Keeping your batteries charged

7:12 p.m. on May 9, 2009 (EDT)
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I ran across this pack in, of all places, the American Express Rewards Program catalog:

At first glance, it appears to be a partial answer to the wilderness gadgeteer. But there are a few shortcomings. The pack is 30 liters (1850 cu in), a tad on the small size, though ok for a day pack. It weighs 3.5 pounds, which is quite heavy for a 30 liter pack. Charging times are roughly 4 to 8 hours for a digicam, iPod, or cell phone, and longer for the included lithium battery pack, and that is if the panels are directly illuminated by the sun (4 watt output). The time increases significantly for shade or increasing angle to the sun. Still, for some purposes, it could be useful.

11:08 p.m. on May 9, 2009 (EDT)
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To me, it would make more sense to buy one of the folding or roll-up panels and tie it onto your pack. This way, the panel could be removed and laid out in camp facing up for one thing and charging batteries while you are cooking, day hiking or just sitting around.

How much power are you going to be using on a day hike? I think carrying extra batteries would make more sense.

12:04 a.m. on May 10, 2009 (EDT)
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I use a Brunton 26w Solar folding panel. It folds up from 3' x 4' to about 8" x 11". Cost was $450 two years ago, now is around $600. Weighs about 1 .9 lb. I can charge my camera batteries, my laptop or just about any electrical appliance. If I had a car it would also recharge the dead battery if needed.

In direct sunlight it will power my laptop and keep it charge just as well as plugging it into a plug in the house. I love it when on bicycle tours and hikes.

4:54 a.m. on May 10, 2009 (EDT)
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Instead of walking along with some gadget that needs light to charge batteries, I have this tube and a few extra AA batteries in my pack. The tube weighs close to nothing. I have my gps, camera, headlamp and radio all using AA batteries. With the tube also my cellphone now does use AA's. So I do like Tom, take a few extra AA batteries with me.

8:48 p.m. on May 10, 2009 (EDT)
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I personally have the Brunton 26 watt folding panel. The weight with the needed adapters is a bit less than Gary quotes (I don't need the alligator clips for climbing trips). I have used it in Antarctica (6 weeks) and Africa plus shorter trips. However, it is a bit awkward to tie it over the pack to recharge batteries while hiking along (even using the provided tie-off grommets). As Gary notes, it is 21"x42", so the bottom hangs below my Dana expedition pack, and is way oversize for daypacks and my weekender packs. It is best to use it in camp. It does recharge my DSLRs' rechargeable lithium batteries (about 2 hours from full discharge) and other electronic gear (I do not have the recharge time for John's Iridium phone from Antarctica, but it was pretty short).

The pack I show above is really for a different purpose, namely day hikes, because of its small size and pocket configuration (the padded laptop pocket takes up a fair amount of space, plus adds a significant amount of weight). The other big limitation is, of course, the low power output (4 watts), meaning a long time for recharging many electronic widgets.

For many purposes, including expeditions, Tom and Otto are right - carrying a supply of batteries can be lighter. A small "brick" of AAs is lighter than the 24 watt panel and needed adapters. But some widgets do require rechargeable batteries and not take AAs or AAAs (yes, there are rechargeable AA and AAA NiMH batteries, but then you still require a way of recharging them). In Africa, we were able to get along fine with one spare set of AAs for Barb's Canon A620. But all our other cameras had proprietary lithium rechargeable batteries. I do have one of the emergency rechargers for my cell similar to the one Otto shows. But again, you are taking a device to provide a recharger.

Add in the limitation that became active Jan 1, 2008 - you cannot take spare lithium batteries (rechargeable or non-rechargeable) on airplanes in your checked luggage and no more than 2 spare lithium batteries in your carryon luggage. This does not include those lithium batteries in the device (in the camera, cell phone, MP3 player, laptop computer, flashlight, etc), just the spares, and does not include alkaline, NiMH, or NiCd batteries. Luckily, we returned from Africa Dec 26, just before the critical date. We had two spares for each camera, plus spare AA and AAA lithiums, plus spare Li rechargeables for our photostore hard drive, GPS receivers, and several other devices. With this rule, it becomes necessary to have a solar recharger anytime accessing the trailhead requires air travel.

11:22 p.m. on May 10, 2009 (EDT)
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I have never owned a solar panel of this type, how delicate are they?


12:31 p.m. on May 11, 2009 (EDT)
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The foldable and roll-up panels are pretty durable. They are somewhat less efficient than the rigid type that have a tempered glass cover. Voltaic (maker of the pack above, plus a number of other solar charger and battery products) claims their panels are quite durable, plus has made them replaceable on the pack and some other products as plug-in modules.

We had a couple of the Bruntons in Antarctica, mine and Sam's. So they were subjected to temperatures below -40 and being carried around in the packs. I didn't take any special precautions with mine in Africa. So far, it doesn't show any signs of wear and the charge times for my camera batteries seem to be in the same range as when I first got the panel.Some of the foldable and roll panels are intended for marine use and can be walked on when laid out on deck (not recommended as a regular practice, since scuffing the surface will reduce the efficiency in time, due to reducing the transparency of the overcoating).

I recently got an adapter for my camera batteries that seems more efficient and more durable than some previous ones. It is by Belkin. It takes clip-in adapters for most Li camera batteries, so it is more compact and lighter than the separate ones I had to take for each camera's batteries. Unlike Nikon's own chargers, it works off car and aircraft batteries (12 and 24V), as well as AC (100 to 250V, 50 to 60Hz). And it will do 2 batteries at a time, different from each other (e.g., a Nikon and a Canon, or Nikon EL3 and EL9).

8:21 p.m. on May 11, 2009 (EDT)
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The fact that so many cameras have proprietary batteries makes a charger almost a necessity. My old A95 uses AAs, but it's dying, so not sure what a replacement will use.

I have seen one small charger that has it's own battery then you recharge off that one, kind of like what Otto has. Seems a bit inefficient, but I could be wrong about that.

5:44 a.m. on May 12, 2009 (EDT)
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I've had the Powerfilm / Iowa Thinfilm Foldable Solar "AA" charger for a while now and it's fantastic. I went to "The Source" by Circuit City and bought 4 "AAA" to "AA" adapters so I could also charge the "AAA" batteries in my Petzl Tikka XP headlamp and my Black Diamond Orbit lantern. Works perfectly. 4 "AAA" batteries charge in quite a bit less than a full days bright sun. 4 "AA" batteries charge in one day, just. In cloudy weather, a full day for the "AAA", and two for the "AA". The charger has a couple of itty-bitty LED indicators for charge status. This is the one I have. I missed out on the USB and "AA" version by a couple months. Grrrr! The third pic is actually larger than life. And I don't think the version I have weighs more than a couple ounces.





6:40 a.m. on May 12, 2009 (EDT)
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For some reason, the website didn't like your other two pics. I tried to post them in your message - no luck. I also attempted to put them in a separate post and couldn't do it either. Sorry. Well we got one in there anyway, and you posted a link to the company so others can do what I did and check the device out there.

Thanks for posting your idea.

12:23 p.m. on May 12, 2009 (EDT)
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TCJ, The big problem I see with the solar charger you show is that it won't charge most (maybe any) batteries for DSLRs. The output voltage is much too low, and even for the AA and AAA the charge time is much too long.

Brunton has a newer version of the panel I have with higher output at the same size and weight, plus there are a couple of other companies with similar panels. It is a bit heavier, but for long expeditions the weight is worth it.

4:22 p.m. on May 12, 2009 (EDT)
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Thanx f klock! Hi Bill. I was actually thinking about the Brunton SolarRoll 4.5 for months before finally settling on the Powerfilm AA Charger. Mainly because none of my battery powered gear uses proprietary batteries, just AA's and AAA's. If I had gone with the SolarRoll I would have had to buy a separate module for charging normal batteries. Also, I'm sure the charge times will get shorter as the days get longer. The times I gave you were for early spring in Ottawa, Canada. It was still a really close thing choosing between the two though. The SolarRoll is TOTALLY waterproof. The Powerfilm... Not totally. Battery compartment isn't sealed. Oh well, I got it half price. $75.00 instead of $150.00. And for me, it's good enough for my needs.


4:31 p.m. on May 12, 2009 (EDT)
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FYI, I added the other two pictures to TJCeeJay's post.

The urls originally had some extra gobbledy-gook in them after each picture's url: "Picture one." and so on. I just stripped that out.

6:35 p.m. on May 12, 2009 (EDT)
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I figured it was something like that, I was just too impatient to look into it further. Thanks Alicia.

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