Extra batteries vs recharging via power bank

[chris smead]

Hey guys,

Im carrying tons of camera batteries on the trail these days.  2lbs worth to be exact for my GoPro and Sony A7.   When I add up all the mah ratings, it seems much lighter to carry a big 20,000mah power bank and just recharge my devices every night.   However I’m aware those ratings aren’t accurate and some energy is lost during the charging process.

Im sure it varies by case, but are there any general guidelines for determining which is a lighter setup?

[Jerry Adams]

recharge efficiency is pretty good, maybe 80%???, you have to try it, 20,000 mah is fairly inexpensive to try out

the power bank rating, 20,000 mah, is for the lithium battery which is 3.6 volts.  what about the GoPro and Sony?  Probably the same but if the mah is for a different voltage you have to factor that in

separate batteries is a bit more reliable – if the power bank fails then you’re done

 

[Jim C]

My hunch is that things would favor extra batteries in most cases. But I guessed you’d have to experiment and find how many charges you need and how many you get from the battery pack. I suppose there could be a point where the extra packaging of the spare batteries surpasses the losses from charging.

If you’re out for a longer period, and in a place like the Sierras where you get lots of sun and time above tree line, there might be a point where the scales tip towards a light solar panel and a small battery pack.

[Valerie E]

I see you’re in Cali, so +1 on the solar with/without a small “lipstick” battery.

My Suntactics 5 (7oz) plus 3oz battery worked fabulously on a 300 mile PCT section where we did two stints of on-trail-no-towns for 10 days and 9 days, respectively.  If you don’t have an iPhone you could probably get away with just the solar panel.  I need the lipstick battery because iPhones are too finicky for solar alone.

[Jerry Adams]

you have to be out many days before a solar panel will weigh less

a 20,000 mah battery will have a smaller percentage of the weight in the case and so forth than a number of small batteries – you just have to try it

[Thomas E]

First you have to convert to the correct voltage and then subtract 20% that will disappear due to inefficiencies.

For instance and 5000 mAh power bank is usually measured at 3,6 V while phones charge at 5 V. 5000 mAh at 3,6 V equals 18 Wh and if your phone is 3000 mAh at 5V that equals 15 Wh. 18 Wh * 0,8 = 14,4 Wh.

So, even if the powerbank is 5000 mAh and your phone is 3000 mAh it would not be able to do a full charge.

[Mark Fowler]

Depending on trip length I either carry a cut down Miller charger (21g with USB cable) and an appropriate number of Panasonic 18650 batteries (46g each) or a cut down Anker 15W solar panel (270g), the Miller charger and a single 18650 battery.  The break even point between the solar panel and batteries is six batteries in addition to the one I always have.

I usually only have to deploy the solar panel at lunchtime to keep everything (Petzl Tikka XP, Steripen Freedom, Samsung S4 phone) fully charged and am thinking of cutting the panel in half (currently 2 flaps) or getting a 7W panel which would reduce the balance point to 3 batteries.

I believe it is important to take at least a single battery and not rely on the solar panel alone.  I estimate from my usage that I can go about 5 to 6 seriously overcast days before starting to run out of juice with a single battery as backup.

[jscott]

Leave it all behind. Done.

We do possess memory, after all. Learning how to recall is time well spent.

[David Thomas]

Unplug!

Get off my lawn!

Back in my day . . .

[David Thomas]

• Now that I got that out of my system . . .

Check batteries for your device on eBay direct out of China. Some are so cheap ($1.37 each), that you can treat almost like disposables and include them in resupplies. Maybe mailing back / bouncing used ones, maybe just tossing them.

And check how many recharges you actually get out of a “10,000-mAh” battery. All the ones I’ve checked are only 30-50% of their claimed capacity

 

[jscott]

nm. I did spend about five years hauling around five pounds or more of photography equipment.

[chris smead]

Excellent points haha!  My first dozen or so backpacking trips I refused to bring a camera!  It never perfectly represents the experience so why bother?  Plus the idea of separating from all technology was super appealing.

That said, video making is my new hobby and I enjoy it a lot.  Combining this new hobby with my passion for backpacking makes it double fun, and it’s worth the extra weight.  I just need to go SUL in other places to try to help make up for it.  Anywho…

I’ve been carrying extra batteries and resupplying charged ones.  Seems to work well. But my new camera is a battery hog, so my spare battery bag is getting out of hand and making me revisit battery banks and solar.   Sounds like I need to do some experimenting.  Thanks for the info.  I’ll take all this into consideration.

[Roger Caffin]

Can’t help feeling that 1/2 dozen spare AA Lithiums might be extremely simple…
Cheers
(Um – if they fit!)

[Jerry Adams]

” All the ones I’ve checked are only 30-50% of their claimed capacity”

Remember the 10,000 mAh spec is of the 3.6 volt Lithium battery.  I’ve measured power banks a little.  The USB voltage is 5 volts.  When you factor that in, the 10,000 mAh spec, which becomes 7200 mAh of USB 5 volts, they’re within 10% of spec.  At least the Anker ones.  I looked at a couple smaller cheaper ones that were half of spec.

If you charge it from a solar panel there’s some more inefficiency, and the solar panel delivers full power only in full sun so there’s some more less than spec.

[David Thomas]

Jerry, yeah it was off-brand ones which were the furtherest off spec.

[BlackHatGuy]

Christopher,

I have a New Trent [email protected](37Wh) battery pack, charges smartphones at 5V/1A and tablets at 5V/2.1A. It’s not light – 8 oz.

But, I have no use for it. Pay for shipping and it’s yours if you want it. Let me know.

[Mike In Socal]

Here’s my general guideline: take spare batteries until the weight of spares is greater than a rechargeable battery pack.  Then consider the weight of one or more battery packs; if the weight of rechargeable battery packs exceeds a solar system, then go Solar.

For trips of 2-3 days, I take an extra battery pack to charge my Phone which I use for photography, reading and backup navigation.  Over 3 days, I start to think about a solar panel and solar-rechargeable battery pack.  I charge the pack with the panel during the day and then use the pack to recharge my device(s) at night.  I use a GoalZero Nomad 7 and a rechargeable AA battery pack when going Solar.  I use a Jackery Giant (10,000 mAh) when bringing just a battery pack.

[James holden]

Just be aware of safe lithium battery for loose bats handling prbactices …

or KABOOOM !!!

A Calgary man is recovering from severe burns after he says an e-cigarette battery exploded in his pocket Friday night.

Terrance Johnson said he was out for dinner with his wife when a loose e-cigarette battery in his pocket shorted. He said he believes it came in contact with some loose change.

Johnson now has third-degree burns to his leg and hand. <\blockquote>

http://globalnews.ca/news/3277002/calgary-man-has-warning-for-others-after-battery-explodes-in-his-pocket/

 

;)

 

[MJ H]

For my phone (Samsung), I bought cheap replacement batteries off Amazon.  They’ve been reasonably good for hiking trips of a few days.  Undoubtedly light compared to the alternatives and very cheap.  However, one got all puffy on me.  I’m thinking of switching to actual external batteries with casing and all.  In addition to not having to worry to much about them exploding, I can also use them when I fly.

[Roger Caffin]

Just be aware of safe lithium battery for loose bats handling practices … or KABOOOM !!!

Which is just so silly (on his part). Of course there is a risk with loose batteries, but that risk can be almost completely eliminated by a couple of turns of sticky tape around the terminals. Make it so the terminals are all insulated.

Note: This ALSO applies to carrying spare batteries in your pack! Tape the terminals.

Cheers

[James holden]

unless one has 18650 headlamp/flashlights … just use an anker power pack

honestly its not worth the hassle, never mind the risk of dealing with loose 18650 bats …. not to mention power packs have come done so much in price that its basically as cheap to buy a new power pack after a few years rather than loose bats

also power packs are much more suitable for an urban environment where youll really be using it …

in a way its fairly pointless to worry overly about the “most weight efficient” setup … as you Li-On bats will loose ~30% of the capacity in ~500 full charges or so … so if you want to be “as light as possible” then youll be buying a new powerpack every 1-2 years

if you do use loose bats … using PROTECTED bats is a good idea as they dont cost or weight much more … sure we know everyone here is perfect and no one makes mistakes when they are cold tired, in the dark and hungry … and of course the protection circuit aint perfect …

but then … KABOOOOM !!!

;)

[Miner]

I’ve never had any problems carrying extra lithium batteries on thru hikes; AA, AAA, proprietary camera/camcorder batteries, etc. I just put them in a Ziploc oriented in the same direction and put them in my small misc. CF stuff sack. No danger at all of shorting or getting wet.

[Author]

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