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Phone Solar Chargers/Power Banks

Instead of lugging around my DSLR camera during backpacking trips I invested in a Samsung Note 20 phone for picture taking/phone/ offline navigation in one. Now I have a new problem keeping it charged!! It drains power so fast.  It only last a day maybe 2 on airplane mode. I would use a solar charger with 30000 mAhz in past but that only gives me maybe 2-3 charges after experimenting with the new phone. I need to keep it going for a whole week. I don't know how to keep it alive that long without plugging it in. Any advice?! 

11 Replies

In addition to airplane mode being on, make sure wifi is turned off. Otherwise your phone will be actively searching for wifi. Won’t make a huge difference but several small things will add up. 
Additionally, if your phone is set for auto-brightness, turn that off, too. Having it on will keep your phones camera active to adjust for light. 

And, of course, close down any unused apps. 
That said, no smart phone will last a week. You’ll definitely need a charging bank. 

I have the Anker Power Core+ and it’s 26800 mAh. It will easily give you a weeks worth of charging. Because my SatCom device pairs with my phone (Zoleo) I need a reliable power bank. 

“Between every two pine trees there is a door leading to a new way of life.” (John Muir)

Superusers do not speak on behalf of REI and may have received
one or more gifts or other benefits from the co-op.

Generally,  switching on "Airplane mode" automatically disables Wifi and Bluetooth and you have to turn them back on individually if want to use them in Airplane mode (ie with the phone service off).  A point to note is that airplane mode does not usually disable the phone's GPS probably have to disable Location services to de-power that if you wanted to but usually you want it on when backpacking for navigation purposes. least all the smart phones I have used work that way.

It is a good point that leaving wifi on where there is no wifi available uses power to scan for wifi (just like leaving the phone service on will scan for cell towers) but unless you go through town on your trip there is not generally a reason to switch wifi back on.   In town you likely will have phone service and possibly wifi and charging opportunities.  If so it's likely you will just to switch Airplane mode off so you can use your phone.   Bluetooth on the other hand is useful for communicating to other local devices like GPS's, Satellite messengers and ear buds so once in airplane mode you may want to switch it on and off as you need to use it.


First thing is that unless you have service and you need it,  you should switch you phone to "airplane" mode.  You can turn bluetooth and wifi back on on an as needed basis.  (Same for airplane mode if you want to see if you have phone service).   Also turn your phone off at night.  This will save a lot of power.

A 5000mAh battery bank...maybe also re-charging a headlamp and Garmin InReach as needed... can be good enough for a up to a week...ymmv.   10000mAh is generally plenty enough for most people.  A PD bank is best if you have a newer phone that supports it,  but mostly because charging the bank is a lot quicker.  Personally I have an older Anker 5000 pd bank which was plenty for a week with my Google Pixel 3a used as a still camera and occasional navigation.  I think there are newer versions.  Anker are generally a good bet.  The Nitecore 10000mAh is  another newer lightweight one (~5.5oz)  I have heard good things about.  As an aside, their NU25 is a good re-chargable headlamp or the NU20 if you want things simpler.  

If you have more camera needs of go out for longer than a week without a recharge you might need to go to a 20000mAh or bigger or carry multiple banks

Solar chargers while they work well in some places (eg out West in the summer) are generally not worth the weight and bother bakpacking unless you are out for a very long time (say > week) and will have no other way to charge anything.  I have a light weight lixada one (~3.5oz) with decent cells which will charge my Garmin mini and will put some power into the battery bank as an emergency backup and have yet to use it even on a 7 night trip.

There are stoves that actually charge you phones as well I believe Bio stove is who I’m thinking of. I personally just use 3 solar/110v battery banks 


Don't use your phone for navigation and carry standard topo maps that you know how to use.  Then you are not dependent upon batteries.

Superusers do not speak on behalf of REI and may have received
one or more gifts or other benefits from the co-op.

I agree with the other inputs but you should also assess your 30000mahz charger. Age tends to wear them down and they become much less effective.  Another recommendation is to charge your phone to 100%, use the setting recommendations below and see how long the onboard battery is good for.  You may have a defective new battery in the phone as well. Once you do the test, ask the sales person about performance drops and potential warranty issues...Good luck

Superusers do not speak on behalf of REI and may have received
one or more gifts or other benefits from the co-op.

I'm not familiar with that model of phone, but my phone has a place that tells me what apps are using the battery by percentage, over the last 24 hours or last ten days. If yours has this, you can find out what's draining your battery. 1-2 days on airplane mode seems pretty short. I use about 7-10 percent of my phone battery per day in airplane mode, but I use it pretty lightly. I take 10-20 pics, check my location with the gps maybe once an hour while hiking, turn it off airplane mode and send a few texts and check email each evening, turn the phone off at night. I never need additional power for less than 5 day trips. 

Superusers do not speak on behalf of REI and may have received
one or more gifts or other benefits from the co-op.

Sorry, I missed that you said you were having the problem in airplane mode. A quick search indicates the Note 20 is a bit of a power hog. Here's a link I found that may be useful.

While combined battery and solar charger seem like a good idea, the small panels they have are not that effective and not really worth the exta weight for backpacking. Often they are of variable quality and don't live up to their hype.

The lixada 10W solar panel I have is just a solar panel with a USB output on a 8*10  plastic board.  It has the more effcient solar panels and has at least twice the area of any combo bank.  Even so the lixada 10W panel cannot produce 10W as its name implies. The name comes from the max theoritical potential of the solar cells used. Even in the best light after conversion to USB you only get a fraction of that. At 3.5 oz it is almost worth it as an emergency backup but for general use it is not effective enough to bother with.

I saw a test of the Biolight and its an interesting idea but imo does not work well enough to be worth the weight for backpacking even assuming you can use a wood stove.  The main issue with it seems to be keeping it stoked so it can burn long enough to generate enough electrical power to be useful. 

I was researching some more into how long a 20000-30000 mAh solar chargers take to actually charge fully by the sun only. It was something ridiculous like 50-70 hours! How pointless! Why bother selling these things just stick with a standard power bank! I just bought an Anker 26800 power bank for both myself and my dad for the trip, which is about 1 pound.  I will no longer bother with those useless solar chargers. I think as long as I apply all cell power saving tricks I probably be Ok for a week. Also I was reading up on tricks to extending life of power bank especially those with quick charge plugs. Interestingly it was recommended to use the standard charge USB or micro on the power bank and not use the quick charge plug in to extend it's life since it exerts too much power at one time. Unless you need a quick charge of course. Looking forward to the future invention of light weight off grid power! All about trial and error right now!