Solar Charger

[davehuth]

My wife and I will be on a 12 day backback this spring. We'd like to make sure our camera (and GPS) are powered for the duration. Do backpackers bring extra batteries or use solar chargers? I was looking at solar chargers, they seem reasonable, yet it appears easy to make a wrong choice, and its not clear that they are advantageous in terms of weight and/or space.

Any advice?

[DOSS]

I don't have a solar charger, my normal method is to bring extra batteries and limit use.. I would like to get a charger as some point but I would have to change both camera and GPS so I could have interchangeable batteries and use the solar charger to charge a spare set while I use the others and swap around as needed :)

[Sombeech]

I've been looking at chargers like these too, pretty cheap:

http://www.amazon.com/gp/product/B00...SIN=B0036ORMS0

and

http://www.amazon.com/gp/product/B00...SIN=B001RMBHMK

[Jammer]

I used one like this on my hike across southern Utah:

http://tinyurl.com/35bwvdc

I loved it. Rugged and not much weight. One trick-- also get a universal adapter w/battery too. This allows you to just charge the generic battery each time, then charge your various items in the tent at night or whenever. This way you don't have to take the car adapter for each electronic device as well.

Are you doing the the full 12 days w/o a re-supply? If you are doing 1 or 2 re-supplies, it might actually be less of a hassle to just do extra batteries (depending on the number of devices and the rate at which they need charged.)

- Jamal

[cachehiker]

I used an inexpensive 4-cell solar AA charger with NiMH batteries on a week long, semi-supported bicycle tour. YMMV but in hindsight I would've carried a dozen alkalines instead. I've also carried it on a couple of road trips. I still have it and for longer trips abroad, I'd consider carrying it as a backup.

The GPS drained three NiMH cells on a daily basis. The camera drained four NiMH cells every other day. Unless I had bright sunlight, the charger really wouldn't keep up. It wasn't a fancy rapid charger hooked up to a 9 Watt panel so it took 5 hours to deliver a full charge to a set of batteries. I therefore had to have it strapped to the top of the rack all day, every day and cross my fingers that I'd have cells ready for the camera when it needed them.

I know it isn't the environmentally sensitive thing to do but alkalines would've gotten me an extra day per set, taken up less space than a charger plus 8 extra cells, and would not have required bright sunlight to keep up. Eight days would've equalled 12 cells (9 spares) for the old GPS plus 12 cells (8 spares) for the old camera. Picking up an extra 8-pack of batteries on a 12-day backpack won't be possible unless you've got a resupply point set up somewhere along the way though.

I've since updated my camera and GPS so the old charger would keep up in less than bright sunlight. Still, carrying alkalines would only mean 6 cells (4 spares) for each, less space than a charger, and no dependence on sunlight.

I still plan to use rechargeable NiMH cells on day trips and overnight trips but the tweener trips of 3-8 days will continue to have me switching to alkalines.

[cachehiker]

After looking at the rated (reviewed) alkaline (130 pics) vs. NiMH (2-3x as many) battery life for the Canon SX130, I'm beginning to wonder if my NiMH cells are getting too old and running into self-discharge problems. I cut my teeth using film in a Minolta Maxxum and don't usually take a lot of shots only to spend hours sorting though them later. 130 shots is typically about 4-5 days or more of composing and framing. I suppose it's very possible my 5+ year old NiMH's are now losing 50% of their capacity in a few days. They used to hang on to 80% for a week.

[Deadeye008]

This is the solar charger that I have.

http://www.disasterstuff.com/store/p...ger-88p284.htm

It folds down really compact and weighs practically nothing. There are many adapters that you can buy for them. Mine came with a 12v female cigarette lighter adapter so you can use anything that will plug into a cigarette lighter. I use my cell phone for a GPS but it drains the battery quick. This charger, in full sun, will charge my cell phone battery in around 2 hours. I've even used this strapped to my backpack while I was hiking and it worked great. For the price you can't beat these.

[cachehiker]

NiMH cells are getting too old and running into self-discharge problems.

I eventually verified this. The cells are almost 10 years old with over 200 charge cycles each. The total capacity has dropped from 1700mAh to 1300mAh. They also lose almost half their mAh capacity in 15 days. I finally broke down and picked up some NOS Accupowers optimistically rated at 2900mAh each. After a solid forming charge, they currently test out at 2500mAh each and hold 75% of that for about 30 days.

In bright sunlight, the 12V 5W solar panel mentioned above would take 4 hours to charge a set of four with an 85% efficient charging circuit. From the above testing, it appears my solar charger must be something on the order of 2.5W => 8 hours to charge a set of four 2500mAh cells.

[PLC92084]

Deadeye008 -- Did you have any problems with getting your devices to charge? I've noticed such things as cell phones, ipods and the like seem to require drivers in order to charge with the solar chargers I've tried. The "low-cost" solar chargers I've used don't work with my devices; even leaving them plugged in for 24 hours!

I've not done enough research to determine the difference between a solar charger with USB connection and my AC wall-adapter with the same USB connector... When charging the devices with a PC, I have to load drivers before the device will charge.

[Dr. Nebz]

This is the solar charger I have:

http://www.solio.com/charger/

It is awesome! You can load it up fully charged before you leave for your trip, and when you have used the charge, sit it in the sun, or tie it to your pack while you are adventuring so it is getting sun, and it will charge for you. About 8 hours in the sun for a 5 blip full charge. I have done 2 Ipods, USB rechargeable batteries and a digital camera on one charge. They have a ton of adapters, so check your devices and see if this accommodates them. I have had mine for going on 5 seasons, and it still works like a champ. Hope this helps.

[Deadeye008]

Deadeye008 -- Did you have any problems with getting your devices to charge? I've noticed such things as cell phones, ipods and the like seem to require drivers in order to charge with the solar chargers I've tried. The "low-cost" solar chargers I've used don't work with my devices; even leaving them plugged in for 24 hours!

I've not done enough research to determine the difference between a solar charger with USB connection and my AC wall-adapter with the same USB connector... When charging the devices with a PC, I have to load drivers before the device will charge.

I've never had any problems charging devices with my solar charger. I have charged them by pluggin the solar charger directly into the device and also using a universal battery charger like this one to charge extra batteries while I use the device.