Solar powered battery chargers???

[CaptainpPicardX]

Hey guys, I'm still new here, but anyway, I was looking around on the net, trying to find a good solar charger for my batteries. I have pretty much left behind buying alkaline batteries for good. At the same time I like to prepared for emergencies, which often times include power outage. I have a few thing for ER's that run on batteries. I really hate trying to find batteries during/after a disaster, people hoarding, not to mention trying to find a store thats open, so a solar charger would be a lot of help,... But, anyway,...


Are there any good Solar batter chargers out there, especially ones that can charge AA,AAA, and even 18650's? I know 18650's is a long shot, but how bout just AA,AAA and/or C,D cell?

Thanks, Denis.

 

[TEEJ]

Cottonpickers is what you want. Go to cpfm and find his thread.

 

[ChrisGarrett]

At 60w, it'll even run your laptop while you're surfing CPF. That's an Xtar WP2 II charging a couple of Soshine 16340s, IIRC.

http://www.candlepowerforums.com/vb/showthread.php?342073-Portable-solar-charging-setup-I-just-built

Brunton, Global Solar/Sunique, CottonPickers, PowerFilm and Goal Zero all make foldable/rollable panels in the 5w-62w range. For batteries, phones and smaller things, 20w and a controller will get you started. 26w-27w, would be better, as you loose watts via inefficiencies. US Armed Forces are using the PowerFilm 30w and 62w panels, so they're milspec.

Chris

 

[rpm00]

Take a look at Goal Zero products as well. Very high quality. I have the 7W panel and Plus pack and love them.

 

[CaptainpPicardX]

WOW, what a giant pain in the ***, not that its too complicated I like fooling with wires, but still... Over $200 waiting for different parts, etc... I cannot believe no company put this whole thing into a single small portable product?! So basically from the Very quick research I have just done, you cannot directly power up the charger with panels? you have to charge the golf cart? battery first? so you are actually powering the battery charger (btw I got that same chrager two weeks ago myself) With the GC battery, and just using the panel to keep the GC battery charged in the first place?? Still cant believe there aint no easier way... Oh, well, I might have to come up with one..

 

[hiuintahs]

I've got a setup similar to ChrisGarrett. with solar, You really need a storage battery and then from there you can run a USB or 12v input charger. That way you can pick any 18650 charger or AA/AAA charger that has a low voltage (USB or 12v) input. My setup is just getting built right now and haven't had a chance to try it out other than I did measure the voltage and short-circuit current one day out in the sun. I've got two 80 watt foldable panels, an Xantrex C35 charge controller and a 52 amp-hour deep cycle AGM battery.

The problem with the small solar setups is that I'm not sure how some chargers react to intermittent power input unless they are desiged specifically for solar and can re-start in case a cloud floats over and causes the voltage to drop out that was running the charger.

I'm currently working on the design of a 18650 charger that will be able to handle such a situation. I have a 12v to 3v dc adapter that I power my Lacross BC-700 with when working with the 12v power (solar or auto).

 

[ML2013]

I have a Goal Zero Nomad 7, it's total crap, i've looked into solar chargers since my bad experience with goal0, it weighs about 13oz and measure about 2.5 watts at a 5 volt output which equals .5 Amps of output current.. which is nowhere near enough to solar charge a cell phone at a decent rate, it'll take more than a freakin day to fully charge a smartphone! So i then got my hands on Suntactics sCharger-5, weighs 8.3oz and it pulls 1.0 Amps at 5 volts, plenty for cell phones and rechargeable batteries. I use it to charge my iphone, which fully charges it in 2 hours with no problem. You can look around online to find USB rechargeable AA/AAA batteries, i've seen some on ebay that could charge 4 batteries that has a USB connection.

 

[Aperture]

Double the Watt rating of what you need and you're pretty safe. The problem is that the specified Watts are measured without a load and when you actually start charging something the actual produced Watts are 25% lower plus you'll have a 25% loss for the battery charging process itself. Going bigger than twice the needed power rating assures better performance in less than optimal conditions.

As an example my 4W USB panel measures 0.8A @ 5V with the multimeter on the open connectors which is the advertised 4 Watts but when it charges something it drops to 0.58A @ 5V which is only 2.9W.

Knowing the charging specs of your charger (or devices with a built in charger) is key to get the right panel as this is the limiting factor of how much power can actually be used. The iPhone 4 can only handle a 0.72A @ 5V which is a mere 3.6W, a 27W panel will not fry it but is a bit overdone, 7W should be the minimum and a 10 to 12W panel is perfect to be on the safe side.

It's also advisable to use a regulating batterypack between the panel and the charger to ensure a constant charge on the charger in case a cloud obscures the sun, etc. Be sure to use a pack that supports pass-thru or load balancing, with this feature the power that gets in goes out the other side without charging the internal battery which would result in a 25% loss. When more power comes in than is needed it will store the excess power and when the panel can't deliver enough power it will supplement it for a constant output.

Personally I prefer all my chargers and sources to be compatible with the USB format as it's the smallest most universally used power socket and you can use other sources besides solar like the BioLite stove and PowerPot cooking pot.

This is my off the grid charging solution sance the sources:

The Voltaic V11 pack transforms the 8.4V input from the Nikon EN-EL15 DSLR battery to a 0.9A @ 5V to charge the 18650 3400mAh in a ML-102 USB charger (max 5W) which charges another EN-EL15 battery in a Pixo C-USB (max 4.5W) multi charger (3.7 & 8.4 Li-Ion, AA, AAA). The 18650's are used in my Surefire lights or Spark headlight, they also serve as my backup power (I'll bring 2 to 10 spares depending on the length of the trip).

My big solarpanel is a Voltaic 16.8W panel btw, when using a dual USB car adapter in the 12V socket I can charge two USB chargers at once with ample reserves for less than optimal light conditions.

That said I prefer to bring enough batteries with me to last me the whole trip as the sun doesn't shine that much during hiking season in Northern Europe, with the setup posted above I can use whatever charge I have in my 18650's or DSLR batteries to charge anything else if needed.

 

[reppans]

I have a Goal Zero Nomad 7, it's total crap, i've looked into solar chargers since my bad experience with goal0, it weighs about 13oz and measure about 2.5 watts at a 5 volt output which equals .5 Amps of output current.. which is nowhere near enough to solar charge a cell phone at a decent rate, it'll take more than a freakin day to fully charge a smartphone! So i then got my hands on Suntactics sCharger-5, weighs 8.3oz and it pulls 1.0 Amps at 5 volts, plenty for cell phones and rechargeable batteries. I use it to charge my iphone, which fully charges it in 2 hours with no problem. You can look around online to find USB rechargeable AA/AAA batteries, i've seen some on ebay that could charge 4 batteries that has a USB connection.

In all fairness, GZ specifically states it maxes out at 2.5w through its USB port. It is designed for optimal integration (6+ watt) with its Guide 10 4xAA battery pack. If the OP uses that Suntactics 5w panel with a third party USB 4xAA charger, my guess is that you'll end up with longer charge times. The Suntactics certainly seems the better choice for direct charging to USB devices though.

 

[ChrisGarrett]

WOW, what a giant pain in the ***, not that its too complicated I like fooling with wires, but still... Over $200 waiting for different parts, etc... I cannot believe no company put this whole thing into a single small portable product?! So basically from the Very quick research I have just done, you cannot directly power up the charger with panels? you have to charge the golf cart? battery first? so you are actually powering the battery charger (btw I got that same chrager two weeks ago myself) With the GC battery, and just using the panel to keep the GC battery charged in the first place?? Still cant believe there aint no easier way... Oh, well, I might have to come up with one..

You can simplify things by buying the 62w PowerFilm foldable unit. They run about $800+, but they're a lot more portable than my setup. I guess you could daisy chain two 30w panels together for about $840, or three 20w panel, for $900, lol.

I'm in hurricane alley here in Miami and I wanted something that could charge things up when the power goes down. I don't want to be waiting around for hours on end, like one would be when using smaller panels. I don't need this to fit into a backpack, just be light enough (22# total w/chargers) to carry downstairs, or pack into the truck if I need to haul a$$ out of town.

My little system does that and with another 'mother' battery, or two, I don't even have to run down everyday and set the thing up.

Chris

 

[Spork]

Another informative post

http://www.candlepowerforums.com/vb...-of-Eneloops&p=4055819&viewfull=1#post4055819

I picked up the ccrane solar charger but have doubts about its reliability. I've considered putting something together with a 20 - 30 watt panel for charging eneloops or phones. The powerfilm panels are ridiculously priced though and if your go with a nice LiFeO4 battery to save all that energy its going to cost some money. Also for me it would mostly be a backup for extended power outages and would rarely be used.

It would probably be much more practical to use a car charger for me anyway and put that extra money toward more eneloops. If we had to some of these flashlights can last for over 20 hours on a single aa. My wife has several portable usb chargers as well.

 

[ChrisGarrett]

Another informative post

http://www.candlepowerforums.com/vb...-of-Eneloops&p=4055819&viewfull=1#post4055819

I picked up the ccrane solar charger but have doubts about its reliability. I've considered putting something together with a 20 - 30 watt panel for charging eneloops or phones. The powerfilm panels are ridiculously priced though and if your go with a nice LiFeO4 battery to save all that energy its going to cost some money. Also for me it would mostly be a backup for extended power outages and would rarely be used.

It would probably be much more practical to use a car charger for me anyway and put that extra money toward more eneloops. If we had to some of these flashlights can last for over 20 hours on a single aa. My wife has several portable usb chargers as well.

Yeah, I don't know about the Crane solar dohickey. If you want cheap, but not really portable, go with a rigid panel, as the warranties are generally 10 yrs @ 90% rated output and 25 yrs @ 80% rated output. Foldable/Rollables come with either 2 yrs (Brunton Solaris) and 3 yrs (GZ, PF and Global Solar/Sunique), so we're not talking about a lot.

Rigids are also much cheaper and and more efficient, depending on what 'type' you get, than the flexi-panels.

Also, you can save some cash by getting basic SLA/AGM batteries in the 12Ah-18Ah range for 'mother battery' duties, for not a lot of cash and they'll be fine for charging smaller stuff and you'll get 3-5 years out of them. The boutique stuff is nice on paper, but for charging batteries, smart phones, GPS, iPad type things, you can save some money, by buying standard stuff, IMO.

Chris

 

[Sub_Umbra]

I'd recommend a 12v AGM battery and a solar panel with as good a charge controller as you can afford. The Morningstar Sunsaver 10L is a great controller used by industry in remote sites and harsh marine environments all over the world (over 1 million units in the field) and it's in the ~$50-60 price range. With the above setup you may use any charger that has a 12vdc input for mobile charging. I like the Accumanager 2020 for charging with AGMs.

I also like small AGM scooter batteries in ammo cans. Very handy for charging phones and running small LCD TVs when the power is out. I just ordered an 18AH scooter battery from Amazon for $21.99 with free shipping. It'll charge a phone quite a few times.

Our serious hurricane season where I live doesn't really start 'til August. I bought a big ammo can that I'm going to fit out with a 35AH AGM scooter battery. I may make more if I like the way it comes out. After Hurricane Isaac last year I began working on smaller systems that may just be carried outside when the power goes out.
---------

Almost forgot. I had one of the CCrane chargers when Katrina rolled through. The one with the Fresnel lens. It was $15-$17 IIRC when I got mine. Because I bought it partly for the potential entertainment value involved in figuring out how to make it work if I ever needed it I never even took it out of the box when it came.

In the following six weeks that our power was out I used it to charge AA NiMH cells so we could listen to Audiobooks. It works. Mine is still in the storm kit even though I have a much bigger panel now. It's a 'dumb charger' so you'll have to do some math and time it's use. A multimeter is handy.

Multiple units would be much better than just one.

 

[IonicBond]

I'm also into the backyard 12v nominal panel / controller / battery setup, but I find the most convenient just for AA's is the small foldable PowerFilm four-AA charger.

What I like about it so much is that it seems to take into account solar conditions that involve passing clouds / shadows without repetetive harsh EOC termination triggers. Under normal use, it will fully charge up to about 80% SOC quickly, and then do a slow charge. If it is already at 80% SOC and a cloud / shadow is encountered it seems to just go back to a slow charge. Thus, kind of like the Maha C9000, for the most capacity, count on charging for at least 2 more hours when the red led charge indicators are solid and not blinking.

There is also a combo 2AA / USB powerfilm charger, but I find that the USB function is just too little of any real use with only 2 AA's, and have had the usb port burn out. The 4AA only charger is my favorite for portability AND seeming to take care of AA's well.

There is still the matter of having cells out in the sun or indirect heat if you shade the top portion, so take that into account - on 90-degree plus days, I pull them when the indicators are solid and forego the 2 hour top-off.

 

[Spork]

How long can the agm batteries sit unused? This is something I probably won't use very often.

So far the setup I'm planning is

LiteFuze 30w panel , Morningstar Sunsaver 10L , for the battery I was considering a UPG 85980/D5722 Sealed Lead Acid Battery (12V; 35 AH; UB12350) It doesn't say if its agm. There is also a similar 7ah battery and wonder if that would be big enough. For the charger a MH-C401FS.

Also what kind of fuse do I need and where does it go? This will be my first experimental setup. Maybe I should go with something smaller? The instaspark panels have some complaints in reviews and the 10 watt powerfilm is expensive. The litefuze seems to be in the middle for price.

 

[Sub_Umbra]

How long can the agm batteries sit unused? This is something I probably won't use very often...

AGMs are very LSD.

...So far the setup I'm planning is

LiteFuze 30w panel , Morningstar Sunsaver 10L , for the battery I was considering a UPG 85980/D5722 Sealed Lead Acid Battery (12V; 35 AH; UB12350) It doesn't say if its agm. There is also a similar 7ah battery and wonder if that would be big enough. For the charger a MH-C401FS...

The next battery I order will be the UB12350. It is an AGM. I'm going to install it into an 800 crtg 5.56 m27 link surplus ammo can I just picked up. If I like it I'd like one or two more...

Below is a link to the UB12350 spec sheet:

http://preview.tinyurl.com/cbmbplp

7AH is pretty small. While many online write about drawing down AGMs to 40 to 50% (which may certainly be done at the cost of some service life) I try to design my stuff so I don't have to go below the 80% sweet spot where I may get many more charge/discharge cycles.

...Also what kind of fuse do I need and where does it go? This will be my first experimental setup. Maybe I should go with something smaller? The instaspark panels have some complaints in reviews and the 10 watt powerfilm is expensive. The litefuze seems to be in the middle for price.

Everyone's needs will be different but after letting the 'magic smoke' out of a wiring harness I tend to put fuses everywhere. In general you have at least two things to protect: fuses to protect each device and fuses to protect your wiring harness. If your fuse is too big to protect your wiring, your wiring becomes the fuse.

For my uses automotive blade fuses have been working well for me, but as always, if I was smarter I might use something else. /scratches head

I've had AGMs over the years but I've really just started experimenting with the smaller ones in the last six months. Wheelchairs and scooters have made them cheaper to play with.

One last note: Keep the wires from the Morningstar to the battery to two feet or less. You not only want the temp sensor on the Morningstar in proximity to the battery, you also very important to minimize any wire induced voltage drop between the controller and the battery. Your run from the panel(s) to the controller may be longer but for the health of your battery the run between the controller and the battery needs to be short and the largest gauge wire that will fit on the controllers terminals.

 

[Rexlion]

I have a couple of chargers that came with 12v 'cigarette lighter' style plugs. My travel trailer has such a receptacle built into it, overtop the kitchen counter. I recently went to Solar Blvd and bought a W Solar 75w panel for under $100, and a Morningstar controller for about $25. Wired it up so it plugs into the trailer's pigtail (that plugs into my car normally, but now it's attached to the solar) and it is not only maintaining my trailer battery, I can charge 4 NiMH cells anytime.

See, all you guys need is a travel trailer...... :devil:

 

[SemiMan]

How long can the agm batteries sit unused? This is something I probably won't use very often.

So far the setup I'm planning is

LiteFuze 30w panel , Morningstar Sunsaver 10L , for the battery I was considering a UPG 85980/D5722 Sealed Lead Acid Battery (12V; 35 AH; UB12350) It doesn't say if its agm. There is also a similar 7ah battery and wonder if that would be big enough. For the charger a MH-C401FS.

Also what kind of fuse do I need and where does it go? This will be my first experimental setup. Maybe I should go with something smaller? The instaspark panels have some complaints in reviews and the 10 watt powerfilm is expensive. The litefuze seems to be in the middle for price.

6-12 months of standby if the battery is kept cool, 3 months if the battery is kept warm. It also depends on the quality of the battery.

The UPG is an average quality battery. 99% certain this one is just private labelled for them, so hard to say exactly what quality. Their data sheets are limited in details.

In terms of panels, so many of the panel names I hear thrown around, LiteFuze, W Power, etc. are just meaningless rebrands. Most of these companies (based in China) will out of business well before the panel warranty expires, but fortunately, panels are pretty simple so short of dropping them, you are likely to get at least 10 years, but then again, initial power may not be to spec. In the U.S. I generally suggest people buy from Sunelec as at least you have some initial purchase recourse. They have been in business a long time and I think they plan to keep it that way. There are others out there that are reputable as well.

Can't emphasize enough to buy ONLY a name brand charge controller. It is plain stupid to pay $100 for a battery and hook it up to a $20 controller. The controller is the only thing keeping your battery alive and many do a poor job of charging a battery.

Always keep in mind with any lead-acid battery is that they like to be 100% charged all the time (or close to it), so charge them fully as soon after use as you can. Sulfation in the top 75% of the charge tends to be low, but increases beyond that. They also like to be cooler. Heat (>35c) quickly kills lead acid batteries. Of course cold temps and a poorly compensated charger is also a death knell to batteries.

If getting larger panels (100w ish), consider an MPPT charge controller as you usually gain another 25% out of the panel. Unfortunately good ones are still pricey.



Semiman

 

[hiuintahs]

My AGM battery sits around for months on end without being used and I just put a top off charge on it about once every couple of months. Like SemiMan says, best to keep lead-acid batteries mostly charged up. I use a Xantrex Truecharge 10 for that when AC is available. Solar is for if/when the power goes out for any length of time.

Semiman had some good comments and I'll throw in some more about MPPT vs PWM vs cheap charge controllers. MPPT will cost twice that of a good PWM charge controller. Though an MPPT does take advantage of maximizing the power output of a solar panel, the only difference between that and a good PWM controller as far as getting the job done is time. If the solar panel is needed to be working all the time, then it makes sense to have an MPPT type. But if just pulling the panel out occasionally to charge up the battery, then it really doesn't make economic sense to have a more expensive MPPT type controller. MPPT type controllers really only are worth getting on a solar system that is in constant operation which usually is only on bigger (non-portable) systems.


A PWM charge controller that is made by a good reputable company and that adheres to 3 or 4 stage battery charging.......bulk / absorption / float / Equalization, would be very adequate. Now the cheap charge controllers...........I wouldn't trust a good AGM battery to them.

This isn't a plug for Morningstar or Xantrex but I like both and both are very popular and very reputable and I have researched them. The Morningstar 15A MPPT charge controller is just above $200. The Morningstar Sunsaver 10L PWM is $70.00. The Xantrex C35 MPP is around $100.00. I think it depends on how big your system is. I'd size the charge controller to handle at least double the rated solar panel current just to be on the safe side of reliability.

 

[IonicBond]

Note about the Morningstar Sunsavers and AGM absorb voltages.

The default jumper select is between sealed and flooded. Since nearly all of my AGM's in cyclic mode want to see a 14.7 volt absorb voltage, I actually run with the jumper removed because per the manual and measurements, that actually provides a 14.7v absorb. Even though it seems frightening to run an agm in the "flooded" setting, I say take a look at the actual voltage spec of the jumpers and see if interpreting the actual voltage, and not the silkscreen is more appropriate.

For me, "sealed" is more like 14.1 volts, and is more applicable to gel, or when running mostly in float mode. Cyclical semi-daily use, and with limited solar-insolation hours, I run with the 14.7v absorb by removing the jumper for my AGM's - the UB12350, PowerSonics and many others.