Think the “push email” myth was pretty well busted here a while back. This time up, we taka a look at email in general. It’s been a busy few weeks in the Microsoft/WP world, with the introduction of the Microsoft Surface Tablet, the unveiling of WP8. And, oh yeah, another firmware update for the Lumia 900 from Nokia. That update brought some tweaks to an already awesome phone, but also introduced a little glitch, at least for me. Since the update, L900s will no longer display battery percent remaining in the Battery Saver (or my homebrew Battery Meter app) applet, between 100% and 91%. So, after a full charge your phone will remain at 100% till it reaches 90% and then drop in 1% increments after that. Still don’t know if this is a feature or bug, but it has changed the way I do my battery testing.
I actually started this round of testing in early June, but decided to throw out all the results pre-firmware update as they couldn’t be compared to post-firmware update data. Add a few, “we need you in early today” days, plus an overextended stay by a relative, and a four day test took closer to three weeks. Oh well.
I could have predicted the results of this test but needed to see it through, just to be sure. In previous testing, I would charge my phone to 100% and then use it till it dropped to 99% , indicating to me that it was no longer topped off. With the recent firmware change that’s no longer possible. So I am now starting my tests fresh off the charger and presumably at 100% (your phone will cycle from 98% / 100% to keep the battery from overcharging). As this is in no way an exact science, there are going to be variables. That’s why I repeat all of my tests at least twice, looking for consistency, or at least a fair average.
To recap, my phone (Lumia 900) is setup with the following:
Data (mostly LTE) and Wi-Fi ON – Bluetooth OFF
8 Active Background Tasks (3 Internal)
Location Services ON
5 Email accounts syncing (3 push, 1 every 15 minutes, 1 every 2 hours)
Phone set down and untouched for a 8 hour period
My previous baseline tests have resulted in an 18%, or 2.25% per hour, battery drain in an overnight 8 hour test. Because of of the firmware change I ran several “baseline” tests (with everything above turned on) and came up with 16%, 15% & 16%, so we are going to stick with 16%, or 2% battery drain per hour. Why the difference? I think the phone normally hung at 100% longer than it should have, hence the reason for me wanting to start my test at 99%. But it’s not a big deal. What we are looking for here is the difference between one scenario and another, not necessarily the actual numbers. For clarification, my Background Tasks include; USA Today, Fox News, Weather Channel, Mehdoh, Urban Dictionary, Network Dashboard, Clever-To-Do and Battery Meter (a homebrew app set to update every 10 minutes).
Test 1 – To prepare for the test I set all five of my email accounts to “manually”, charged my phone to 100%, unplugged it and set it down untouched for 8 hours. Results: 100% at 12:32AM – 87% at 8:34AM – Difference: 13%, or 1.63% per hour. About what I would have expected. A 3% drop over 8 hours, or 6% per average day. Let’s try this again.
Test 2 – Same setup as above. Results: 100% at 12:45AM – 88% at 8:45AM – Difference: 12% or 1.5% per hour. Ok, well that’s pretty close. They do say, three’s a charm though.
Test 3 – Same setup as above. Results: 100% at 12:08AM – 87% at 8:08AM – Difference: 13% or 1.63% per hour. That settles it; 3% drop every 8 hours. Note that as with most of my tests I did have a couple anomalies. Between two of these tests I had one night with a whopping 23% drop. And during my pre-firmware update tests, I had results of 13%, 22% and 24%. Nothing stood out on the tests that caused excess drain and all of the test parameters remained unchanged. The simple explanation would be AT&T playing around with LTE, but I do have another theory that I will be testing soon.
Fifth Truth – Having multiple email accounts (I have 5) syncing via “as items arrive” or a timed interval will use some battery through the course of the day. But no more than about 6% per day on average. IMHO not a bad tradeoff for the convenience of having your mail waiting for you. Note: if you receive hundreds of emails a day, your mileage may vary.
Next up; there is no shortage of rumors flying around regarding features and functions that steal your juice. One such rumor involved the standalone Facebook app. This won’t take too long. Promise. LTE vs. Edge after that. And one that has me curious; IE open tabs. More to follow.