Load 4 1.2 V Batteries with Solar Cells

[stefang7]

Hello,

I need a little help because the electric and me it's not two!

Here, I am finishing to mount a solar heating ( http://www.optik-solution.com/ , Fresnel heating v2).


My problem is the power part of a 12v pc fan, powered by small solar cells (see photo). And the fan is triggered by a bimetal switch 35 ° C / 50 ° C.



So I mounted the cells in threes in parallel and then connected the 4 parallel in series. The problem is that to start the fan I have to use a halogen over the cells to hope that the fan starts. So it won't work with a little overcast daylight. Of course the fan is connected directly to the cells and the switch is not mounted.



I already tried to put in series all the solar cells but it does not work either.

So as it does not work, I will use the method provided by the inventor and include 4 standard batteries of 1.2 v at 600 ma each.

Except that with the inventor's idea, there are only 4 small solar cells. I would like to keep all the solar cells (I don't know if I should connect them in series or in parallel). Now my question is what do I have to set up as a system which will charge my 4 batteries and which will cut the charge when these 4 small batteries are charged.
And the switch will be connected to the batteries to pump the energy needed for the fan.

Is there a simple kit?

Thank you for your answers

PS: I had taken photos, but I can't put them in this subject. I had to place them in my gallery.

[Alain G]

stefang7

Welcome to econology!

What voltage are your solar cells?

[stefang7]

Hello,

Thank you for your interest in my problem

Basically, the inventor asked for a solar solution based on garden bollards.

The thing is, I wanted to change this pattern. and use 8 solar cells delivering 1.5 V / 75 mA each and 6 low-end cells supplied with the garden terminals (I bought them as much to use them). For the latter I do not know the power of these solar cells.
All connected to a "system" which charges the 4 batteries (I actually used the wrong term ) and stop charging when necessary.

Then I connect the fan and the bimetal switch on the batteries.

here, if you need other info, don't hesitate to let me know

Thank you

[Alain G]

Hi stefang7!

You absolutely must put batteries so that your fan starts well.

You put 12 volts of batteries, and must at least have 14.5 volts on your fully charged batteries with the PV connected and in the sun, so put your PV in series to get this voltage without the engine running.
Repeat the tests and see if the batteries hold the charge, otherwise you will have to replace the fan for a less powerful one.

[stefang7]

yeah, i think i forgot to clarify something important.

I do not want the fan to run at full power.

Infact, in the manufacturer's instructions,

it turns this fan of 12 v and 0.33 A with 4 AA batteries of 1.2 v and 600 mA.

The inventor asked for a solar solution based on garden bollards.
Note that each battery individually had its own solar cell with its small printed circuit (if we say that).
I put an image in my image gallery of the manufacturer of this assembly diagram.

[Alain G]

stefang7

Make sure your fan starts well under 4,8 volts if not replaces the fan, you will put your PV for 5,5 or 6 volts at full load without the fan being connected.

[stefang7]

stefang7

Make sure your fan starts well under 4,8 volts if not replaces the fan, you will put your PV for 5,5 or 6 volts at full load without the fan being connected.

yes the fan starts with 4 AA batteries.

what does "PV" mean ??

[Alain G]

stefang7

Make sure your fan starts well under 4,8 volts if not replaces the fan, you will put your PV for 5,5 or 6 volts at full load without the fan being connected.

yes the fan starts with 4 AA batteries.

what does "PV" mean ??

Photovoltaic!

[stefang7]

OK...

will put the photovoltaic cells for 5,5 or 6 volts at full charge without the fan being connected

okay. but how do I do that? I don't understand "in charge"


sorry

[Alain G]

OK...

will put the photovoltaic cells for 5,5 or 6 volts at full charge without the fan being connected

okay. but how do I do that? I don't understand "in charge"


sorry

OK!
Make sure that your batteries are fully charged, if necessary use a mains charger, put your cells in series with a moderately strong light which is equivalent to a little cloud and you must obtain the voltage mentioned above.