UNSUPPORTED: how to recharge phone, SPOT, headlamp?

It is extremely simple.

Real cameras (ie not smart phones) do not need a lot of power. They are switched off 99% of the time. We carry a spare fully-charged camera battery for 2-month long trips, and take a lot of photos.

My headlight uses one AA lithium battery. I can buy those fairly easily when the single battery dies after maybe 4 weeks, or I can carry one spare. Li AA are light. I usually run my headlight on ‘glow’ rather than ‘searchlight’. Moonlight is often enough.

My watch battery lasts a year. I put a new coin-cell in before a really long trip.

I do not carry a smartphone, a sat-link phone or a GPS or anything else, so I don’t need extra batteries. And I don’t carry the cost or the weight of all those frills.

And that’s it folks.

Cheers

I recently backpacked an 11 night/12 day stretch and used a Lixada solar panel to charge a jackery mini powerbank (3,350 mah) only one day, about halfway though the hike. In camp I charged an iphone SE first gen (1,624 mah) and steripen ultralight (1,000 mah) from the powerbank. My nitecore NU20 headlamp didn’t need recharge.

The sizing of panel and powerbank depends on your mAh needs, sunlight, etc. Also, this panel may not work for all. Some recommend superglue to the usb connector box to make it live longer ; ).

Some also can get by with just a larger powerbank (without solar panel) if it meets your mAh power needs.

https://tinyurl.com/56swuzmv

Here’s my thought process on batteries:

My phone lasts a good 3+ days using it occasionally as a a GPS, taking a couple dozen photos and listening to a little music or a podcast for a bit as I fall asleep. I don’t use a headlamp much because I’m not hiking at night. I send off a couple InReach “doing ok” messages a day. I’m not tracking things all day long on my GPS/InReach, listening to music 12 hours a day, and shooting videos as I go down the trail.

My point is that it sounds like I would need to recharge my phone maybe four times during a two week trip. I’d have to look it up but I think I’d be able to do that and top off a couple other devices a little with a 20,000mah battery and I think that would weigh a little over a pound ~12 ounces. That doesn’t seem like the straw that would break the camel’s back if I was already willing to carry two weeks of food.

Yes a solar panel with a small battery could work if one was in an area that is fairly sunny. It might make more sense than carrying the weight of batteries but it requires you not be under trees all the time. If you are going to try out a solar solution, you should experiment with it in the field before relying on it. I made some incorrect assumptions about solar on a long trip once and regretted my decision (I was trying to charge direct without a battery). It seemed like it worked in my backyard… A small lipstick battery would have been a really smart 3 ounces to carry on that trip.

Rex’s comparison of battery banks: https://backpackinglight.com/anker-nitecore-portable-battery-charger-tests-batterybench/

Ryan shares his thought process on recharging devices: https://backpackinglight.com/ultralight-ultra-performance-backcountry-electronics-for-2018/

If you plan to use electronics exclusively take Matthew’s advice and carry a 20K power bank but break it up into 2 10K banks. Redundancy. About the same weight or less. Watch power usage and be prepared to take less photos and turn off your phone when not needed.

My experience across several models of iPhone show they consume 3-5% battery per day on airplane mode. The camera works in airplane mode. I only turn the radios on when I really need them and then it’s back to airplane mode. I find it rather easy to squeeze 4-5 days out of a full charge on an iPhone 13 mini.  I own two 5000 mah and one 12000 mah battery banks and take one or more based on trip length.

Of course, you can eliminate that 3-5% loss by turning the device completely off.  That would only work if you left it off most of the day as I suspect booting up the device multiple times a day might consume that 3-5% you are trying to save…or more.  Here is an article (from 2016) that may confirm that.

Regularly get a week out of an android device following JCH’s basic policy plus a battery saver app that lets me control what gets activated at startup. Pretty much use it only for photos but does give redundancy for gps and allows custom text messaging with the InReach app  should something weird occur requiring ‘custom’ messaging. Get weeks out of an InReach mini charge The InReach gets booted up 3 times per day to verify I’m on the pre-recorded route and OK for the family back home.  For light I use a couple of photon microlights (backup – redundancy re Larry W) plus 2 extra 2032 batteries weigh a few grams. I really like microlights but seem to be in the minority around here on that. Hey it’s backpackinglightly with  light! They also last like at least a month of ‘normal’ use. If I was going to take tons of  photos over a couple of weeks I’d might follow Roger’s routine with a dedicated camera instead of the phone (Roger’s so reliably/admirably Old School. That’s maybe why he’s made it to old?)  I’d probably go completely ‘Roger’ if the phone didn’t take such great photos and require an expensive camera to duplicate. For a couple of weeks maybe take one of those new 10 MaH bricks that are getting pretty small and light but I’d still focus first on not needing a charge. Always take a printed map for backup just in case plus if you learn thoroughly how to use it it’s the lightest weight and reliable and you can not duplicate the ‘big picture’ provided by a map with an electronic device that doesn’t have a very large screen. Also Won’t break! Another chance to cheat Murphy! Guess I’m old school too. And Oh yeah; always carry at least a button compass. Murphy again. I swear the guy is my Siamese twin.

Counter-culture, old-school Roger, just leave it home… geez… all the lady asked for was what size power bank and/or solar panel…

About now I expect

Andrea is probably sorry she asked… :)))

Agree with DWR, those type replies are not good for people asking for help.

“In the simplest possible terms, just be helpful, positive, and inclusive.” ~ BPL Posting Guidelines

https://support.backpackinglight.com/article/48-are-forums-moderated-what-are-your-guidelines

https://backpackinglight.com/battery-bench-test-explainer/

You will usually regret taking less energy than you really need. So don’t cut it too close. The hard part is not taking too much. Most of the existing advice boils down to “see what works for you.”

In theory you could figure out what you need:

– Take a 3-day backpacking trip with the battery-powered devices you plan to carry. Call it a shakedown trip.
– Use the devices as you would on the longer trip.
– When you get home, measure how much energy (Watt-hours not mAh!) each device takes to recharge.
– Do a bunch of calculations that make my head hurt trying to explain, to figure out how much recharge energy you need on your longer trip.
– Add 10% to 20% more for safety.
– Take enough battery pack(s). Except all makers implicitly exaggerate delivered energy capacity by a significant amount, sigh. More measurements, more calculations.

Plus:
– Follow effective practices for conserving energy while backpacking, especially not recharging smartphones overnight!
– Have a plan for using less energy when you start running low. Like telling people at home you are reducing or stopping satellite messaging or tracking.

Not easy.

More details:
https://backpackinglight.com/simple-gear-tests-usb/
https://backpackinglight.com/episode-56-portable-battery-chargers-for-backpacking/

— Rex

Interesting side note:  There is a show on Discovery called The Last Alaskans about the last handful of families allowed to live in the Alaskan Arctic Wilderness.  I find it fascinating as these people are living and working (hunting, fishing and trapping) outdoors, all day, in 40 below hip deep snow.  I love seeing their methods.

To the point – While following one of these trappers in some pretty nasty weather he said “Never rely on anything with a battery…it WILL let you down”.  I believe him.

Beautiful suggestions, everyone, and thank you! I’m not bothered by the old-school minimalist replies. They add more perspective (and a reminder that a paper map ain’t a bad idea). Because my trip would set an FKT, I’d need gps tracking for sure. I may not take 500 pics like I did my first time on the trail, perhaps more like 100. I charged my iPhone SE about every 4 days back then, but it was a new phone (and therefore new battery!).

I may end up with 2x 10,000 banks, or a tiny lipstick bank + UL solar. Of course the field testing is fun, too. Seems like the latter option is more reliable, in that I can regenerate power “myself” (in the field) rather than having a fixed reserve that could deplete.

Bare minimum is I’d need to charge phone & gps device. Bonus would be rechargeable headlamp, if I don’t go with a lithium ultralight option and 2 extra batteries. I can’t leave ANYTHING in the trash as I go, so all the weight is meaningful. (Of course you get it, because which group am I in, after all!?) *grin*

FWIW, I’ll still reach out directly to folks like Olga King and Legend to see what they are really doing on those unsupported FKTs… other name-dropping suggestions?

Garmire (Legend) may have had his gear list posted on his website. Heather (Anish) Anderson would be another gear list to check out. Good luck on your FKT attempt.

Andrea,

You can figure out how much battery capacity is left in your iPhone SE:

Settings > Battery > Battery Health and Charging

My 3.5-year-old iPhone shows 84%, and it doesn’t decline that fast, depending on your usage patterns.

A few other thoughts:

– Directly solar-charging devices like iPhones and headlamps usually doesn’t work well, especially with moving clouds and variable trail shade. That’s where you’ll want the lipstick battery to soak up the sun’s energy, since for an FKT you probably won’t be sitting around in broad daylight for a few hours each day. Except solar to lipstick to device wastes more energy.

– If you don’t need much power, one or more battery packs probably won’t weigh more than a big-enough solar panel plus lipstick battery. Small solar panels (roughly hand-sized) are almost worthless. Testing before your FKT highly recommended.

– The Nitecore NB series “carbon fiber” battery packs have the highest delivered-energy-to-weight ratio in my testing, by a fair amount. But they are not drop-proof, so treat them with some care. If you feel clumsy, Anker battery packs are very tough, but weigh more. Tradeoffs.

Good luck!

— Rex

Just a thought: Your direction might matter. Going mostly north for your whole trip? You can hang a panel off the back of the pack pretty easily. If you are doing a large loop it might be more difficult to keep the sun on the panel.

For 14 days I would be comfortable with two 10,000mAh power banks. I recently did a 9 day trip with one 10,000 and an iPhone 11. Almost daily off-trail navigation and a few dozen photos and I had charge to spare. That did include powering off and keeping both phone and battery warm at night.

I have these:

https://www.amazon.com/Anker-Ultra-Compact-High-Speed-VoltageBoost-Technology/dp/B07QXV6N1B?th=1

it all depends on how much you use which devices

I have a 10,000 like Craig’s – 7.5 ounces

It wasn’t quite supplying what I needed on some trips, so I got a similar 13,000 – 9 ounces

I’ll use one or the other depending on the trip

Rex’s recent BatteryBench work, the Nitecore vs. Anker tests, and Drew’s Nitecore NB10000 review have all caused me to rethink my electronics strategies on long trips.

There’s no situation where I can work out the math of carrying a solar panel in lieu of an NB10000 (or multiple ones) that provides any meaningful weight savings until we’re at the 3-week mark or so and have reliable sun, and I want to mess with it (I’m not sure I’d want to mess with it on an FKT).

The phone is the biggie, it’s a huge power drain if it stays on, or if it gets cold, or you’re shooting a bunch of video. This past year, I’ve leaned more heavily towards using a GoPro or other action cam if I’m doing video (vlog style) footage, and carrying spare batteries for that, and keeping the phone off.

The phone is now used for incidental navigation when map and compass reach their limits or becomes “too slow” (which is rare), or inReach custom messaging check-ins (evenings).

I use the NB10000 every few days to top off the phone, GPS watch, and headlamp, and can easily stretch one brick to a week of travel. As has been mentioned multiple times before, take two bricks for redundancy, and better energy density (from Rex’s work, 2xNB10000 provides higher energy density than 1xNB20000).

If you get one battery and then decide it’s too big or little and buy a second battery, keep the first battery to charge everything up when you’re in your car before you take off

I noticed the 10,000 Anker is 7.5 ounces, 20,000 Anker is 16.4 ounces, slightly more than twice.  How weird, normally you would expect the bigger one to weigh a little less per mAh.  Maybe the 10,000 has a newer, more dense battery.  Yeah, like Ryan said, two 10,000s are more reliable because one can fail.

That Nitecore looks pretty good – slightly lighter weight than Anker

There’s another unit where you can swap out the actual batteries so take as many as you need

Like Roger, I take very little that needs power — a camera and a headlamp. But that isn’t helpful for this conversation.

I do have a lot of experience using solar systems for my campers over the past 20 years and remote battery power for three telescopes and mounts. Over the years I have done extensive real-world testing on all of them. Also, I have a small GoalZero solar panel that does put out its rated capacity Under Ideal Conditions, but is nearly useless for charging while hiking. If one is spending a lot of time in campsite during daylight, it is practical but heavy.

I suggest you go back and carefully read all of Rex’s posts, and the link Ryan provided for a report Rex did.

Of great importance is this comment Rex made:

When you get home, measure how much energy (Watt-hours not mAh!) each device takes to recharge.

AmpHours or mAh means nothing unless we know the voltage used to calculate the mAh specification and many battery capacities are calculated at 3.7 volts. Unfortunately an iPhone and many USB devices are charged at 5 volts, which will reduce the stated mAh capacity. As Rex stated, use Watt-hours as it is not voltage dependent. One can only do a true Apples-to-Apples comparison when using wH.

For example the 10,000 mAh battery Craig linked to is 10,000 mAh at 3.7 volts, which is 37 wH. 37 wH at 5 volts is 7,400 mAh.

I have been using TalentCell batteries for several years and I do not care about weight since I don’t take them backpacking. But here is some info . . .

Talentcell Rechargeable 12V/6,000mAh; 5V/12,000mAh

(no spec given for 3.7V, but it is 19,459 mAh). This is a 72 wH battery. It can also provide 12 volt power.

Talentcell Rechargeable 12V/8,300mAh; 9V/11,000mAh; 5V/20000mAh

(no spec given for 3.7V, but it is 27,027 mAh). This is a 100 Wh battery. It can also provide 9V and 12V power.

The weight specification is not provided. I have four of each and can weigh them if you like.

Edit: You need something to measure consumption. These kinds of meters are inexpensive and valuable!

Hi Nick
That USB tester is something new to me. I must investigate!
I have in the past carried a solar cell on my pack:

But I do not know how much charge it was able to deliver: I was not carrying a voltmeter. For reference: the panel was carried on TOP of my pack, where it was most exposed to the sun. Having it hang vertically seems doomed to uselessness, imho.

Cheers

EDIT: Indeed! I have searched ebay just now and they have wondrous numbers of little USB meters which would be ideal for monitoring a solar cell. They were not available back then . . .

Cheers

Yes, the USB meters are great little units. The one I bought came with USB to alligator clips, which are handy.

Years ago my wife bought me a GoalZero Nomad 7 solar panel and a Guide 10 battery back (NiMH). It works at specifications, under favorable conditions — such as 7,000 feet elevation in the Sierra Nevada in the middle of summer while sitting in a campground — where I did some testing on a camping trip with our tent trailer and wrote about here on my website.

The challenge when backpacking is keeping the panel oriented in the best position to maximize the sun and even more challenging is to stay out of the shade. Seems only desert rats like to hike out in the sun. Solar panels for backpacking isn’t practical for most people, and for them it would be better to bring spare batteries. Unfortunately more and more devices do not come with replaceable batteries. They need to be charged while in the device, which I see as inconvenient and not the most efficient way to operate in the field over a period of time. So I leave all electronics at home except a headlamp and sometimes a camera. I leave my cell phone in my truck at the trailhead as there is no cell service where I hike, by design ;-)

Let’s face it, today more and more people want to take fancy electronic devices. Nothing wrong with that — us dinosaurs excluded.

So for these folks a separate battery bank is the viable solution. What I don’t like about the industry is the use of mAh as a capacity indicator. Especially calculating mAh at 3.7 volts. However, if the consumer is educated they can wade through the stuff and figure out what they need. At least if all their devices are charged via USB, then it isn’t too difficult. Should a device require a wall-wart at a different voltage, that becomes problematic. This is where the TalentCells are helpful. I can run my smallest telescope mount (12 volt) and also use the battery to charge a USB device. I have found that many small devices with wall-warts and barrel connectors at the device (5.5mm X 2.1mm or 2.5mm) are supplying 12V DC.

My strategy was to bypass all the calculations.

I just bought a 10,000mAh battery bank, ran my phone down, them timed how long to recharge the phone, and then ran my phone down again, and charged again until my battery bank was finished. Then I knew how many times the battery bank would recharge the phone. Could do that with all gizmos anticipated for the trip. After that, if 10,000 is not enough, buy another. or just buy two anyway and only take one if the testing shows you only need one. They’re also handy to have around the house when the power goes out for several  hours or a day to charge your phone.