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Latest, Lightest Solar Charges?
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Simon Roth

Locale: Northwest
JOOS Orange on 12/18/2012 22:01:13 MST Print View

I have the joos orange as well and love it's ability to charge and take a charge and all that. It's just a huge PITA to pay 150$ for something that ends up being one of the heavies things in your pack. Oh well, I've learned my lesson and will be getting an extra capacity battery case for my phone that will boost my battery life.

Now all I've gotta do is get rid of the JOOS.


Matthew Hoskin

Locale: Kanangra-Boyd NP
Re: Re: Max on 12/19/2012 00:34:01 MST Print View

You're absolutely right Bob!
A charge controller is an often overlooked piece of the puzzle that may do not realize is a SUPER important part of the equation.
I guess for those who are not in the know, the following is "really" the essentials to charge devices in the field.
1. Solar panel ( either foldable or rollable)
2. Charge controller ( to regulate the power from the panel as it fluctuates)
3. Powerbank ( storage for the power produced from the solar panel )

If you do your homework and take the time to learn about solar, you will realize that still now there are now real lightweight options. Sure you can get some little 5 watt panel with a 5V USB outut, but.... will take atleast 8-10hrs to charge a few AA batteries, in full sunshine. OK if you are staying put everyday, but for on the move, you really need a panel ( or set up ) that will charge a smartphone, or tablet or AA /AAA's. Let's say you are out for a weekend. Your best bet is just to take a batterypack/powerbank/etc,etc. Usually they are a Lithium Ion battery pack. For the above mentioned devices I wuld say a 40 Watt hour ( Whr) pack would suffice. Let's say you are wanting to watch a movie a night, well that would serve your needs. But.... if you go out for a week or more, then you will obviously need to think of charging that powerbank ( big battery pack ). The problem is that for us UL'ers, the only options are the rollable or foldable panels from either Powerfilm or Global Solar. - That is, they are the thin film technology products, but the trade off from light weight and packability is tht they are inefficient. I learnt the hard way, I lived in the High Arctic for 10 years, and at times spent weeks out camping/hunting etc, and needed to power/charge a GPS/ Iridium sat phone/ AA's etc, I bought a Iowa Thin Film ( powerfilm ) panel and unless I had fll sunshine ( yes only in summer or late spring north of 60!!!), it wouldn't even recharge the sat phone.
I then looked into the options, and learned about charge controllers, watt hrs, amp hrs, etc etc. In my opinion I would recommend you go for slight overkill and get a system that is more powerful than what your calculations work out to. Just think of how many days of your trip that you have full sunshine and are in a campsite etc that affords full sunshine???!!!. If you want to say keep an ipad/tablet, and a smartphone, and lets say 2x AA's alive for a week - then go for the highest wattage monocrystalline panel you can afford ( they come as foldable panels). At least a 40 watt panel is the realistic size. then get a 2 amp charge controller, and look for a lithium battery pack ( there re a million on Ebay and alibaba) at around 50+ watt/hrs). For trip and usage of around let's say 4-5 days - you can most likely get away with just the battery pack.Powerenz ( US cottage company ) have many really good options ( albeit expensive). If you research, you will realize that most companies will buy their panels and battery packs/powerbanks ( apple is one of them!!!), from China, and Brand Name them with their own and charge you a huge markup, or you can go online and do your homework= learn about exactly what you need and buy a nice setup from Alibaba/Ebay for a reasonable price.
Solar is awesome. Unfortunetely brands like Goal Zero market their stuff as the best, but their gear is overpriced to the max, heavy and VERY impractical for all hikers bar car campers ( IMHO!).
Research, research, research. Learn how Photovoltaics work etc, then you will realize that you can get great free energy for an initial low cost, or you can be a sucker and believe some of the manufacturers that will sell you underpowered products and you will just walk away mad and disgruntled and think Solar is still a joke - which it isn't!.

Tony Fleming
(TonyFleming) - MLife

Locale: Midwest
Solar Options on 03/24/2013 20:58:37 MDT Print View

Matt Hoskins,

If you're out there, would you mind sharing more specifically what you bought as a solar solution?

Thank you,

Tony Fleming

Vince Contreras
(pillowthread) - F

Locale: like, in my head???
+1 to fold-ups and battery bank... on 03/25/2013 11:04:40 MDT Print View

^^^^this. I use an old brunton panel and one of the bajillion batteries available on amazon. If you have more than one device to keep powered, go with a 20 watt panel and a 10,000mah battery; if not, than less.

Joseph Brody
Blackburn Flea Solar Charger on 08/21/2013 22:04:05 MDT Print View

Anyone try the Blackburn Flea Solar Charger?

It works to charge a LED bike light.

 photo photo14_zps1f60f59c.jpg

Edited by Killroy1999 on 08/21/2013 22:08:07 MDT.

Lowell Mills
(FarmHand357) - F
iPhone 5 off when charging to obviate need for external battery? on 08/22/2013 13:29:55 MDT Print View

I have a folding 12W solar array and use a 12V automotive-plug-to-USB adapter (the 5V, 2.1A kind). I noted that it would charge my iPhone 5 directly, unless a cloud passed by, which would kick it into the mode of telling me that this was not the correct kind of charger. Unplugging and replugging it got it charging again until the next cloud.

Just wondering if once it starts charging, if I then shut it down, will it continue to charge but without the discriminatory circuitry that keeps stopping the charging when the direct sun is interrupted?

The reason I ask is this same panel seems to charge my MacBook Pro when it's asleep, even though the wattage is well below the 65W provided by its power supply...

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: iPhone 5 off when charging to obviate need for external battery? on 08/22/2013 14:24:42 MDT Print View

>"which would kick it into the mode of telling me that this was not the correct kind of charger."

I get that with various marginal chargers, loose connections, and having too many apps running for some chargers to support.

Could there be an app that would clear that fault and let the phone try again to be charged? The only solution I've found is to unplug and replug the cord?

>"Just wondering if once it starts charging, if I then shut it down, will it continue to charge but without the discriminatory circuitry that keeps stopping the charging when the direct sun is interrupted?"

For some of my marginal chargers, I need to do that. If the iThing is off, it turns on when I connect the charging cord and often, quickly goes into "charging not supported with this accessory". I've had better luck having the iThing on, shutting down all apps, connecting the cord, and then quickly powering off the unit (just the quick, one-button push. Not the long-hold then thumb-slide shut down). Sometimes it still stops the charging before reaching 100%, but the above procedure gets me much further than leaving the unit on. So the discriminatory circuit still seems engaged, but by reducing the power draw of the unit, charging is supported for longer periods.

Lowell Mills
(FarmHand357) - F
iPhone 5 off when charging to obviate need for external battery? on 08/23/2013 11:01:19 MDT Print View

Interesting; thanks, David. I tested my phone last night by plugging it into a USB port, then doing the complete shutdown (holding down the top button until I can use the red slidey thing at the top of the screen to shutdown).

Of course, now I can't tell how quickly it's charging, but it would see that there's essentially no current draw in this mode and that it might consistently charge, even on a partly cloudy day.

I will try to set up this experiment; I would think this would be great if it eliminates the need for a buffering battery intermediary...

Joseph Brody
Going Solar Light on 08/23/2013 19:31:11 MDT Print View

I actually work at a Solar Company that makes roof top module, but no device chargers. I don't have solar module design experience, so I asked someone savvy today. He had a printer letter size module that is thin. Our product is a flexible laminate where silicon based solar is rigid and brittle, so our stuff can be a lot lighter and durable. The design is a nominal 5 volts and he said that with the performance of the cells, its possible to charge without any extra electronics.

Yet, its still to big and heavy compared to a little 35g battery that I have. I'n not sure what the power is, but I think it could be downsized. I would not want anything bigger than a postcard.

I think all I need is the battery for 6 day trips. I'm going backpacking, I don't need to be playing with electronics for a 5 day trip. Maybe for a 10 day trip next year.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Going Solar Light on 08/23/2013 19:44:54 MDT Print View

"Our product is a flexible laminate where silicon based solar is rigid and brittle, so our stuff can be a lot lighter and durable."

If your product is not silicon-based, then what is it?

The current types of solar chargers use either single-crystalline silicon (for high efficiency) or else amorphous silicon (for flexibility).


Joseph Brody
CIGS on 08/23/2013 21:30:56 MDT Print View

Bob, I'm talking about CIGS.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: CIGS on 08/23/2013 22:03:18 MDT Print View

So, what commercially viable solar charger products are there using this?


Joseph Brody
Global Solar on 08/24/2013 08:21:05 MDT Print View

This one is down 112 g, but still fairly big.

Edited by Killroy1999 on 08/24/2013 08:24:03 MDT.

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Global Solar on 08/24/2013 08:46:54 MDT Print View

2 watts maximum output (400mA) is rather anemic.

For most backpackers the technology isn't there yet. Over the past 10 years I have spent nearly 1,000 days off the grid utilizing solar in my tent trailers, so I have a little bit of experience.

You might find this interesting. Solar for backpacking?

For thoughts on charging strategies and system sizing read this. RV Solar Systems

Keep in mind, I am not an advocate for things electronic when backpacking. But if I were, spare batteries or a battery pack would be my solution, given the current state of technology.

Edited by ngatel on 08/24/2013 08:47:46 MDT.

Zorg Zumo
(BurnNotice) - F
Re: Latest, Lightest Solar Charges? on 08/24/2013 09:19:11 MDT Print View

I used a Brunton Ember on my last trip. Charged my phone very fast. Weighs 142gm. Major downside is that it lacks any attachment points. It would be nice to have it on my pack charging while I'm hiking. Otherwise very simple use.

Joseph Brody
Re: Re: Global Solar on 08/24/2013 17:21:09 MDT Print View

"2 watts maximum output (400mA) is rather anemic. "

A USB only charges at 500mA. Of course if you are hiking, the panel is not going to be directly facing the sun(as mentioned in your link), but if you are carrying solar weight, it better be put to use on your pack all day when you don't have a full charge.

In the link the solar charger was used was 360g. I never play with that many electronics to want to carry 360g of solar charger. For that weight, I could carry enough battery's to charge 10 iPhones.

Joseph Brody
Re: Re: Latest, Lightest Solar Charges? on 08/24/2013 17:23:23 MDT Print View

The Brunton Ember charged your phone fast because it is a big battery. The solar is only good for 100mA max. I would call that anemic.

Edited by Killroy1999 on 08/24/2013 22:08:44 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Latest, Lightest Solar Charges? on 08/24/2013 17:40:36 MDT Print View

Maybe solar works best if it charges a battery at whatever current it produces.

Then, use that battery to charge your device at the current required.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: Latest, Lightest Solar Charges? on 08/26/2013 21:43:23 MDT Print View

"Maybe solar works best if it charges a battery at whatever current it produces."

Not exactly. For most rechargeable batteries, there is an optimum charge current, and that is generally in the ballpark of one-tenth of the maximum available output current of the battery, but for ten times the time period. This varies from one battery chemistry to another.

Solar panels work best in charging batteries if you use a charge controller.


James Couch

Locale: Cascade Mountains
Re: Latest, Lightest Solar Charges? on 08/28/2013 09:44:13 MDT Print View

+1 Jerry!

In particular most smartphones need something in the range of 7.5v to charge, when they don't get that they disconnect. Solar panels fluctuate the voltage output depending on how much sun they are getting. Charging a battery that has an integrated controller is the answer, charge the battery during the day, use the battery to charge the phone at night.

Goal Zero is one company that seems to really have solar figured out.