Best way to charge your smartphone on multi-day walks ?

[AnthonyD]

Hi,

As one of many people who have switched to using a smartphone as their primary bushwalking GPS, I was wondering what people out there do to power their devices on multi-day hikes ?

The old Garmin eTrex used to have 24 hour battery life, plus you could take as many spare batteries as you needed, but most smartphones are lucky to be able to run in GPS mode for one day before the battery is empty.

I've been searching the web for ideas and these are some of the options I came up with:

* Spare battery (for phones which allow you to change the battery)
* External battery bank
* Solar charger
* Fuel cell charger (Hydrogen)
* Hand-turned winder for charging
* Motion charger (e.g. The Ampy)
* Cooking pot charger that uses a thermocouple

A spare battery or external battery bank is the most simple, of course, but what about for trips longer than just a few days ? A solar charger is obviously the most simple for unlimited recharges, but what if you don't have enough day-light hours in the same spot to charge up ?

What are people out there using and what works ?

Thanks,
Anthony.

http://www.binaryearth.net/HandyGPS
http://www.diamondspirit.net/adunk/

[n5750547]

I personally use a 10000mah battery bank or I pack two if I'm going for multiple days. I have a couple of different brands but my favorite is probably the Xiaomi ones that you can get on Kogan although they can only charge one device at a time.

Next purchase for me will probably be a solar charger...

Sent from my SM-N910G using Tapatalk

[n5750547]

I forgot to mention that with the solar chargers they usually come with tie outs so that you can strap them to the back of your pack while you walk (charging a battery bank or spare battery to use in your phone later)

Sent from my SM-N910G using Tapatalk

[Gadgetgeek]

For just a couple of days, the good power bricks outrun solar weight wise pretty easily. Remember that you need a pretty big panel to charge a smart phone, so much more than a little keychain unit. I would say that you just need to look at the walk, length, probable solar exposure(are you going to be mostly in the shade?) and then go from there. I'd give the fuel cell stuff a pass for now, it looks really cool, but its so new that I don't know if anyone has done major reliablity testing. (although you could maybe ask for one and see if you could help the mfg. out?)

[DanShell]

I use one of these.
viewtopic.php?f=21&t=19706&p=263343&hilit=xaomi#p263343

There are ALOT of power banks on the market but most are junk in my experience. This one is great value.

[Gadgetgeek]

read the wirecutter review on banks, might give you some ideas. I bought a powercastle and really like it, but my cheapy one does okay for one day.

[keithy]

I have the same powerbank that Danshell linked, and also have the 10400mAh version of that brand.

If going for a couple of days, the large battery bank might suffice. The number of recharges depends on your phone and the phone's battery size though. There are slightly lighter versions that use a flat lithium ion polymer battery compared to the Xiaomi battery pack which uses 18650 cylindrical battery cells.

If going on a longer walk (weeks/months) off the grid, then the solar option is viable, but does come at a weight penalty, and depending on the environment might not be as efficient in charging. I posted about some of my experiences with my various solar panels here: viewtopic.php?f=21&t=18151#p246900.

Using the solar panel in Nepal for 4 weeks worked nicely, combined with two 5000mAh battery packs I had at the time. I'm not sure I would use the larger 10400mAh or 16000mAh battery packs with my current solar panels though, as the charge times to fill them is quite long. The solar panels still work as top ups for the larger battery packs though. But as others have said, it depends on the environment you are walking in.

I took a solar panel walking in Borneo, and being under heavy rainforest canopy with scattered light on trails it was difficult to get good charging while walking. At at camp sites it worked when it was clear, but in the tropics it can be quite overcast. So in that situation, doing it again, I would opt for carrying a larger battery pack and just ration battery use.

[madmacca]

In order of decreasing weight efficiency:

* learn to conserve your phone battery (eg. killing unnecessary apps, using airplane mode, aggressive screen saver settings, longer delays between breadcrumb points, less frequent nav checks, etc)
* if you come across some car campers, ask if you can plug into a USB source, even if just for 10 minutes
* a spare phone battery (there are big losses in using a battery to charge a battery, so swapping is a better option, if available).
* an appropriately sized power bank.
* learning to charge your batteries strategically - it takes a lot more effort to charge the last 20% of a battery's capacity, so it is more efficient to maintain your phone at 50%, than it is to constantly "top it off".
* a solar panel. Solar panels have variable power output, and most phones and devices are pretty finicky as to the USB power quality they receive, so panels generally charge a battery to smooth out the power, then you use the battery to charge your device. You also need a reasonable sized panel to deliver anything more than a token charge. And all of this adds to the weight - solar panels are probably only worth their weight if you are out for a week or more, in summer, and are prepared to have a leisurely lunch or are on a southbound path.

Personally, I use a cheapie power bank with replaceable 18650 batteries:
* 18650's have been the standard for laptops for many years, and are the beneficiaries of a LOT of research
* replaceable batteries means I know the quality of the batteries I am using, rather than using whatever no-name brand is inside the sealed casing.
* replaceable batteries means I can carry enough and just enough battery for the length of my trip - 1 x 3200 mAh for a weekender, 2 x 3200 for a 3 day trip, 3 x 3200 for a 4 day trip, and 4 x 3200 for a 7 day plus trip, without having to lug a 15000 powerbank on a weekender.

[LandSailor]

I tend to try and standardize on AA batteries for everything. So I have a chargeable USB battery pack that contains AA batteries, plus my GPS, Delorme Inreach and headlamp all use AA batteries.
That way I can get good quality rechargeables and also have alot of flexibility to move batteries from one device to another as required.
The power bank Im using is this (probably need more than one for longer trips) :-

http://tekkeon.com/products-tekcharge1580.html

[Eljimberino]

Found this link : http://m.banggood.com/Original-Xiaomi-1 ... 53908.html

[jjoz58]

I have these for trips depends on the length which one I take, the 15600mAh http://www.ianker.com/product/A1252011 or 26800 mAh http://www.ianker.com/product/A1210012. Everything I carry charges off these, GPS, inReach, headlight and phone.