Battery Percentage - Getting An Accurate Test On Any iPhone

Question

Hello all,

I am looking for a way to run an accurate test on an iPhone and find how long it takes for battery percentage to drop. While considering this I thought

1. Would the temperature of the battery make a difference to my result i.e If I took my iPhone outside and ran the test would it be consistent with the test I ran indoors?

2. Does the percentage left in the battery when the test is run make a difference i.e Would the battery percentage drop faster if the test was run at 30% when compared with 95%?

My goal is a test which I can run on my device and get the same result (or near enough) every time the app is run.

I have the app logic working, this was just a last thought. Is there any code I could use to factor in the above problems and iron out my inconsistencies? Possibly find the temperature of the battery and do something with this?

Many thanks in advance,

Stuart

Answer 1

1. Yes, the temperature could play a role in how fast the battery drains. See: http://chemistry.about.com/od/howthingsworkfaqs/f/coldbattery.htm

2. Yes, the amount of battery life left does affect how fast the battery drains. It takes much less time to charge a battery to 65% than it does to charge it from 65% to 100%. The same thing happens with discharging.

Answer 2

The IPhone has a lithium ion battery. There will certainly be technical literature on the web which describes test conditions for such batteries.