Introduction
Battery packs, batteries and power banks (three names for the same thing) get used a lot.
A phone on airplane mode will last about four days on trail when used for navigation and taking pictures.
Headlamps and other tools (InReach gps, etc) will often last that long.
But sometimes you are more than four days between resupply and recharge and sometimes you need a recharge before four days.
In that case you need a battery bank. Which is why thru-hikers almost always carry one.
Which one is best
There are many brands out there but two have really made a name for themselves in backpacking: Anker and Nitecore. Not surprisingly they are also the two that perform the best.
Here are the recent benchmarks.
https://backpackinglight.com/anker-nitecore-portable-battery-charger-tests-batterybench/
In actual testing of batteries for the trail. Nitecore is lighter and has better energy yield. “Energy yield” is how much of a charge the battery actually delivers.
Anker is a bit more solid and the recall/warranty experience has been excellent.
Bottom line: Nitecore tends to perform better and weighs less. Anker is “more solid.”
What about solar options?
As for built in solar panels:
measured 1.8 Wh of energy added to the battery in two hours of winter noon direct sunlight. During June, it might charge twice as fast (but only with clear skies and no shade, and while always pointed in the optimal direction). Even under optimal summer conditions, it would take more than a week for an empty Anker PowerCore Solar 20000 to recharge fully.
Yep. They are not very useful.
On the other hand, for desert sections of trail, a separate panel paired with a battery works ok. I prefer two 10,000 mhA batteries (you can charge them faster, if one dies the other provides some redundancy) but a panel + battery works well.
Happy6 hiked that way for a while. I’ll note that trickle charge works on battery packs but most phones won’t recharge that way.
Hints for more effective use.
I tend to recharge my phone from 20% to 80% and not to leave it plugged in overnight. Plugging in overnight seems to waste power.
The benchmark tests agreed with my observations:
Overnight recharging an iPhone wasted a significant amount of energy on every PBC tested. It’s best to unplug your iPhone after a couple of hours.
Other notes
I’ve tried a number of batteries for various reasons.
I have, for example, a charger combined with battery. In use it weighed more than the two separately. I had it to reduce weight, not increase weight, so it is at the bottom of a gear drawer somewhere.
Another option is pass through charging (ie you can charge your battery at the same time you charge a device off the battery). That is useful. You can plug the battery into a recharger and your phone into the battery and not need to babysit them or switch what is plugged in.
Some have multiple types of USB styles ports. Etc. Others have built in cables.
Most options are weight without real benefit. That said, pass through is nice and doesn’t seem to add weight. Two tens are better than one twenty.
Be aware that power banks can fail. Even good ones. Be careful and treat them well. I always hike with mine in a zip lock and inside of my electronics/med kit dry bag.
A note on reviews
Too many reviews really just want you to click through and let them earn an affiliate marketing kickback. Often they don’t actually test or use all of the banks they review.
Instead of a “best” they will toss in lots of categories and often have statements like:
For options we did not test, we chose each power bank based on several key specs like battery capacity, connectivity, and power output.
That kind of statement means they didn’t actually test everything aqbut instead picked “trusted brands such as Anker, Mophie, and BioLite” and read specifications and tried to find reasons for you to click on one of the best selling brands you were likely to buy anyway.
On the other hand at least one reviewer was honest:
- Shortcut: Just buy the Nitecore NB10000 Gen 3. It is by far the best performer, and nothing else comes close
Cables
With the new USB cable standard (finally) most hikers can get by with one type of cable unless you have an old Apple or an old USB micro Android phone. (Don’t judge me).
For the Appalachian Trail I bought six inch cables to connect my charger to phones or batteries. That was perfect.
On the PCT I picked up a damaged cable out of a hiker box. There are many times a longer cable really is useful because of the way recharge power stations end up.
The CDT did not have the crowding and other issues but I’ve kept the longer cables (though I had to replace the one I got at the Shelter Cove hiker box).
Bottom Line
On the Appalachian Trail you will need one 10,000 mhA power bank. In the 100 mile wilderness you will need to be careful and stay in airplane mode almost all of it.
On the PCT you can get by with one as well. However, two will give you a level of safety and redundancy. I carried two most of the trail (I still have 250 miles left).
On the CDT two banks can be a good idea as well, though you can probably get by with one. I carried two for the first two thirds of it. This year when filling in the New Mexico gaps I carried one. Planned on just one for the Cirque before we were smoked out.
Generally if you are at five or more days between resupply then consider more than 10,000 mhA. In addition, if you shoot a lot of video or get online a lot then a little more power can’t hurt.
Finally, if you hike with a partner, a second bank gives you some redundancy.