Please help! Trying to 'work with what I have'

[Digital-Freemason]

Hello, I am a disabled cancer survivor - so please don't advise me to buy new or different stuff. If I can't work with what I have, that is my answer. I hope to add to my system over time.

I bought "Photovoltaic Design & Installation for Dummies" and "Solar Electricity handbook 2013 Edition" and read them both through twice+. I understand the entire big picture very well now, Serial, Parallel, Panel to controller to batteries DC to inverter AC etc...;, , but neither book was really any help to me in the real world. A dear departed friend left me a new looking Amorphous type panel. It is 36 by 12 inches.

My question is: with a panel like this (pictures attached), and assuming a need for a simple OFF-GRID SYSTEM to power lights and charge phones during power outages Only;
What level Amp and Volt 'Charge Controller' do I need to charge 12volt batteries and output to an A.C. / USB Inverter?

I see charge controllers with the same general specs for $18 and $180 dollars -that seem to do exactly the same thing. I am Professional Animator, Computer Programmer, Visual Effects Artist, I'm no dummy... This is Very hard to do with such poor information. The Books all explain electrical theory with no practical info, I would be happy with a simple answer that says:
What I have (what my panel is) and What I need (what level 'Amps' and Voltage Charge Controller would work with my panel).

For Instance: If I bought a 4.5Amp - 12/Volt Charge controller, would that let me charge a single battery with my existing panel? Would I need more 'amps' to charge more batteries is that how it works? I have never come across something I didn't kin immediately. The plethora of terms that seem to describe the same thing is confusing. I know they describe different phenomena but I have Never seen a good example, description or illustration that made it clear. So many pages in these books say the same thing but it's never really explained as much as defined. (like spelling bee's "can you use the word in a sentence") BUT: As soon as I 'get it' I am going to Animate a descriptive tutorial that really explains Volts/Amps/Watts so anyone can just 'get it' too. Charge (in battery) and Current (in cable) I get pretty well.. LOL.

Please someone: Use it in a sentence!
Like; "with your single existing panel to charge One battery you need (n)Amps and (n)Volts Charge Controller and (n)? (n)? Inverter.
To add another like panel you would need: (n)Amps and (n)Volts etc.
To add another battery you would need (n)Amps and (n)Volts.

I can't get simple answers that relate to me from these books, but at least I tried the books (and web etc) before asking any question of anybody!

MY EXISTING PANEL I HAVE TO START WITH: (it is 36 by 12 inches.)

IMAG0950.jpg

IMAG0952.jpg

IMAG0953.jpg

Thank you and Happy Holidays!
Check out my CGI Animated Star Trek TOS Film "BEYOND ANTARES" at:

https://www.youtube.com/watch?v=nQeH2xu5l74

[axis11]

Look for ratings on the back of the panel. Vmp=?,, Imp=?

[FunGas]

You really need to know how much power the solar panel outputs before you can plan any other equipment.

At noon, aim the panel at the sun and measure the DC Voltage, open circuit.
Then set the meter to the highest Amperage range and measure the short-circuit current.

A 10A MPPT Charge controller will "probably" do what you need - they can be had for around $25

[Mike90250]

.....A 10A MPPT Charge controller will "probably" do what you need - they can be had for around $25

Sadly, I know of no $25 "mppt" controller that is not junk.

Doubly sad, is that your small, amorphous panel (long, evenly dark segments with interconnect stripes) is likely only capable of 10 - 20 watts, about enough to charge an android phone in 1 day.

[FunGas]

I have one of these types, pretty good for the money, much better than the PWM one I had before (which lasted about 2 weeks).
I use it to charge five 7A batteries with a 150W panel.

[Surf Charter]

Hi Digital-Freemason

Q:If I bought a 4.5Amp - 12/Volt Charge controller, would that let me charge a single battery with my existing panel?

A: You need to know the capacity of your battery. the way to work out the maximum charge rate for a given battery capacity is C/8. A 100amph / 8 = 12.5amp. So you mension that you will be adding on when you can, for example I have 4 x 100w panels, together the max current that I have ever seen from them at noon in sunny Bali is 5.5 amp. thats at 48v, at 12v the amp would be higher, more like 20amp. At that point your 4,5amp charger will be out gunned. Yes for your panel it isnt a problem but how big do you want to go. I would say a 10amp should be a good size that you could add many panels to.

With your panel you dont need a controller, I would connect direct the battery. you need a lot up sun and a lot of time. Good luck.

[greenHouse]

You really need to know how much power the solar panel outputs before you can plan any other equipment.

At noon, aim the panel at the sun and measure the DC Voltage, open circuit.
Then set the meter to the highest Amperage range and measure the short-circuit current.

A 10A MPPT Charge controller will "probably" do what you need - they can be had for around $25

That doesn't give you anything other than Voc and Isc. It does NOT give Vmpp or Impp. The model I use -- just a model, don't quote me on that -- is that Vmpp is about 75% of Voc and Impp is around 90% of Isc. That produces a lousy fill-factor, but if one doesn't have the real numbers, a good guess is better than a bad guess ...

And I'll second the comment about not knowing where one could find a $25 MPPT charge controller.

[FloridaSun]

That doesn't give you anything other than Voc and Isc. It does NOT give Vmpp or Impp. The model I use -- just a model, don't quote me on that -- is that Vmpp is about 75% of Voc and Impp is around 90% of Isc. That produces a lousy fill-factor, but if one doesn't have the real numbers, a good guess is better than a bad guess ...

And I'll second the comment about not knowing where one could find a $25 MPPT charge controller.

I've no experience with it but that $25 'mppt' controller FunGas mentions shows an input voltage max of "12V~20V" ... so would be pretty much useless even if it was really MPPT.
Before switching over to Morningstar MPPT I did have some experience with a cheapo MPPT, this one, with a Vmax input of 45v for a 12v system and it did work as MPPT, converting the extra volts to amps. Not bad for $41 (free delivery, USA stock) but be warned there is no equalize mode or temp sensor or adjustment of any kind besides the timer. Also beware, there are similar cheaper controllers (shipped from HongKong) which look identical except they are only one digit LCD display (the $41 is 3 digit). No experience with them.
Cheap can be fun to play with but anyone wanting to take good care of their batteries should look for quality.

[PNjunction]

Digital Freemason -

You have essentially a 15 watt, thin-film panel. That's capable of about 800ma current on the best of days. While not as efficient as a mono/poly crystalline (it just means that your panel is larger for the same relative output), it won't go absolutely dead if a small leaf or tiny shadow falls across it.

You have a good location for solar insolation. These differ from sunrise-to-sunset hours, and from charts, we know that you are lucky with 6 hours in summer, and 5 hours in winter - provided that these are perfect conditions, ie not cloudy, rainy, smog-haze etc. So far so good.

Battery - with our solar insolation, 800ma of charge current, and a desire not to go below 50% of battery capacity for longest cycle life, we're talking about using a small ups-style AGM battery no larger than 10ah or so (7-12ah ok). That gives you 5ah to play with on a regularly cycled basis, and a chance for a daily full charge. Something like a PowerSonic, Universal Battery etc. Just be sure that upon receipt, the voltage is not much lower than 12.4v, since that indicates that the battery has been sitting around in the retail chain for a year or so.

Don't cheap-out on the charge controller, although why not start with relatively inexpensive quality to begin with? I'd recommend a Morningstar Sunsaver SS-6-12V. This is a quality pwm controller, relatively inexpensive, with temperature compensation to boot. Pull the jumper for "flooded" operations with your agm. Most small agm's want to see 14.7v absorb, but in "flooded" mode, the morningstars are at 14.4v which for this small non-critical application will do ok. The reason I recommend this over the even cheaper SunGuard 4.5A controller is that the fixed voltage is a bit low for agm on this model. The SS-6-12V allows you to remove the jumper to get the absorb voltage up to 14.4v at least.

For charging your usb devices, the easiest thing to do would be to wire a female cigarette lighter jack across the battery, and use one of the many mobile-usb charge adapters. The come in different amounts of current handling capability from .5A to all the way up to 2.1A output - at 5v of course.

Basically you have a small explorer type system at this stage, which should be a lot of fun and provide many hours of multimeter entertainment, phone charging etc.

[Naptown]

What everyone is missing here and I did not see mentioned anywhere is what is the open circuit voltage of the panel in question.
Many are fairly high voltage. So the first thing that needs to be done at this point is face the panel at the sun and take open circuit voltage and short circuit current to see at least a rough idea of what you have.

[thastinger]

What everyone is missing here and I did not see mentioned anywhere is what is the open circuit voltage of the panel in question.
Many are fairly high voltage. So the first thing that needs to be done at this point is face the panel at the sun and take open circuit voltage and short circuit current to see at least a rough idea of what you have.

Agreed. That panel looks like 1/3rd of the harbor freight kit, if that is the case it should be a 15W panel (or at least advertised as such), I assume it would be 15ish volts but don't have any first-hand exposure to this type of panel. If it were, those specs, he could charge the battery directly from the panel.

[bcroe]

Agreed. That panel looks like 1/3rd of the harbor freight kit, if that is the case it should be a 15W panel (or at least advertised as such), I assume it would be 15ish volts but don't have any first-hand exposure to this type of panel. If it were, those specs, he could charge the battery directly from the panel.

It does look like harbor freight, those setups were designed for 12 volt batteries. I would use at least
a diode between between the panel and the battery, so the battery can't be discharged by the panel at
night. I have some of those panels not in use. Bruce Roe