Is there a solar charging faq?

The battery university is good. Is there something similar for solar charging. I'd like a solar setup for 18650s but I don't know enough to choose among cotton pickers products.

Or, more specifically, I have an Intellicharger i4. I read that it does not like variable 12v voltage. So I need something to stabilize the input. Looks like some solar setups have a battery bank to store up the energy but that implies to me that they have a charger that accepts variations of a solar panel.

Backpacking/sailing setup is goal. But general education also helpful.

Obviously confused. Any help or links appreciated.

Thanks in advance.

Tom

I have never heard of such a site. Possibly, this is because solar charging is a relatively new thing. But there are certainly many different approaches one may take to this. I myself use a Suntactics panel. Unlike many solar chargers out there, this one is NOT a 12V panel. It's a low voltage/high current panel designed around USB charging for phones, tablets, etc. I use this panel to charge with an Xtar MC1. It's not the fastest setup, since the MC1 can only charge at a half an amp. But it works. Plus, the panel works GREAT on phones and tablets (the panel puts out over 2A). What would REALLY be nice is a USB Li-ion charger that can charge at higher than .5A (at least with this setup). But I'm not sure such a charger is available.

Check out Portable solar charging setup I just built...

Norm

bluedog225 said:

The battery university is good. Is there something similar for solar charging. I'd like a solar setup for 18650s but I don't know enough to choose among cotton pickers products.

Or, more specifically, I have an Intellicharger i4. I read that it does not like variable 12v voltage. So I need something to stabilize the input. Looks like some solar setups have a battery bank to store up the energy but that implies to me that they have a charger that accepts variations of a solar panel.

Backpacking/sailing setup is goal. But general education also helpful.

Obviously confused. Any help or links appreciated.

Thanks in advance.

Tom

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Hi Tom,

I think if you go to www.aspectsolar.com and check out their "Energy Bar" and their EP-55 Solar Panel to recharge the Energy Bar (it can also be recharged from AC) I think you'll find the solution to your challenge. You can plug any recharger into the Energy Bar.

LetThereBeLight!

bluedog225 said:

The battery university is good. Is there something similar for solar charging. I'd like a solar setup for 18650s but I don't know enough to choose among cotton pickers products.

Or, more specifically, I have an Intellicharger i4. I read that it does not like variable 12v voltage. So I need something to stabilize the input. Looks like some solar setups have a battery bank to store up the energy but that implies to me that they have a charger that accepts variations of a solar panel.

Backpacking/sailing setup is goal. But general education also helpful.

Obviously confused. Any help or links appreciated.

Thanks in advance.

Tom

Click to expand...

I've seen this question a couple of times. The issue with hooking a charger straight into a solar system is that most chargers don't necessarily operate within the wide voltage range of a solar panel. They basically just tell you that it takes a 12v input but don't really tell you the range that it will operate in.

Or some will just be a USB type of charger which isn't as efficient. A USB based charger is a 2 step charger converting whatever its input is to 5v and then from 5v to lithium-ion is via linear charge mechanism which isn't as efficient as going straight from solar to the battery being charged via switch mode technology.

The other issue is that a charger operating off of strictly solar needs to be able to lower its charge rate for when the sun is weak or you are using small panels. Some things to be aware of but its doable.

I just couldn't find anything that I really liked and met my specifications so I ended up designing my own charger. It runs on voltages from 7v min up to 25v. You could hook it straight into a solar panel if you wanted without a 12v battery. It has 3 settings: 200mA, 500mA and 1000mA. It's controlled by a microcontroller. It has adjustability for the termination voltages. Thus if they come out with new batteries with a higher than 4.20v termination, I will adjust it. It also has a built in voltmeter for viewing either current or voltage. It utilizes switch mode technology for efficiency. It has reverse battery protection and it has extremely low (as in a micro-amp or two) of parasitic drain when a battery is left in.

You'd have to get a hobby charger to get the functionality that I have but then you wouldn't have the simplicity, light-weight and the portability.

Anyhow, not sure I'm ready or willing to mass produce these as its quite an expense......but I did end up with a few extra bare boards if you have assembly capability .

bluedog225 said:

Backpacking/sailing setup is goal.

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Is it really more space-efficient to lug around a charger and solar panels, than it is to just carry extra batteries? I get that a solar setup is fun, but if I was backpacking, I'd just bring along extra batteries or make sure my stuff ran on AA's which can be bought anywhere.

WalkIntoTheLight said:

Is it really more space-efficient to lug around a charger and solar panels, than it is to just carry extra batteries? I get that a solar setup is fun, but if I was backpacking, I'd just bring along extra batteries or make sure my stuff ran on AA's which can be bought anywhere.

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It depends on where you are going, and for how long. Extra batteries can only get you so far. Plus, they can easily weigh more than a solar charger. When it comes to backpacking, you could be out in the total middle of nowhere for a REALLY long time (especially out here in the West). You might not be able to buy batteries. And when they're spent, you're in the dark. Plus, extra batteries can add even more weight if you also want to use them to charge gadgets like phones.

StorminMatt said:

It depends on where you are going, and for how long. Extra batteries can only get you so far. Plus, they can easily weigh more than a solar charger. When it comes to backpacking, you could be out in the total middle of nowhere for a REALLY long time (especially out here in the West). You might not be able to buy batteries. And when they're spent, you're in the dark. Plus, extra batteries can add even more weight if you also want to use them to charge gadgets like phones.

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If you're out in the middle of nowhere where you can't even find alkaline batteries for sale, you're not going to have cell phone service, so you may as well save the space and leave it at home. I can see your point if you're hiking out west where you're guaranteed sun. On the east coast, you're a bit at the mercy of the weather when it comes to solar charging. And what if your charger breaks? If you're depending on batteries, you probably still have to bring extras to be safe.

But yes, if you have the space, a solar charger means you don't have to conserve power. I just think that when it comes to multi-day backpacking, weight and space means everything. The only stuff I'd carry was stuff that had multiple purposes and was as light and small as possible. If I wasn't 100% sure I would need it, it gets left behind.

WalkIntoTheLight said:

If you're out in the middle of nowhere where you can't even find alkaline batteries for sale, you're not going to have cell phone service, so you may as well save the space and leave it at home. I can see your point if you're hiking out west where you' <---Snip

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What about times of national disaster when batteries are sold out and there is no mains electricity?

Norm

Norm said:

What about times of national disaster when batteries are sold out and there is no mains electricity?

Norm

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I would personally minimize use of electronics, and fast-charge the ones I need from the car. However, that certainly has limits. The advantage is that it uses things I have without buying anything else.

Solar power can be tough - The application defines the parts needed, and most useful electronics require some steady power output. For example, a battery charger will act a bit squirrelly if its own power varies and blinks off sometimes.

Norm said:

What about times of national disaster when batteries are sold out and there is no mains electricity?

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Sure, but that's a different situation than hiking. In a fixed location, size and weight don't matter much, and you can have a solar charging station for emergency use or perhaps in a hunting cabin that has no grid power. I can certainly see solar charging being useful in a trailer or cabin that isn't hooked up to the grid. I'm not sure in an emergency situation it would be very important... by the time I run out of batteries (they'll last weeks) I'm probably dead because gangs have come and killed me for any food or supplies I have.

AnAppleSnail said:

Solar power can be tough - The application defines the parts needed, and most useful electronics require some steady power output. For example, a battery charger will act a bit squirrelly if its own power varies and blinks off sometimes.

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Have you seen my solar set-ups the first charges with a 40nWatt panel Here and Here?

I have some experience with solar. I also have a cotton Pickers panel which will run direct ML-102 on a sunny day

For a fixed solar charging station, would it be easier to use a panel to trickle-charge a deep-cycle SLA battery, then use the 12v DC to power a regular charger (with a cigarette lighter plug)? Then you don't have to be concerned about intermittent power and voltage. And, of course you can run other stuff off the 12v feed as well.

Lots of good info to digest. Thanks everyone.

bluedog225 said:

Lots of good info to digest. Thanks everyone.

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It's been said that any panel(s) over 20w combined probably needs a digital controller, which can be $20 affairs up to something like $70+ for my Morningstar PWM SunSaver 10-L.

This regulates your voltage and helps to keep things in a 'safer' voltage range.

You can see what I have in Norm's link, which combines his elegant solution with my 'not so' elegant setup, lol.

Mine is more for 'hurricane season' and isn't necessarily a backpackable jobbie.

Chris

Norm said:

Have you seen my solar set-ups the first charges with a 40nWatt panel Here and Here?

I have some experience with solar. I also have a cotton Pickers panel which will run direct ML-102 on a sunny day

Click to expand...

Wow! You are smarter than the average solar bear, though. I saw a "Recharge your laptop" solar mousepad scam once. Definitely the opposite end of the solar smarts spectrum.

Hi there. I have some experience in the field: on my vacation I like to go mountain biking in the desert. My solution to this problem is:

-Solar panel (folding as Brunton Solaris 6 or rollable like as Powerfilm 13).
-Power bank (4x18650 or 2x18650 battery).
-Battery charger.

I have a standard USB connector and use the same socket to charge the powerbank and with it, power the battery charger. You can also use a powerbank that has adjustable output 12v to operate a charger as the Nitecore. The only big problem with a setup like this is the time to charge the powerbank, because with a smaller panel of 10 watts takes too long to finish the job. The larger the panel, the better, but that requires an increase in the size and weight of luggage. Finally, it all depends on your energy needs. To me, this has worked well for me a couple of flashlights with 18650 battery, one with 16340 and one with an AA, a GPS 2xAA and my cell phone and a PDA (all this without ever deplete these batteries).

You could also connect the panel to a voltage regulator (such as those sold in DX and other stores) and then plugging it into the input 12v powerbank. To use a SLA battery may be better to use a charge controller, but this increases the size and weight of the configuration.

One has to take travel breaks to recharge the batteries. If you want to be in motion is more complicated, since the change of position of the panel will greatly affect the charge. On my last trip I used a small backpack hanging panel for a few hours and did not get to notice an increase in the charge level of my powerbank (had only 25-50-75-100% charge indicators, so probably charged less than 25% I not have a multimeter to check the state of charge either, but I intend to wear it on my next trip.).

CPF4 by Teobaldo Mercado Pomar, on Flickr

(The photo is from a previous trip, where I stopped to eat, is only for reference)

Caution: Most panels can deliver more than 12v. My Powerfilm and Brunton go up to 19V, so the use of a controller / regulator before reaching the battery is necessary.

Hope that helped a little and sorry my english (I can hardly write, it's not my native language, but I like to give my experience to others).

If you need massive light then you'll need big solar panels, but if you just want enough light for trail walking, hanging around the campsite - cooking reading emergency survival etc., then there is now a solution with a fully integrated Powerfilm solar charging system in a handsfree headlamp. check out link removed
Solar charging is great to have some battery independence, saves pollution, cost and the sun will always be there.