All posts by Paul Bodnar

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.


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


Is it too early for 2015 PCT hikers to make a High Sierra hiking plan? Probably. We took a look at historic High Sierra snow pack data, as gathered by the California Department of Water Resources  (Station ID: BGH) at Bighorn Plateau. The snow depth at the Bighorn Plateau station (Google map) has been measured since 1949.

The chart below plots snow depth each year from 1990 to February 2015. You will see 4 bars in each group (except 1996, which is missing March data), representing the snow depth in February, March, April and May for that year.

Sierra Historic Snow Pack

Although February snow level tends to be a decent predictor of May snow, you should notice that you cannot reliably predict the May snow level based upon the February data. Just take a look at 1991 and 2013 to convince yourself of that.

So far 2015 looks like it may be a low snow year, but it’s too early to tell.

For your entertainment, here is all data, from 1949, taken from the Bighorn Plateau station. If you tackled the High Sierra in 1983 or any of the other big snow years, it would be interesting to hear from you in the comments.

Sierra Snow Pack 1949-2015


Paul (“Tangent”) here. After Guthook identified the steepest parts of the Appalachian Trail, Pacific Crest Trail, and Continental Divide Trail, I started wondering about the overall slope, or grade, of these trails. Using south to north elevation data at the tenth-mile level, I evaluated percentage slope from point to point, then binned the data according to various cut-off values.

All data is south to north.

Here are the results:

Percentage of CDT, PCT, AT with various slope values

As you can see, the AT has a greater overall percentage of “non-flat” hiking than the other two Triple Crown trails: 59% of the AT has a grade of at least 5% uphill or %5 downhill. Compare that to 53% for the PCT and 46% for the CDT.

A further analysis of the extremes shows that the PCT is very well-graded, with only about 2% of the trail at greater than a 15% grade uphill or downhill. The AT, on the other hand, is composed of 11% of extreme slope. That’s over 200 miles of some very tough hiking!

Percentage of PCT, CDT, AT with 15%+ slope uphill

Percentage of PCT, CDT, AT with 15%+ slope downhill

And for you data geeks, here is a scatter plot of the slope distribution for the three trails (multiply the x-axis by 100 for percentage values):

Slope Distribution for the CDT, PCT, and AT