Battery Left Widget - FAQ
What does this app do?
batteries do not discharge linearly. That is, it probably takes much less time to drain from 100% to 90% than it does to drain from 30% to 20% under the same load.
Whilst the system battery % reading is a good reading of how much power is left in your battery, this non-linear discharge means that it can not be used to estimate the actual amount of time left on your battery.
Battery Left addresses this by using complex algorithms to monitor the usage of your phone so it can determine the linear discharge of your battery and therefore gives you an accurate representation of the time left before your battery goes flat.
How does it work?
Without getting into the technical details, the app watches for changes in the system battery level and calibrates itself using those. This calibration is actually continuous. Even when it's got an accurate representation of your battery usage it will keep logging these changes so it can adapt to any changes in your use of your phone.
How do I calibrate it?
The quickest way is to charge your phone fully (leave it on charge for a few hours after it reports the battery is at 100%) then use it normally until the battery goes completely flat and the phone turns off.
Generally, just using your phone normally will eventually give accurate readings, but if the app can get the full spectrum from 100% to 0% it'll give accurate readings much quicker.
What does it all mean?
- Full battery life - the hh:mm that your battery will last on a full charge
- Time left - the hh:mm countdown until your battery is completely empty
- Time dead - that actual time (eg 3.24pm) that your battery will totally run out
- System % - the % charge left as reported by your phone
- Estimated % - the % charge left as estimated by Battery Left based on time/discharge readings
- Estimated mV % - the % charge left as estimated by Battery left based on mV readings
Why are the estimated and system % values different?
This is normal and expected. The system % does not discharge linearly, yet the estimated % does. For this reason, your 100% and 0% readings should be in sync but the values along the discharge period will be different. Don't be alarmed - Battery left is designed to work this way.
What's all this about Seidio batteries?
Seidio manufacturer extended life batteries for many Android (and other) phones. There are known issues with Android firmware where some phones (particularly Motorola Droid/Milestone) can't properly gauge battery level. Users will see the battery level go rapidly down to 5% where it will stay for the majority of the battery life.
As long as Battery Left has the full 100% - 0% spread of readings, it should be able to give an accurate % left of your Seidio battery.
What are mV/voltage readings?
The mV that the battery supplies drops over the charge life of the battery. Battery Left takes mV readings at 100% and 0% and attempts to estimate the battery level based on these readings.
Where have the "Calibration" and "Stop calibration when accurate" preferences gone?
These are now under the batteries tab - just click the Edit button from this tab and you'll see them there.
Why does it require internet & phone call permissions?
The app ONLY connects to the internet if you select SEND DATA from the app (and even then it gives you the option to cancel). At this point it gathers calibration data and the settings you made in this app ONLY. it also gathers some ANONYMOUS phone information such as phone manufacturer, name, OS version etc which helps be look into any problems which is why it asks for "Phone Call" permissions - although this is really a misnomer as I don't ask for any information about any phone calls. I have no way of tying this data back to any individual phone or person, email address, phone number or anything along those lines. This is why the app reports the ID which you must tell me if you want me to look into a specific report. The app is also unable to make any calls or send any texts etc.
This app is NOT spyware, malware or anything along those lines.