Mixing different voltage panels

[Kuna]

Is there any mistake in connecting a 12V panel (single panel) and a 6V panel in series to get 18 to charge a small 12V 3.49AH/20H battery?
Thanks for your kind replies.

[sensij]

Is there any mistake in connecting a 12V panel (single panel) and a 6V panel in series to get 18 to charge a small 12V 3.49AH/20H battery?
Thanks for your kind replies.

The voltage of panels in series will be additive, so they do not have to match. However, you should verify that the current produced by each panel is about the same.

I'm not sure why you would make an 18 V string to charge a 12 V battery. The "12 V" panel alone will actually operate at a higher voltage than that (typically around 18 V), appropriate for charging a 12 V battery.

[Kuna]

The voltage of panels in series will be additive, so they do not have to match. However, you should verify that the current produced by each panel is about the same.

I'm not sure why you would make an 18 V string to charge a 12 V battery. The "12 V" panel alone will actually operate at a higher voltage than that (typically around 18 V), appropriate for charging a 12 V battery.

Thanks Sensij,

I might have been misled or misunderstood by the theory of making a 36 cell panel to make 18V to charge a 12V battery.

Also my 12V panel shows around 12V not 17V or 18V.

[bcroe]

Thanks Sensij,

I might have been misled or misunderstood by the theory of making a 36 cell panel to make
18V to charge a 12V battery.

Also my 12V panel shows around 12V not 17V or 18V.

Unloaded, a 36 cell panel should show around 18V. It will decrease at current is drawn. Bruce Roe

[Kuna]

Unloaded, a 36 cell panel should show around 18V. It will decrease at current is drawn. Bruce Roe

Thanks again,

I understand with 36 cell panel. But right now I am stepping into sorlar and right now I have a 12V panel and a 6V panel trying to charge a 12V 3.49A/20H sealed battery.

Please read my first posting for the detail question.

Thanks for your time to help me.

[bcroe]

Thanks Sensij,

I might have been misled or misunderstood by the theory of making a 36 cell panel to make 18V to charge a 12V battery.

Also my 12V panel shows around 12V not 17V or 18V.

I am suggesting that if the 36 cell panel puts out 12V with NO LOAD (open circuit), it is defective.
Bruce Roe

[Kuna]

I am suggesting that if the 36 cell panel puts out 12V with NO LOAD (open circuit), it is defective.
Bruce Roe

Thanks Bruse,

I understand that you are trying to help me, but feeling that you did not pay attention to question fully or I have not explained it perfectly. I have a 12V Single cell and 6V single cell, but unfortunately you are writing about 36cell panel

http://www.aliexpress.com/item/Excellent-quality-12V-1-5W-Epoxy-Solar-Panels-Mini-Solar-Cells-Polycrystalline-Silicon-Solar-DIY-Solar/32421615949.html

http://www.aliexpress.com/item/6V-3W-495mA-Mini-monocrystalline-polycrystalline-solar-cell-battery-Panel-charger-for-mobile-phone-education-study/32272835717.html

my battery

http://www.digikey.ca/product-detail/en/LC-R123R4P/P172-ND/31530

I bought 12 batteries for only CDN$ 70.00 (For all 12pcs)

But I am trying to charge only one battery.

Hoping this will clear the confusion.

Thanks

[inetdog]

Thanks Bruse,

I understand that you are trying to help me, but feeling that you did not pay attention to question fully or I have not explained it perfectly. I have a 12V Single cell and 6V single cell, but unfortunately you are writing about 36cell panel

http://www.aliexpress.com/item/Excellent-quality-12V-1-5W-Epoxy-Solar-Panels-Mini-Solar-Cells-Polycrystalline-Silicon-Solar-DIY-Solar/32421615949.html

http://www.aliexpress.com/item/6V-3W-495mA-Mini-monocrystalline-polycrystalline-solar-cell-battery-Panel-charger-for-mobile-phone-education-study/32272835717.html

my battery

http://www.digikey.ca/product-detail/en/LC-R123R4P/P172-ND/31530

I bought 12 batteries for only CDN$ 70.00 (For all 12pcs)

But I am trying to charge only one battery.

Hoping this will clear the confusion.

Thanks

You have a single 12V panel, not a single cell. And a 6V single panel, not a single cell. A silicon based PV cell will have a voltage of about .5V. You put them in series to get higher voltages.
If instead of crystalline panels you have an amorphous thin film design you will not see the obvious boundaries between cells that you see with individual crystalline cells, but they are there just the same.
A panel that has a measured open circuit output of 12V is not what is normally called a 12V panel, and it is not a high enough voltage to charge a 12V lead acid battery.

Once again, you can put the two panels in series to use, with a charge controller (CC), to charge a 12V battery, but to get the best possible performance you need to match the current ratings of the two panels.
If the 12V and the 6V panels are roughly the same size then the 6V one will have twice the output current of the 12V one.
If the 12V panel is twice the size of the 6V panel, then they might work well in series, but it would be best to be able to compare the actual specifications to confirm that.

[PNjunction]

Kuna - the major problem we have is that you are playing with toys.

As such, the real question is do those "12v" panels you linked to really behave like normal large commercial panels, where in fact, the OCV or open circuit voltage is really anywhere from 17-22v with no load?

Or are they really toy panels, that when you put a multimeter on them, they do read only 12v max?

You are making it too hard for yourself by hunting out the bargain bin of Digikey for toys.

If you want to do it right, with only a 3.45A generic agm, they will accept only about .3C max current, (about 1.035A), and a REAL commercial "nominal 12v - which is really 17-22v ocv) panel, of only about 20 watts in size would do perfectly.

Of course you know that you ALSO need a charge controller right? Without it, you'll smoke your little agm's.

The biggest problem with playing with toy components is that you won't learn anything but how to nickel-and-dime your wallet empty.

[BironDowell]

As per my knowledge the voltage of panels in series will be additive, so they do not have to match. However, you should verify that the current produced by each panel is about the same.
Why you would make an 18 V string to charge a 12 V battery. The "12 V" panel alone will actually operate at a higher voltage than that (typically around 18 V), appropriate for charging a 12 V battery.

Sales links to PCB business not allowed for free, contact user JASON for ad rates.

[Zardiw]

Thanks again,

I understand with 36 cell panel. But right now I am stepping into sorlar and right now I have a 12V panel and a 6V panel trying to charge a 12V 3.49A/20H sealed battery.

Please read my first posting for the detail question.

Thanks for your time to help me.

Here's an idea.......why don't you try it and see what you get........you're not going to hurt anything......but make sure you don't overcharge your battery.....You may want to get a cheap charge controller.........to protect your battery from over charging.

Also.......the reason guys said that the current (amps) of each panel should be similar is because the amps from those 2 panels when connected in series.......will be the same amps that the lesser of the 2 panels is producing. i.e if one panel is putting out 5 amps and the other is putting out 12 amps.......you're only gonna get 5 amps out of the setup........at least that's what the common wisdom is.

Do you have a multi meter? Then you can check it all.

But the voltage will be 18V....approx.

z