The Truth About LTE vs. Edge

Back in April we showed you how you could enable Edge on a Lumia 900. While options to change your cellular connection have been available on some WP handsets, AT&T typically made this option unavailable. So this was big news, and gave users hope that they could save some battery power when the high speeds offered by LTE were not required.

While I had great expectations for this test, the results have left me scratching my head. No idea what’s going on but let’s get down to the results and try to figure it out.

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 16%, or 2% per hour, battery drain in an overnight 8 hour test. 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 – I changed my cellular connection to E, or Edge, for the purposes of running this test. As you can see in the speed test results below (top two results) I was definitely running Edge. Btw, the lower result is running LTE).  The results: 100% at 1:00AM / 66% at 9:00AM – Difference of 34% or 4.25% per hour. Wait a minute. Isn’t Edge supposed to improve battery performance. Ok, I have seen anomalies before. Let’s try this again.

Test 2 – Same settings as above. The results:  100% at 12:31AM / 67% at 8:31AM – Difference of 33% or 4.13% per hour. I like consistency, but these tests appear to be consistently wrong. Let’s try another.

Test 3 – Same settings as above. The results: 100% at 1:18AM / 65% at 9:18AM – Difference of 35% or 4.38% per hour. I don’t get it. Three tests and three almost identical results. But results showing more than twice the battery drain of my baseline although Edge is supposed to be using less juice than LTE. I also noticed higher than average drain per hour during the day (5-5.5% per hour vs. 3.5-4%) with light usage.

Test 4 – This time I performed a soft reset just prior to starting the test. The results: 100% at 12:29AM / 93% at 8:29AM – Difference of 7% or 0.88% per hour.  When I woke my phone after 8 hours my Battery Meter app was still showing 100%, so my first thought  was that my phone froze overnight or the Background Task had become disabled. Then I noticed that Battery Meter was actually getting a reading every 10 minutes as it should, but I was still above the 90% threshold, where the L900 will not register a change in battery level. I had to run the L900s Diagnostics Tool to actually see what my current battery level was. But 7%. How is that even possible. Were the first three, very consistent, tests all anomalies, and this is the true result running Edge, even with a bunch of Background Tasks, email syncs, etc. Almost sounds too good to be true. Time to validate.

Test 5 – Same settings as above, but no soft reset before starting the test. The results: 100% at 12:31AM / 64% at 8:31AM – Difference of 36% or 4.5% per hour. Ok, what just happened. How do you go from 7% drain one night to 36% the next. A number very close to the first three tests.

I have a theory. When I rebooted my phone, Edge was able to find the closest tower and then work very efficiently. But when I went to work the next day and then came back home, Edge became totally confused, trying to connect to multiple towers, resulting in the abnormal drain from tests 1, 2 3 & 5. Or, after the reboot, Edge was off completely (unlikely) and although I did get a few emails overnight, they might have come through when WiFi turned on over 2 hours. Still very confusing. Maybe a few more nights of testing would help to prove this out, but the reality is that Edge is not configured to work efficiently on an L900. Might work just fine though on another device.

Seventh Truth -  While it is “possible” that using an Edge connection vs. LTE can conserve battery power, it may require additional steps like rebooting your phone each time you suspect that you are accessing a different tower. Without performing this extra step, using Edge could actually consume significantly more battery power. Proceed with caution young grasshoppers.

Time for some Wi-Fi goodness. Stay tuned.