All posts tagged iphone

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


Over the past three years of working on Guthook’s Guides iPhone apps, I’ve had to teach myself everything coding from the first “Hello, World” app up to what you see today. It hasn’t been a smooth process, as any of you who have been using the apps all along can attest to, but if you’ve been using them since the beginning I think you’ll also agree that the apps have come a hell of a long way. The latest versions of the apps, released in March of this year, were really the first that I felt completely satisfied with, and here’s why.

Testing on every iDevice I can find.

Testing on every iDevice I can find.

There are many ways to measure apps in general. How stable is the app? How fast is it? Is the content worthwhile? Is there broad appeal? Is it easy to use? How much can be done within the app? The first two of those questions are technical in nature, and the others are more subjective based on the users. All of them combine into an important recipe, since the app could have high marks for all of those questions except one, and that one could destroy everything.

Stability and Speed
The part of the equation that can be measured most objectively is the part that I can deal with in a solid way. Every time one of my apps crashes, or every time an elevation profile takes more than a second to appear, I can’t stop thinking of how I can fix the problem. I lose more sleep than is reasonable over every glitch.

I use analytics tools to keep track of the number of times my apps are opened every day, how many crashes occur every day, and how much time is spent using the apps. Last year, there was one set of numbers that drove me crazy– approximately 300 app opens and 25 crashes per day, or 1 crash per 12 app opens. That’s a pretty high ratio. Totally unacceptable. By the beginning of this month, after constant bug-hunting, I whittled it down to 4 crashes and 400 app opens per day, bringing the ratio down to 1:100. By the end of the month, I expect the latest round of updates to reduce that by 75% more.

Looking at the loading times for the elevation profiles and maps shows a similar trend. The original elevation profiles that I introduced early in 2013 could take up to 15 seconds to load on my iPhone 4 for the Southern California PCT. By now, that same exact data set is loading on average in 0.8 seconds. This is good progress. Maybe in the future I’ll have that down to milliseconds.

Ease of Use and Strong Features
The original PCT apps were pretty basic– map, waypoints, and that’s it. Since then I’ve added trail registers, bulletin boards, elevation profiles, Facebook/Twitter sharing, storage management, in-app purchases, and auto-updating trail data. I’ll continue to add more features, but new features are only worth adding if people use them. Getting people to use new features is a lot harder than you’d expect.

The collective experience of thousands of app developers says that the vast majority of people won’t use features if they take more than a minute to understand. The same goes if a feature can’t be found. I’ve seen several trail guide apps that are so cluttered with buttons and menus and flashy features that I get confused and frustrated trying to figure out what the developers intended. Take the PocketRanger series of apps, which are guides to each state’s State Park system. I tried to use the Maine app to see what info was available for my local state park, and gave up after getting lost in a maze of menus, poorly marked buttons, and cluttered screens.

Every time I add a feature to my apps, I spend as much time making the feature work as finding a way for it to fit in with the rest of the app. The goal is to keep screens uncluttered, and the app simple enough to be easy to use. It would be an awful waste of time for me to create a new feature that nobody used, after all.

Worthwhile Content and Broad Appeal
As far as I can tell, most people buy my apps for the content, not the features. They use the features, of course, but the trail is foremost in their mind before purchasing. That’s why I started with the PCT and AT, which are two of the most popular long-distance hiking trails in the US. My partners at High Sierra Attitude and I are now working on broadening the appeal of the apps by enlisting local experts to make guides for more trails.

We’ve already started this with South Downs Way and the Continental Divide Trail, where we’ve partnered with people who already write guidebooks for those trails. We’re working on other partnerships like that, including one with the Pacific Northwest Trail Association, and a few others all over the country. I figure that having locals and experts create the content for apps while I focus on the technical programming side of things will make for the best possible guides.

I’ll keep working on all of this, and I hope you all are enjoying the efforts!