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best solar charger right now? march 14"
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Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: maui, hi, solar charger on 03/11/2014 20:59:38 MDT Print View

"So what is the best one for my Samsung galaxy?"

As was posted earlier...

"...you really have to get in touch with the power demands of your devices. Without that, you are just spinning your wheels."

You need to determine how much capacity you are using each day, and how many days you will be out, and at a minimum how much juice you need to push back in. I have been to Hawaii several times and it always seemed to rain part of the time I was there.

Tony L
(Luch0623) - M
WakaWaka power on 03/11/2014 21:31:35 MDT Print View

You may want to check out the WakaWaka power. I got mine through a kickstarter campaign like a year ago for like 40 bucks. I think they sell now for like 60. They are small, semi lightweight at 5.15 oz (on my scale) and also have a built in light. You can charge it via USB or solar. Mine takes a full day or a little more to get a full charge. I have a Samsung s4 and if my phone is completely dead the WakaWaka will charge it to about 75%. I then just strap it to my pack and at the end of the day it will be near 100% charged (it charges quicker in full sunlight but still charges in the shade or when overcast). I never use my full battery in one day because I am careful so I never have problems using the WakaWaka. I may be wrong here but when I bought it i think it was the most powerful solar charger for its size.

FYI there is also a waterproof dry bag it comes with that is an additional 1.35oz. You don't want to get the solar side wet. I have used in on 4 trips last summer and it withheld each trip. It seems to be very durable too. Worth checking out IMO

http://us.waka-waka.com/

Edited by Luch0623 on 03/11/2014 21:34:29 MDT.

Derek M.
(dmusashe) - M

Locale: Pacific Northwest
Re: Re: best solar charger right now? on 03/12/2014 18:29:26 MDT Print View

I have no direct experience with solar chargers, so I can't provide any first hand reviews.

With that said, I recently dug into this topic myself and came to conclusion that the Suntactics sCharger 5 is the one of the only moderately lightweight solar panels on the market that isn't totally underpowered for charging smartphones. People using this panel in real world backpacking conditions reported being able to charge their phones to 100% in a half a day of full sunlight.

I also got the impression that no solar panel worked very well in anything other than direct sunlight. So overcast conditions or extensive forest hiking would preclude the use of a solar panel for backpacking.

Don Amundson
(amrowinc) - M

Locale: Southern California
Solar Charger on 03/12/2014 18:58:43 MDT Print View

I'll be the 4th or 5th or... vote for the Suntactics sCharger 5. I hike with a couple of friends that share one for their multitude of electronic items and constant facebooking. It does the job for both of them. The beauty of it in my mind is that it's a direct USB connection so your not charging a battery pack to charge your device. As these things go the weight isn't too bad.

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:11:30 MDT Print View

Found a few on amazon this one for $30, 7200mah, 8 ounces, looks durable has a carabiner etc : http://www.amazon.com/Poweradd-trade-Apollo-Portable-USB-charged/dp/B00DLUYSPO/ref=sr_1_2?ie=UTF8&qid=1394770020&sr=8-2&keywords=solar+charger+usb


Lots and lots of choices, I dont need much, I think ill probably be happy with a lightweight 8oz~ and under $50 charger. Pretty excited to buy one soon!

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

Locale: Silicon Valley
Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:15:44 MDT Print View

The problem with that last one is that you don't know how much replenishable power is coming from the solar panel, and how much is coming from the internal battery. Those solar charger marketing guys don't miss a trick.

--B.G.--

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:28:32 MDT Print View

It says it can charge a device while charging itself in the sunlight. But yes upon looking more into it its made to charge by plugging into a wall? What is the point of the solar panel then? I dont know. ill keep looking.

I want something small and light that can charge itself, and that has a built in battery with decent juice. Or else I would always need to have my device plugged into the solar panel if it didnt have a battery itself.

hmm, all I need is a 8 ounce solar charger, it would be nice if it had a built in battery. I dont know what I want honestly, I didnt realize how many configurations there can be. If anyone knows what I need/ good setup let me know please!

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:35:42 MDT Print View

Solar for Backpacking?

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:46:30 MDT Print View

That little battery you linked to has a solar panel, sure, but run the numbers on it.

It's a 7200 mAh battery. The panel puts out 180 mAh MAX. So even in direct sun, running at peak efficiency, it would take 40 hours to charge up that battery. At 10 hours of high-noon desert sun, that's 4 days.

The reason you can't find quite what you're looking for is the same reason we can't either. It doesn't exist yet.

For 8 ounces, you can have either a decent panel, or a 7000 mAh battery, but you won't get both. Wish it wasn't so, but that's where it stands as of today.

On the upside, if you're going to spend 8 oz on a 7 amp battery, one with a little solar booster is the way to do it.

Edited by Glenn64 on 03/13/2014 22:56:38 MDT.

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

Locale: Silicon Valley
Re: Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 22:57:32 MDT Print View

If you have a solar panel set up in Nick's backyard where sunlight is highly reliable, you might put up a solar panel without any intermediate battery, and just charge your devices directly. However, if you are in more normal places where there is some sun and some shade and some clouds, then often you can't get a high enough current coming out of the bare solar panel to charge your devices. In that normal case, putting the intermediate battery in there will help your charging operation continue. But, if you don't ever know how much power your solar panel is capable of, or if you can't separate that power from the battery itself, then you are just spinning your wheels.

If the solar panel specs say that it will produce 5 watts or 10 watts, then that is a hard number that means something. You will still need to get some direct sun to produce that wattage, but that is a good target to shoot for. For a backpacker-size panel, something like 5 watts or 10 watts is what you might be looking for.

On the other hand, if you cut your overall electrical usage down, you might be able to complete your trips with just one spare battery carried, or something like that. But if you don't even know what your overall electrical usage is, you are still just spinning your wheels. Statements like, "it's to run an XYZ smartphone" are absolutely silly.

--B.G.--

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 23:19:46 MDT Print View

Michael,

You said, "I am really not wanting to spend hours teaching myself about these and reading reviews."

and

"...all I need is a 8 ounce solar charger, it would be nice if it had a built in battery. I dont know what I want honestly, I didnt realize how many configurations there can be. If anyone knows what I need/ good setup let me know please!"

It doesn't work this way. First you MUST determine how much energy you use each day. Even if two people have the exact same phone and/or devices, they energy use will vary because they are not going to use them the same.

Then you need to estimate how much power you need to put back each day. It can be less than you use, depending upon how long your are out.

Then you need to guesstimate how much energy you can realistically generate each day, which varies by where you are, what the weather is, what the time of year it is, your orientation to the sun, will you stop for maximum sun exposure, etc., etc., etc.

No one can answer these questions for you.

I have a trailer that we camp in for up to 2 weeks at a time. It is solar powered. I have to have a strategy to cover sunny days or two weeks of overcast skies. Too little sun for too long means I have reduce my consumption. Sunny days in July means I can do anything I want to include running a microwave, toaster, blender, and a 32" Television with a DVD to watch a movie. But I know how many amps have been consumed and how many amps have been put back in.

You are going to need to make an effort in this search.

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/13/2014 23:29:50 MDT Print View

Nick, I will be using about %75 of a 3,200mAh battery per day. This is a Smasung Galaxy mega 6.3. Hope this helps, thank you!

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: best solar charger right now? march 14" on 03/13/2014 23:47:48 MDT Print View

http://www.amazon.com/Opteka-BP-SC6000-Capacity-Charging-EcoPanel/dp/B00CHQI57A/ref=sr_1_6?s=wireless&ie=UTF8&qid=1394775713&sr=1-6&keywords=solar+charger+usb

The one above is a 6000mah battery with a solar panel. $29.99

I imagine it will take a while to charge, but once charged it holds a lot of power. Is this what I want? Not sure.solar

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: best solar charger right now? march 14" on 03/13/2014 23:55:07 MDT Print View

http://www.amazon.com/Poweradd-trade-Apollo2-10000mAh-Dual-Port/dp/B00FXWGRHU/ref=sr_1_17?s=wireless&ie=UTF8&qid=1394776322&sr=1-17&keywords=solar+charger+usb

This one ^ is 10000mah and $45, seems super compact and 9oz, seems good?

I doubt the solar panel works fast, but with a battery that big I wont be relying on the panel as much right?

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

Locale: Silicon Valley
Re: best solar charger right now? march 14" on 03/14/2014 00:20:56 MDT Print View

Here is a good rule of thumb for solar panels:

You can get about 10 watts of output from about one square foot of panel. Some are better than this, and some are worse. If you are looking at a product that doesn't produce 5 or 10 watts, you are probably looking in the wrong direction.

One guy calculated that he needed a 5 watt solar panel to meet his device power needs. Then he did the JMT and complained afterward that the panel didn't work worth a damn.

The problem was that he had it hanging off the back of his backpack, so it was facing north most of the time while he was headed south. If he had planned on taking several zero days with the panel facing south, he would have gotten completely different results.

--B.G.--

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Re: best solar charger right now? march 14" on 03/14/2014 00:30:05 MDT Print View

"I imagine it will take a while to charge"

No need to imagine, it's rated at a maximum 250mAh charge rate from the panel. A 6000 mAh battery would take 6000/250 = 24. So 24 hours of full sunlight to charge it.

"but with a battery that big I wont be relying on the panel as much right?"

Again, no need to guess at this stuff, it's all pretty straight forward. You said you would be using 75% of your 3200 mAh battery per day, that's 2400 mAh, or about 25% of 10000. So it would be good for four 75% charges.

You'll never get optimum solar charging rates, and you'll never get precise battery drains, but good ballpark figures are really just that simple, once you know what your requirements are, like others have stated.

Just be sure when doing battery and panel comparisons, that you're using the same voltage specs, in this case 5 to 6 volts. It's a pretty standard range for the type of application you're looking into.

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Re: Re: best solar charger right now? march 14" on 03/14/2014 00:44:00 MDT Print View

Just to chime in and emphasize what others keep saying, too many people think that solar panels work from some sort of wizardry, or elvish magic. They think as long as the sun's up, there's free power flowing through the wires at maximum rated capacity. There's this belief that's it's as regular as a wall socket. Nothing is further from the truth.

A solar panel in the shade makes about as much power as a wind generator on a calm day. It just doesn't happen. Oh sure, it may make an itty bitty tiny miniscule amount just from ambient light, but unless it's in DIRECT sunlight, any of these little panels just don't do much of anything.

So all the ratings and specifications in the world don't mean squat, unless you factor in all the variables involved. Solar is unreliable at best, which is where batteries come in. The battery is the buffer, to keep the juice flowing. Whenever constructing any kind of solar system, big or small, you have to build from both ends, increase production and reduce consumption. It's a balancing act, and the battery is just the middle man.

Edited by Glenn64 on 03/14/2014 00:47:15 MDT.

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: Re: Re: Re: best solar charger right now? march 14" on 03/14/2014 02:23:15 MDT Print View

Lots of great info. thanks for the replies.

I think im going to get this apollo2 10kmAh battery pack with solar. If it will charge my phone 4x I should have plenty of time to keep it charged within 4 days with the 250 or 200 solar charge time. Very compact and good juice.

It also has a flashlight and a carabiner and looks like it belongs outdoors. Seems legit. 9.4 ounces. I like it...

http://www.amazon.com/Poweradd-trade-Apollo2-10000mAh-Dual-Port/dp/B00FXWGRHU/ref=pd_sim_sbs_e_2?ie=UTF8&refRID=0REKCGZN4BH8AFJFMTWYsolar apollo2

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/14/2014 02:49:42 MDT Print View

I looked into this battery panel charger thingy a bit more. I've not looked into these types of devices before, so I don't know if they're all this way or not, but as I was mentioning about making sure the volts are the same to get reliable information...

It appears to use a pretty common 3.7 volt type of lithium battery. So that makes the 10k mAh rating a bit misleading, since it actually takes about 5.5 volts to charge a USB device.

What that means in the math, is that the 10000 mAh, multiplied by the voltage of 3.7, gives you a total wattage of 37000. Divide the total wattage by the OUTPUT voltage of the USB's 5.5 used by its microcircuitry, and you only get about 6800 usable mAh's.

In short, Amps X Volts = Watts.

So with the magic of marketing, a 10,000 mAh battery, is really only usable for 6,800 mAh's for a USB device.

I know that sounds rather convoluted, but bottom line, is that it's REALLY only about a 6800 mAh battery for your phone.

One of the reviewers on Amazon was complaining about it not being true to spec, which is what made me suspicious and look a little deeper.

Perhaps somebody else can verify these findings, but that's how it looks to me.

Edited by Glenn64 on 03/14/2014 03:23:05 MDT.

michael levi
(M.L) - F

Locale: W-Never Eat Soggy (W)affles
Re: Re: Re: Re: Re: Re: best solar charger right now? march 14" on 03/14/2014 03:25:24 MDT Print View

Interesting observation Glenn. I wonder if all of these from various brands agree like that. Meaning they are all misleading.

Still, if it has 6800mAh then that might be enough for my application. It seems like this should work, the next jump is a bigger 23000mAh and $115 +.

I feel like I will be able to take advantage of the small solar panel on the Apollo 2 with the plentiful sunlight on the islands. Only one way to find out is to test it, I'll probably buy one sunday!