery level (for example 60%). In the two test, we used the same app to do the completely same thing. But we got different power consumption at different battery level.

The following is the results tested on Hongmi2 device:

Low Battery Level Test:

Battery Remaining (%)  54.68888

Power [uW]  1778990

Duration : 23 min 26 sec

High Battery Level Test:

Battery Remaining [%]  96.47673156

Power [uW]  893661.1763

Duration : 24 min 40 sec

So, my question is : Is this power consumption normal? Is this phennomena the device's natural property?

  • Up0
  • Down0
ToolsPM
Join Date: 15 Feb 13
Posts: 393
Posted: Tue, 2017-12-12 14:35

I don't know this device, but most of the smartphones over the past few years DO NOT report accurate power. Some only report power data every 30 seconds, which makes power averages useless in most cases. 

Other devices don't report accurate power, so we estimate the power (and display an asterisk when we do so.) This data used to be fairly accurate BEFORE Google started blocking GPU and CPU load stats on Android 7.0 and beyond. So this is an issue with all newer devices. 

Qualcomm goes to great lengths to ensure that our battery fuel gauge software is accurate at all battery levels. This is not the case with some other OEMs (like MTK).

If you have a device that reports accurate power like a Nexus 6 or 7 and are NOT running Android 7.0 or later, you should not see any difference in accuracy at different battery levels. 

-Rick

  • Up0
  • Down0
or Register

Opinions expressed in the content posted here are the personal opinions of the original authors, and do not necessarily reflect those of Qualcomm Incorporated or its subsidiaries (“Qualcomm”). The content is provided for informational purposes only and is not meant to be an endorsement or representation by Qualcomm or any other party. This site may also provide links or references to non-Qualcomm sites and resources. Qualcomm makes no representations, warranties, or other commitments whatsoever about any non-Qualcomm sites or third-party resources that may be referenced, accessible from, or linked to this site.