battery life

All posts tagged battery life

Using a Phone on the PCT

You’re ready to hit the trail, your fully-loaded smartphone in hand. But how long will it last when you’re nowhere near an electrical outlet? I decided to find out by testing various conditions with two of the most popular smartphone models: iPhone 6+ and a Samsung Galaxy S5. I tested these models’ battery life with and without the use of a supplemental Ravpower 3,000 mAh and 10,400 mAh external battery pack. The test results conformed to the phones’ and battery packs’ published specs. With that knowledge in hand, I feel comfortable calculating expected battery life of other phones based upon their published specs.

External batteries I used for the tests:

I chose these Ravpower models because they are inexpensive, lightweight, and have a good reputation for reliability.

If you follow these simple steps, you have a good chance that your phone will have power between opportunities to recharge (a note of caution: devices fail — you should NEVER rely solely upon an electronic device as a navigation aid):

  • Keep your phone on airplane mode during the day when not in use
  • Turn your phone completely off while you’re sleeping
  • Do not use your phone for high-battery use activities for more than 2-6 hours per day:
    • GPS use
    • Internet browsing
    • Phone calls
  • Carry an external battery backup, size depending upon how long you expect to hike between town stops and how much you plan on using your device (see charts below)

Reality check: these results closely match my actual experience hiking the PCT with a smartphone and external battery backup.

NUMBER OF DAYS OF PHONE USE UNDER VARIOUS CONDITIONS

Phone Model # days,
no battery/
minimal use*
# days,
no battery/
typical use**
# days,
3000 mAh/
minimal use
# days,
3000 mAh/
typical use
# days,
10400 mAh/
minimal use
# days,
10400 mAh/
typical use
iPhone 6+  8.3  3.6  13.0  6.0  31.8  14.2
iPhone 6  5.0  2.1  9.9  4.4  28.1  12.2
iPhone 5s 3.9  1.6  8.4  3.5  24.8  10.1
iPhone 5 3.2  1.3  7.2  3.0  21.8  8.7
Samsung S5  7.6  3.2  12.1  5.4  30.0  13.0
Samsung S4  6.2  2.6  10.2  4.6  25.8  11.1
Samsung S3  5.4  2.1  12.0  4.8  35.7  13.8

*minimal use: 2 hours high-battery usage + airplane mode 14 hours + device off 8 hours
**typical use: 6 hours high-battery usage (GPS on/internet use/phone call) + airplane mode 10 hours + device off 8 hours

Minimal Use Chart

Typical Use Chart

  • It takes about 5 hours to recharge a 100% drained 3000 mAh external battery from an electrical outlet.
  • It takes about 6.5 hours to recharge a 100% drained 10400 mAh external battery from an electrical outlet.

Other Power Saving Tips: (Updated based upon reader comments)

  • Turn the phone completely off (or at least put it in airplane mode) while charging it from the external battery or you can accidentally drain both the phone and the battery!
  • Turn off your cellular data, Bluetooth, GPS and WiFi when not in use.
  • Reduce display &  brightness to a minimal level.  A brighter screen uses a lot more power than a dim screen.
  • Use a dark background (wallpaper) on your screen.  A bright white background uses more power than a dark background.
  • Set your screen timeout to the shortest possible time.
  • Turn off the phone vibration function.
  • Do not leave apps running when not in use.
  • Keep your phone warm to prevent battery drain (e.g. put it in your sleeping bag at night)
  • Android users: carry an extra device battery rather than a heavier external battery