Recommendation for portable Solar Panel

mrwhite1

mrwhite1

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I posted this in HID section but haven't gotten much response so I thought I would see if someone here could help me, granted I'm not sure which section this post would be best placed.

In a nut shell, I'm wanting to get some portable solar panels for a go bag. I figured I'd try to get something that would charge my biggest rechargeable item.. which happens to be my Surefire Beast II HID.

I will preference that I dont have any electrical experience, so please forgive my ignorance in terms of volt, watt, mA, etc...

I have been looking for some type of portable solar panels, and was wondering if anyone had any experience with them? I had originally been looking at the Brunton ones http://www.brunton.com/catalog2.php?cat=200 or http://www.powerenz.com/store/, but there are so many other brands thought I would ask for opinions.

I know the Beast II charging case has an input for 12V, 110/220 AC, and battery terminal connections. I notice that several of the solar panels can do 12V or use a inverter to AC... but there are so many differences in the wattage / mA... what should I be looking for? Can someone recommend a particular panel that would work?

From some of the information I've been reading, for example on laptops, they recommend running panels to a battery, then a inverter off battery which would allow you to use the actual power cable for the laptop.
Since the Beast has both adapters I'm not sure if charging AC vs DC what the advantages / disadvantages would be. I'm assuming you can charge faster via DC, but Im not positive.

The Brunton panels I was looking at all say 12V, but the amount of watts and mA are different. For example: The Brunton Solaris 26 is 26 watts (15.4 volts / 1600 mA) the bigger Solaris 62 is 62 watts (12 volts / 3100mA).

Or I could maybe couple the panel with one of their batteries and inverters and charge it that way, and let the panel recharge the battery...
http://www.brunton.com/catalog2.php?cat=200
http://www.brunton.com/product.php?id=604

It's all way over my head and it a bit overwhelming. Any help would be greatly appreciated.
 
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ama230

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I have a few years experience with alternative energy power systems and have extensive knowledge in the field as this is my profession, which I truly love!!! Then again its not going to well as we consume too much power with old ac systems and deem these ineffective for the time being and it stinks to see such a promising technologies such as this suffer right now. Great to see someone taking a stab at it as it awesome and very responsible. Enough with the jibber jabber....

Get one that is amorphous(lower efficiency thin film) as it will work better in all conditions rain or shine. These have a higher current at lower sunlight levels and do not require direct sunlight to get a great output. These are usually the darker panels that look purplish.

Be advised that poly crystalline,mono crystalline and CiS gallium nitride are great but usually do the worst when it comes to days with little light and sundown and sun up.

Here is a great little panel that folds up and has the amorphous panels that would work great and its portable.

These are the cheapest you are going to find these as they easily go for 80-100bucks and they use CiS Panels which have a higher efficiency but mind you that their working time is the 5 hours max the sun is directly above to give direct lighting. The amorphous can do from sun up to sun down(8-10hrs + of collection photons), rain or shine and the efficiency is only 5%max less but the extra hours is collects of light will more than make up for it(due to it being able to collect diffused and reflected light and direct sunlight). The others have a great absorption of the sunlight spectrum but it suffers in doing it in a limited range of the spectrum.

The amorphous has a very broad absorption of the spectrum but suffers in efficiency, its a give and take as this is the most well rounded processing of silicon and requires the least amount of refinement, hence the cheaper $/W. As in this case most have the conception of the more money i spend on it the longer it will last and produce more power. It can sometimes apply but you have to watch who is the maker like sanyo or sunpower etc, these are very vital as the rate of decay is going to be much less with the great manufacture panels like ones listed.

They are both 12V but the larger one carries more current:

This is the 5w one.No cables These also seem to have sunpower for the panel manufacturer, which is one of the best out there in terms of 6 sigma and iso standards etc(quality control) as you can be buying bunk ones like imitation stuff.
http://cgi.ebay.com/5-Watt-Folding-...344?pt=LH_DefaultDomain_0&hash=item255ceaeac0
Then this another 5w but it rolls up... Also comes with all the cables...
http://cgi.ebay.com/5-Watt-Flexible...422?pt=LH_DefaultDomain_0&hash=item2c565a6006

Here is another one that is rated 7.5watt at 12v: This one folds like the first one and has a nice look to it. No cables
http://cgi.ebay.com/7-5-Watt-Camo-F...512?pt=LH_DefaultDomain_0&hash=item2c567fd638

The brunton ones are great quality but marked up too much. All panels these days are from the same manufacturer like sanyo, just like the surefire and icon deal, its how its marketed and presented. You can also adjust power output by folding it in half to get or 1/4 to appropriate voltages and current.

Also you do not need an inverter as you want to keep this strictly dc to dc as this is where most people go wrong and solar stinks. There is a typical 20-40% power loss when converting dc to ac. You can charge a 12v car battery with this thing easily, with either of these panels you choose. Also you can power a smart charger but for total power that you need you could put a couple of them together.

Here is another form the seller as he has a few as these are the same as the powerenz but half the price. Also you should just buy a 12v power brick for your laptop as the inverter is going to rob some of the power being collected. This would also require you to get a smaller setup as you do not need the 42watts with an inverter, you could go with a 25watt with a 12 dc power supply and this would save you alot more money.
42watt:
http://cgi.ebay.com/42-Watt-Foldabl...498?pt=LH_DefaultDomain_0&hash=item2c56dea79a

This is also preference as its up to you to decide on what size you want as I would get something that is typically larger as who knows what you might run in the future. I am definately saving up for one of these to charge my 4runner battery when its sitting as when you trickle charge it, it will last over ten years when maintained vs 1-2 years typical max here in the extremes of Arizona, its the constant over discharge from it sitting and then the parasitic drain from the cars PCM(which is very little but takes a toll in the 190+ degrees it gets from sitting in the sun)...

Hope this helps...
Eric
 
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VidPro

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i find exactally the opposite to be true.
the bendable solar cell items had less than 50% of the watt per INCH of the glass stuff, and didnt work good enough without full sun, and aiming them at the sun.
Based not on the voltage but the amperage that they output.

for same projects i would have to have 2x the square area, and a tracking system, and in the clouds might just as well roll it back up.

But of course this all has to do with HOW they assemble the package. do they use 22V to do a 12v charging? or just 18V , and other such things.

If your not going to break it, for me its glass or nothing, the plastic not only didnt work good enough, but it is plastic , so it is said the lifetime that it will live in the sun will be much less.
plus they say you can bend them, but look closer at the instructions and specs, if you bend them they internally break inside, they have a specific ammount they can be bent before you start causing small internal failures.
so the idea of stuffing them in a backpack , didnt seem to good either.

plus the glass should be the kind you see them big crystals in, not that dull black junk they put in some cheezy stuff, there is a name for them monocrystaline or something, the 12-15% efficency type.

i have my own home built and portable hand built solar pannels for various needs, plus some of them small things that charge internal batteries, and only the glass cells will (for example) still charge behind the window , in non-direct sun. Those particular items i just ignore, as they of course arent charging fast, but they do stay charged.

so if you werent totally confused before, now you can be :)

you should get one that is easily 2 TIMES what you would need for surviving, the more conversions (of any sort) that have to go on, the way more losses you will have. if your trying to CHARGE 12V you need a higher voltage potential than that, like 16-18v, BUT if you have an Input Requiring 12V then your pannel shouldnt be much over 12V like 14.4V max.
pannels for charging RATED at 12V for charging 12V are WAY over 12V
pannels for Running 12V items off of them are not.

the ratings for items that convert for charging phones and such are loaded with balony, just like other ratings, they might list the total pannel , as if that has anything to do with what will be avalable to your cell phone for example. it wont.
pannels are often also Rated at SHORT amps, direct short ammeter ratings, which are about worthless to reality, then they will use those SHORT amps to aquire thier Watt rating, which you will never see unless your going to Short it out too :)
Its baloney because once shorted you dont have the volts (do you) so how do they do 2 seperate meter readings instead of both readings at the same time as would represent the actual watts . lies all lies :)

then they will use a converter that has a 40% loss in it and still be listing the crasy short ratings of the pannel. so you gotta watch out for that. or you will be standing there with a nice solar rock :)

the voltage of the solar pannel doesnt change MUCH when the quantity of sun changes, the amperage it puts out changes like Night and day.

Volts X Amps = Watts ,your going to need to know that, so start using it already.

I've been reading, for example on laptops, they recommend running panels to a battery
not because you cant run a laptop with solar, but because you cant run a laptop with the Solar they sell and you can afford to buy :) without charging a battery FIRST for 10 hours, then draining it in 30 minutes with the laptop :)

same thing with the solar chargers for phones and stuff, they put a battery in, because they dont have enough solar out.

for raw solar power get lots of raw solar energy, or you will be charging a battery with a battery, plus loosing 50% of it it with a converter :)
 
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ama230

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i find exactally the opposite to be true.
the bendable solar cell items had less than 50% of the watt per INCH of the glass stuff, and didnt work good enough without full sun, and aiming them at the sun.
Based not on the voltage but the amperage that they output.

for same projects i would have to have 2x the square area, and a tracking system, and in the clouds might just as well roll it back up.

But of course this all has to do with HOW they assemble the package. do they use 22V to do a 12v charging? or just 18V , and other such things.

If your not going to break it, for me its glass or nothing, the plastic not only didnt work good enough, but it is plastic , so it is said the lifetime that it will live in the sun will be much less.
plus they say you can bend them, but look closer at the instructions and specs, if you bend them they internally break inside, they have a specific ammount they can be bent before you start causing small internal failures.
so the idea of stuffing them in a backpack , didnt seem to good either.

plus the glass should be the kind you see them big crystals in, not that dull black junk they put in some cheezy stuff, there is a name for them monocrystaline or something, the 12-15% efficency type.

i have my own home built and portable hand built solar pannels for various needs, plus some of them small things that charge internal batteries, and only the glass cells will (for example) still charge behind the window , in non-direct sun. Those particular items i just ignore, as they of course arent charging fast, but they do stay charged.

so if you werent totally confused before, now you can be :)

you should get one that is easily 2 TIMES what you would need for surviving, the more conversions (of any sort) that have to go on, the way more losses you will have. if your trying to CHARGE 12V you need a higher voltage potential than that, like 16-18v, BUT if you have an Input Requiring 12V then your pannel shouldnt be much over 12V like 14.4V max.
pannels for charging RATED at 12V for charging 12V are WAY over 12V
pannels for Running 12V items off of them are not.

the ratings for items that convert for charging phones and such are loaded with balony, just like other ratings, they might list the total pannel , as if that has anything to do with what will be avalable to your cell phone for example. it wont.
pannels are often also Rated at SHORT amps, direct short ammeter ratings, which are about worthless to reality, then they will use those SHORT amps to aquire thier Watt rating, which you will never see unless your going to Short it out too :)
Its baloney because once shorted you dont have the volts (do you) so how do they do 2 seperate meter readings instead of both readings at the same time as would represent the actual watts . lies all lies :)

then they will use a converter that has a 40% loss in it and still be listing the crasy short ratings of the pannel. so you gotta watch out for that. or you will be standing there with a nice solar rock :)

the voltage of the solar pannel doesnt change MUCH when the quantity of sun changes, the amperage it puts out changes like Night and day.

Volts X Amps = Watts ,your going to need to know that, so start using it already.

I've been reading, for example on laptops, they recommend running panels to a battery
not because you cant run a laptop with solar, but because you cant run a laptop with the Solar they sell and you can afford to buy :) without charging a battery FIRST for 10 hours, then draining it in 30 minutes with the laptop :)

same thing with the solar chargers for phones and stuff, they put a battery in, because they don't have enough solar out.

for raw solar power get lots of raw solar energy, or you will be charging a battery with a battery, plus loosing 50% of it it with a converter :)

The reason you got the readings you did with the past flexible panels are because they are the poly crystalline and are a thick film panel and not very flexible and require direct sunlight to get moderate power. These were not amorphous and these are the thinnest ones and usually cheaper due to less refinement and doping. You will know whan you see a quality amorphous panel as it will have a great color to it and will put out more power in all conditions, period!

You have to get name brand panels such as powerfim or sunpower or sanyo as they actually have quality control an testing for guaranteed results.

The same thing applies with batteries as sanyo is the best and the majority of others over claim.

Amorphous are the darker purplish panels that look like Gallium nitrides with less reflectivity due to more opaqueness. These absorb much more of the spectrum of light than all others and with this versatility the efficiency suffers but has more current being generated in doing so. This in effect has more electron holes being filled and thus when more electrons are moving then we have more current.

All other panels have a max 5-6 hours of effective photon collection vs the 8-10 plus hours of the amorphous, then this would equal more power being generated over a longer period of time. Also the amorphous will collect more power in low light conditions and is usually cheaper in terms of $/watt.

It seems to me that you had bought bunk poly crystalline panels as these are decent for the $/W but suffer in terms of versatility and productivity.

You have to watch what companies you buy from as they usually stick with the same manufacturer. Stick with a reputable one as the listed above and guarantee you will not have any problems. The panels i listed have reverse power protection with a diode and most panels you have to add this in as when the potential of the power source you are trying to power has more, it will damage the panel(small arrays burn out one by one as a panel is a conjunction of multiple tiny arrays to get the specific voltage and current characteristics) Then a result in loss of efficiency follows.

The quality panels also have a anti reflective film on them to help and majority just have a shiny glass cover which throws photons to the curb. You can tell by tilting the panels in the light and you will see colors like you would when you have polarized sunglasses when looking at window tint. Also looks like the same color of when soap is on top of water and has the purplish multi color coolness. This is a very big factor as at least a 1/3 of the light being reflected and not used.

If you need current = Amorphous or thin film panels

If you need voltage = Poly(cheapest) or mono crystalline, or Copper Indium Sulfide or if you can afford it Gallium Nitride.

Also for your battery in a solar charger comment:

They use this as a buffer for power output as a small panel is maybe a 1w at the most. These always use cheap polycrystalline panels(cheap quality and not saying they are always junk) which is very poor to charge batteries as you need current over voltage in this situation.

In terms of overall a quality amorphous and 12v plug will beat any other panel in terms of flexibility and usefulness. Also they are meant to be flexible to wrap around something and not be a piece of paper as this is left over silicon from IC manufactures making wafers we are dealing with.

We have yet to see a ultra thin film make it in terms of spectrum absorbency. As the problem with making it too thin is the photons travel through the medium and do not get used, that why some have even gone to making multiple layer panels and this is why they are so thick and have to be guarded in glass to protect from flexing. Multiple junctions = no flexing period.

The mono or poly do not collect ambient light the amorphous do as well as direct sunlight so in terms of versatility and cost amorphous is the best.
 
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VidPro

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Ama230 you tell me that they make a flexable pannel that has 15% efficency in power conversion, and point to the exact pannel, and i will give them another try.

i have ones with a dark purple cast to them, and they werent cheap at all, and they suck. so if your telling me that everything has somehow changed, i will try them again, because these are older.

The mono or poly do not collect ambient light the amorphous do as well as direct sunlight
many amorphous pannels have built in bypass diodes, and therfore can cope with shading sitatuations.
But
there isnt one place on the web, even from sellers, that would say a amorphous is anywhere near as efficent as even a poly.

show me ONE research paper even from the manufacture or seller that makes the claim that that they have a flexable pannel of any sort, that Per square foot can supply more energy at any level of light.
you have to have a KITE :) of these flexable pannels , and that is what it becomes out in the wind :)
 
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ayglass

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Gentlemen,

This is proving to be a very educational thread. Thank you both. You have rekindled my curiosity about entry level solar power.

Thanks!

- Andy
 
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ama230

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Ama230 you tell me that they make a flexable pannel that has 15% efficency in power conversion, and point to the exact pannel, and i will give them another try.

They aren't going to have the efficiency of a mono or poly or any thick film panels. If you clearly read what I said, I listed the pros and cons.

They collect more light in a given day and therefore more power is produced. I did not state that efficiency is better. As is the most efficient thin film panel is 10%, these are cheap and easy to come by. Then a quality poly is maybe 13-15% but you have to pay a premium for these as these take more refining and take a higher quality silicon. The overall size of a house roof will need less mono panels for higher power but you have to pay on upwards of 5$/Watt and then an amorphous is going to take a little more space and going only to cost 1-2$/W. When you have a 10kW system, you have to pay 50k vs the 10-20k and you will get more power throughout the year in all conditions.


i have ones with a dark purple cast to them, and they werent cheap at all, and they suck. so if your telling me that everything has somehow changed, i will try them again, because these are older.

You have to research and find the manufacturer of the panels because these are produced super easy and quality control is very high in name brand panels, like the ones i listed.

The mono or poly do not collect ambient light the amorphous do as well as direct sunlight .

Direct - When the sun is within a 45+/- degree angle of the perpendicular plane(Directly over, as this is hard to do when the earth is tilted+/-15-30 degrees side to side depending on seasonal tilting and location) Only mono/poly/cis/gan are effective in this condition. They have a thicker substrate and a sometime multiple layer to catch the majority of the photons, hence the higher efficiency.

Diffused- When the sun has ambient light out. Light is being evenly dispersed as its reflecting off everything. Think of a lense that is smoked on a flashlight lens as it will give a diffused light output and mono and poly do not perform well with this, then their efficiency would go down below an amorphous.
Amorphous is great in this and direct sunlight(not as good in direct since the efficiency is less being a thin film as photon pass right through the thin film, not a lot but some and this is why the efficiency goes down) This is also why they do great in low light conditions as the light is less intense and is able to catch more photons, without being penetrated.


Many amorphous panels have built in bypass diodes, and therefore can cope with shading situations.

The non name brand ones do not, there are only a few great manufacturers that do this. As its cheaper to have a few at a buck and replace them, then making a really good one that takes 10 bucks to make that is going to cause the customer to not need to buy anymore. YOu have to watch this as this is the case with all replicas.

But there isn't one place on the web, even from sellers, that would say a amorphous is anywhere near as efficient as even a poly.

There isnt going to be as they have different purposes. This applies as the new cree XP-G is supposed to be the most efficient at the time but does not put out as nice of a beam or run as long as previous models. This only has one purpose as its the most efficient but does not do what it needs to be competitive. The amorphous puts out higher current and a lower volatge, the others are vice versa(this is where they put more power out).
Measure a mono or poly when its cloudy and then an amorphous then you will see, this is for overall power output in all conditions. The mono or poly is useless in low light conditions and this is where the amorphous makes up.


show me ONE research paper even from the manufacture or seller that makes the claim that that they have a flexable pannel of any sort, that Per square foot can supply more energy at any level of light.

Calm down and read what i said earlier as you are reading into it too much. Its clearly there. 10+ hours of collecting light(Amorphous), 5hrs of collecting light(mono/poly/cis/GaN). The crystalline modules are limited by the amount of time they get direct sunlight(when the sun is directly over the panel and has less than a 45 degree pitch from exposure all the way up to ninety(which is perpendicular to the panel). An amorphous works from a little before sun up to a little past sun down with collecting light.


you have to have a KITE :) of these flexable pannels , and that is what it becomes out in the wind :)

You can only have one of the two when it comes to today's panels.

1)absorb a major part of the light spectrum. Amorphous hence the current as its absorbing more photons to displace electron holes with electrons. These are generally the most rugged as well as their lattice structure is not as tight as a mono or ploy etc, hence being able to be flexible.

2)Have a high efficiency with a limited absorption of the spectrum. mono/poly/cis/gan etc

You should try and read up on some of these technologies as its very interesting and would further validate what i am saying.

Also think of an old calculator that is able to work in any light condition with its small amorphous panel. A mono or poly etc cant do this as it needs a very good exposure to a light source, hence the strong need of direct sunlight.

Maybe the terminology is somewhat not clear. Ask me nicely and ill clear it up as I cant when you are calling me a lair or saying what im saying is not true. Cut me some slack and ill help break it down to where you can understand as this is an awesome technology and is very under rated.


 
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ama230

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Gentlemen,

This is proving to be a very educational thread. Thank you both. You have rekindled my curiosity about entry level solar power.

Thanks!

- Andy

Do not be discouraged as with anything it takes time and proper exposure. In the class room they make it very foggy as they have a hard time understanding it themselves. This is my opinion makes is very unpleasing to get into, then seeing real world applications and doing small projects, you will pick this up quick while saving a few thousand(more than this but i like to make it not sound like a lot) i spent on an education at ASU Polytechnic.

Read up on all types of panels to get a general over view as then you can compare and contrast and see the relationship. They have their strngths and weaknesses but it depends on what you want them to do. They have matured but then again they are not getting the exposure they need in order to drive cost down, we can thank the president i voted for, for this.:thinking:

Small steps as its alot to grasp, there is more to this subject than just stating efficiency and most power. Quality control and manufacturing will take years to get a hold of.

Great to see your interested as its a very fun, safe and responsible technology.
ERic
 
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VidPro

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ama230, hey were just repeating the same things back and forth.
i have been running solar Experimentally for 10 years, and 10 years before that i piddled with it educationally. i get my readings from measuring live actual items purchaced for the projects.
i have also defied some of the problems and issues they present in some of the studies, by better cooling, better power backflow blocking, and other cheap tricks. on the other hand , there are not a lot of trees here (new development).


AS the sun comes up, Not before (like your saying) one simple pannel is already recharging my battery at a 70+* angle although not anywhere close to a large ammount. i cant wake up before it is already reading a current flow :tired:. 100+ times a year i am seeing this meter showing this information to me. so i am like indeed NOT understanding, but i read it the first time. It also does amasing ammounts of charging during full block cloudy days , much more than i expected.
It has built-in raw voltage and ammeter,It has no day tracking and only a seasonal azmith change capability. and i am in california.

I believe that you have information that i Need to see.
i am asking you to point me to a specific very High efficency single flexable pannel item, so i can test what your saying, that will certannly guarentee that it will do what your saying. not just any thing you find , ONE very specific prime choice of yours. because i would like to try it.
 
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paulr

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For a go bag it makes no sense. With normal sunlight you have to use that solar stuff for weeks or months before it generates enough energy to equal its weight in batteries. If you use your go bag in a bad-weather event (hurricane and peripheral storms), expect no sunlight for a while. Plus even with sunlight you pretty much have to stay stationary while using the panels.

If you've got a 12V charger already, charge from a vehicle if 110vac is not available.
 
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mellowman

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For a go bag it makes no sense. With normal sunlight you have to use that solar stuff for weeks or months before it generates enough energy to equal its weight in batteries.

If you only use 1 AA battery a day then yes, maybe a few weeks worth but not months.

Lets do the math. A lithium primary 1 AA L91 battery weighs about 15g. The 5 watt panel that ama230 first linked to says it weighs 7 ounces ~= 200g. So the weight equivalent of the panel is 13.33 L91 batteries. 1 2700mah NiHm battery weighs 30g so the weight equivalent of 1 rechargeable AA and the 5 watt panel is 16 L91 batteries. Or 16 days of 1 AA battery use a day.


However, if you used say 4 AA batteries a day then the math is:

200g (panel) + 4 x 30g = 320g / 15 g = 22 L91 batteres / 4 per day = 5.33 days.

Though I have neglected the weight of the AA charger, say 2 oz or 60g or 4 L91 batteries which would add another day @ 4AA/day. So lets say 1 week is panel + 4 2700mah AA rechargables + charger = 26 L91 batteries. Cost wise it is about the same so if you need longer than a week going solar starts to make sense in both cost and weight.

Also if your demand is more than 4 AA bats or you want to charge a notebook then you need a larger panel and forget about trying to charge it with primary batteries.

Bottom line it really depends on your demand and how long you expect to be without power.

If you use your go bag in a bad-weather event (hurricane and peripheral storms), expect no sunlight for a while. Plus even with sunlight you pretty much have to stay stationary while using the panels.
Yep, true which is why you should definitely have enough primaries for a day or two or three. If you need go longer say after the event to rebuild, clean up or whatever then solar starts to make sense.

If you've got a 12V charger already, charge from a vehicle if 110vac is not available.
Well, gas may be more important to get aid, water, food or other supplies and even barter with.
 
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diriel

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Bookmarked this thread. I will have to do some digging. Fascinating!

Gary
 
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paulr

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If you only use 1 AA battery a day then yes, maybe a few weeks worth but not months.

Lets do the math. A lithium primary 1 AA L91 battery weighs about 15g. The 5 watt panel that ama230 first linked to says it weighs 7 ounces ~= 200g. So the weight equivalent of the panel is 13.33 L91 batteries. 1 2700mah NiHm battery weighs 30g so the weight equivalent of 1 rechargeable AA and the 5 watt panel is 16 L91 batteries. Or 16 days of 1 AA battery use a day.
Yes, do the math. 5 watts is the absolute peak power you'll get at high noon on a cloudless day. When you take into account nighttime, varying sun angle, clouds, season, latitude, etc. you're doing ok if you get 10% of peak power averaged over a 24 hour period, so 0.5 watts average, or 12 WH/day. That's actually better than I thought: you can charge 2 or maybe 4 cells in a good day, assuming you can set up the charger in a stationary place outdoors with no occlusion. If you're on the go (it's a "go" bag after all) or have to be indoors a lot, all bets are off.

Well, gas may be more important to get aid, water, food or other supplies and even barter with.
If you're driving the car someplace anyway, running a nimh charger won't use enough power to affect fuel consumption. Running the car just to charge batteries is a different story, of course. Either way, you'd use a 15 minute charger so a typical errand would be enough to charge 4 cells. With a 300 watt inverter you could run several such chargers at once.
 
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mellowman

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Aug 20, 2009
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157
Yes, do the math. 5 watts is the absolute peak power you'll get at high noon on a cloudless day. When you take into account nighttime, varying sun angle, clouds, season, latitude, etc. you're doing ok if you get 10% of peak power averaged over a 24 hour period, so 0.5 watts average, or 12 WH/day. That's actually better than I thought: you can charge 2 or maybe 4 cells in a good day, assuming you can set up the charger in a stationary place outdoors with no occlusion. If you're on the go (it's a "go" bag after all) or have to be indoors a lot, all bets are off.

Well, glad you see that it can work and I'd personally go with something more than 5W even if it was just to charge AA bats. Point is that the tradeoff point is a matter of days not months as you suggested.

However, one should still have enough primaries to get through the 72-hour period. After that you are either chilling at some hotel/resort, at a refugee center or heading back home to clean up or rebuild. In the later two you are or will be stationary and you might be there awhile and electricity may be hard to come by for awhile so solar can make sense.

This doesn't effect me personally and wouldn't be my choice but as evident in the aftermath of Katrina those who have only what they can guard/keep stay with what they have to avoid having nothing. For those in those situations or making that choice again solar is a viable option.

If you're continually running from the Zombie Apocalypse or something then yes solar is not a good idea. Don't forget to double tap!

If you're driving the car someplace anyway, running a nimh charger won't use enough power to affect fuel consumption. Running the car just to charge batteries is a different story, of course. Either way, you'd use a 15 minute charger so a typical errand would be enough to charge 4 cells. With a 300 watt inverter you could run several such chargers at once.
Don't know of any 15min charges that really do it in 15min but I get your point and yes one could take advantage of the power produce by ones car when running errands. Though multiple chargers would make driving challenging with all that clutter inside. Also something could happen to your car so it would be best to have an alternative.
 
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mrwhite1

mrwhite1

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*There have been some lost replies to the forum, I am attempting to restore them from emails that I have, I appologize for the incongruency*




Lynx_Arc

---Quote (Originally by mellowman)---
Don't know of any 15min charges that really do it in 15min but I get your point and yes one could take advantage of the power produce by ones car when running errands. Though multiple chargers would make driving challenging with all that clutter inside. Also something could happen to your car so it would be best to have an alternative.
---End Quote---
I was without power for over 4 days and you don't have to have a 15 minute charger, I had a 1 hour charger that was designed for 1800mah cells charging 2300mah cells and I would charge 2 sets of 4 cells in about 3 hours with the car sitting in the driveway not running then I would take another set with me while running errands and after a few hours they would be charged. Your car battery has plenty of capacity to charge batteries and with 100 amp alternators in cars today the battery can be recharged of what you took from it while off rather quickly, relying on a fast charger to only charge while the car is running isn't a good strategy and those chargers reduce the life of batteries most of the time so much that almost nobody uses them. I would not use a 15 minute charger unless I was limited to time borrowing someone else's power.
 
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mrwhite1

mrwhite1

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I appreciate all the solar education! The reason I'm wanting it is for emergency purposes / camping / or crime scenes where resources might be limited. I want something that i can leave in my vehicle and be able to charge my laptop or HID searchlight if need be. These items dont utilize traditional AA or 123 batteries so having extras really isn't an option. I do carry several additional batteries in my usual edc for my regular flashlights.
This wont be used for every day carry, but I will have it in my vehicle if needed. I spoke with a gentleman from http://www.powerenz.com/store/. Extremely nice and helpful. He instructed me to be most scientific for determining what I need is to order a Kill-A-Watt meter (<$25). That way I can plug my items into it and then determine exactly what the power requirement is for charging them. Once I get that, he said he can help me determine which of their systems will best meet my needs. Anyone every use any of these products or the ones from Brunton?
 
mrwhite1

mrwhite1

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ama230

I appreciate all the solar education! The reason I'm wanting it is for emergency purposes / camping / or crime scenes where resources might be limited. I want something that i can leave in my vehicle and be able to charge my laptop or HID searchlight if need be. These items dont utilize traditional AA or 123 batteries so having extras really isn't an option. I do carry several additional batteries in my usual edc for my regular flashlights.
This wont be used for every day carry, but I will have it in my vehicle if needed. I spoke with a gentleman from http://www.powerenz.com/store/. Extremely nice and helpful. He instructed me to be most scientific for determining what I need is to order a Kill-A-Watt meter (<$25). That way I can plug my items into it and then determine exactly what the power requirement is for charging them. Once I get that, he said he can help me determine which of their systems will best meet my needs. Anyone every use any of these products or the ones from Brunton?

The kill-a-watt idea is is a great one!
Also Brunton has a great product and all of their products i have owned have never had any problems.
They use the amorphous panel as well as a mix of the CiS thin film panels(these have a higher efficiency than amorphous and have the same characteristics of an amorphous).
I have to correct what i said earlier and CiS does not require only direct sunlight, i got my facts messed up as i was going off the top of my head but the rest still applies and is 100% factual.
Both thin film technologies - They do great in all light conditions. They do not only need direct sunlight/ bright sunny day.
The amorphous - has a lower efficiency but is affordable in terms of $/Watt and has a high current and low voltage characteristics.
CiS or CiGS(some with and without the gallium) - These have the same characteristics of an amorphous but they have a higher efficiency which rivals mono and exceeds poly. These are hard to come by cheap and when you do find one get it. This is the best all around panel around, then again you are going to pay primo for it. Also heat degradation is very high on these and this is why I have chosen the amorphous to be the overall best in terms of price and performance.
Brunton seems to be a solid product and it seems that they would use sanyo or sunpower panels which are the top tier and are the best. They have a great lifetime at a rated 20-30 years and this states that it will only loose 10% every 10 years of its claimed output. This is the same if not less that other cheap panel manufacturers.
To choose between products you should go with either powerfilmsolar or brunton as these are going to be the most rugged and give youthe best performance in all conditions.
First do the kill a watt thing and then source between these two companies and see what meets your needs in style and power requirements.
Hope this helps.
Eric
 
mrwhite1

mrwhite1

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This is all of the information i could find, I may still be missing a few responses unfortunately. Please keep the solar education coming!
 
cottonpickers

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Here's how I would charge that monster ;-) .....

1. I'd start by getting a nice simple regulated 12v car/lorry lead that plugs in to the cigarette lighter. Should give you some nice portability quick and cheap and will be needed later. (lorries run at 24v, so a charger that runs in either a 12v car or a lorry is a great start)

2. Next, get pretty much any solar panel rated at between 12v and 24v and put a car cigarette socket on the end. The more ma rating, the quicker it will recharge your flashlight. Remember, the regulated lead will take the 12v-24v solar voltage and regulate it to 12v nicely. Personally I wouldn't worry too much about Mono / Poly / Amorphous - I just would go for the nicest looking / best size / price combination that you like. This should now give you a fair bit more portability as you can charge it anywhere you can carry the panel - or sit at the back of your car charging away happily.

3. For more portability / reliability when the sun goes in,you could get a small 'AGM' (no liquid to spill and sealed) 12v battery and small solar "charge controller" to make sure you don't overcharge it. Then even if the sun goes in the small (maybe 12ah) battery can still put some juice in your flashlight. Alternatively get one of those 'jump start' battery chargers / compressors - they have a 17ah battery in them and a 12v socket - can also use it for other puposes then.

Generally if you are using solar, you need to avoid lots of voltage converting (avoid 12v --> 120v -->12v) which inverters lead to as you waste all that precious energy.

None of the panels I sell will be of any use to you with that monster light:eek:, but I certainly do think that solar is a viable method of charging batteries on the go. Its just a case of getting a good match for you needs.

For many people a 2w panel is easily carried, yet can put back 400mah into a li-ion in one hour. I don't think thats too shabby :)

Good luck with your solar search...
CP
 
A

asval

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This is all of the information i could find, I may still be missing a few responses unfortunately. Please keep the solar education coming!
yes please do, this is a most informative read lovecpf and I haven't even read all of it yet :eek:

gonna print it out and keep reading it later on
 

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