Backpacking - need help..

[dog812]

So i will be flying into a remote area with some buddies later this year. We are trying to figure out how to charge our GPS / Radios.
We all use the garmin rino. It uses a battery that is lithium ion 7.4v / 2400mah.
We do have a car cigarette charger attachment. Or a wall socket .. both output the same 9.5v @1.4amp

I am looking for a backpackable solar panel / external battery combo.. that is lightweight and wont break the bank..
If any of you have any ideas. or have used anything really good. i would appreciate the info.

[solarfrank]

you can go with brand names check on google or you can find some cheap stuff on ebay

[Mike90250]

solar panels and power adapters are not your answer, carry spare batteries. Less expensive, more compact, much more likely to work.

[Sunking]

Use spare batteries. Much lighter, smaller, and more reliable. To do it with solar means a large heavy panel, controller, and a very heavy lead acid or lithium 12 volt to use with your 12 volt charger.

So which is better?

1 A solar panel the size desktop, controller the size of a cigar box, car sized battery, and your 12 volt charger?

or

2. A few spare light weight batteries you carry in your pocket.

[dog812]

well i was looking at goal zero s sherpa 50.. small folding panel and light battery.. but $300 and it will only charge the garmin once per charge then ill need enough sun to charge it over and over..

Then i looked at the powermonkey extreme, cheaper, but same thing one charge for the garmin per full battery.. and its only a 3watt panel so take forever to recharge.

THe garmin batteries are $60 each.. and only useable for the garmin.. i was hoping for something i could use with other devices, cameras, gopros etc to recharge.

I was hoping a solar panel forum would have some info or idea that i didnt know.. but ill keep looking thanks.

[russ]

You can get 10,000 and 20,000 mah lithium batteries - not too light

[PNjunction]

The Rhino's I've seen can accept AA batteries which may be easier to recharge via solar.

In this case, use Eneloop AA batteries, (the standard from which us battery geeks base other manufactures from!) which are about 2000mah capacity. The li-ion batts are 2400mah, so you aren't sacrificing much, however GMRS radio usage would be best advised at low power and not high power for tediously long conversations. Of course FRS is low power already on those units (I think). You may actually do better in your application with the "XX" versions of Eneloop, which are close to 2500mah, but with slightly reduced cycle life. Even if you use them daily and not take advantage of their low self-discharge, their extremely low internal resistance, higher voltage under load, good construction etc make them a top consideration. You may find them as Panasonic / Eneloop these days.

Whatever you do, do NOT just get some junk off the rack at your local pharmacy. Note that Eneloops are often the target of counterfeiters - buy from a reputable dealer.

A backpackable solar charger that I use and recommend (the only one to do it *right*) is the Powerfilm AA solar charger. It charges 2 or 4 at a time. But it will take 6 hours to charge 4 cells in perfect conditions. Therefore, have a few charged spares with you if you need 24/7 operations. NOTE - do NOT consider the USB / AA combo, as that is a smaller panel. Stick to the one that ONLY charges up to 4 AA's. Take advantage of opportunity-charging when you can and top them up when convenient. Try to operate your AA's as a "pack", that is keep them together for your Rhino use only, and not be tempted to run some other devices and place them back into the pack later, which would now be totally unbalanced.

There are a lot of boutique camping panels out there, but if you are in SERIOUS need, then Powerfilm, albeit expensive at first, is no toy.

A larger, faster system can be built, but may be entirely less practical than just taking spare cells with you.

[russ]

For over a week or more maybe a charger is better - for a few days carrying a battery pack is far easier. That is unless you plan to be stationary where the panel may be aimed at the sun and adjusted regularly.

A panel on a backpack will get you next to nothing.

[PNjunction]

Oh yeah - a great charger for the AA's would be the Maha / Powerex MH-C9000, which accepts a 12v input as well as AC.

While it is a charger / analyzer, and looks complicated to use - guess what: it was designed to handle 2000mah AA batteries without the user having to do *anything* other than just stick them in and walk away. Once again, this is a charger that does it right. A walk-away charge from the Maha with Eneloops at 2000mah will take about 2 hours.

Russ - glad you mentioned that about the panels on the backpack - bad idea, although often touted by unknowledgeable sales sites. Like any panel, you'd want to be in good sunlight, preferable aimed it it, more or less stationary.

[russ]

I have 2 each 12,000 mAh Lion batteries for backpacking - recently took one on the Inca Trail to Machu Pichu in Peru - worked great for 4 days. It rained some and was generally not friendly to collecting anything from the sun. We were there for four days recharging Samsung 2 phones and one tablet.

Not terribly light (450 grams each) but it works for short periods.

[dog812]

I have the aa adapter.. 2 problems.
The frs radio goes from 5 watt to 2.
And with normal batteries , 4 aa last one day.
I will order some eneloops and try then, hopefully get better results.

[jimqpublic]

We have a Goal Zero Nomad 7. It worked fairly well for a 4 person, 3 week backpack trip where everybody wanted their "devices". It did not work well strapped to my backpack due to too many trees and a generally southerly hike direction (John Muir Trail). The best production was at lunch and rest breaks. If you aren't stopped much during mid day, I wouldn't suggest trying to recharge with solar. We directly charged iphones, an ipod, and a Kindle with the usb output.

For myself alone I just use less power (flashlight and camera only) and don't bring the charger.