Solarpanel and Batteries

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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Sun Oct 13, 2013 8:24 pm

Andrie: not sure why it didn't show up - I know the first 3 posts need approving -I did read it and approve it, so not sure what happened. Wow, I did not know the Arduino was 12v !? wonder why they chose that? hmm you can boost or buck to the voltage you need. dropping down is more efficient but either is possible. Doing two voltages gets messy though. I have a boost circuit that would give you the 9-12v from 5v. All my panels are low voltage (5v-6v) I have made paired panels for 12v and my folders are often configured to provide 5v and 12v but not at the same time.

I think the best I can offer is a usb /5v setup with a boost lead for the Arduino. This would have USB at one end and Arduino plug at the other. Is it 2.1mm? Other options are possible but this is probably the easiest I can make. Maybe this lead would be helpful for other Arduino users? I think it would be 5gbp or $8 for this lead but need to confirm.


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Re: Solarpanel and Batteries

Postby Andrie » Mon Oct 14, 2013 6:32 pm

Here is the Edit:
cottonpickers wrote:Andrie: not sure why it didn't show up - I know the first 3 posts need approving -I did read it and approve it, so not sure what happened.


I edited the message maybe you must re approve it.

cottonpickers wrote:Doing two voltages gets messy though. I have a boost circuit that would give you the 9-12v from 5v.


I would probably build more than one "Solar-Battery-Things" so I would not work with two voltages. If I may ask, can I please get a plan of your boost circuit.

cottonpickers wrote:All my panels are low voltage (5v-6v) I have made paired panels for 12v and my folders are often configured to provide 5v and 12v but not at the same time.


I must still get one or more of your Solar Panels. But I already have this Solar Panel: Here is photo number 1 and photo number 2, it came out of this set: Energizer Solar: Area Light and Solar Panel.

cottonpickers wrote:I think the best I can offer is a usb /5v setup with a boost lead for the Arduino. This would have USB at one end and Arduino plug at the other. Is it 2.1mm? Other options are possible but this is probably the easiest I can make. Maybe this lead would be helpful for other Arduino users? I think it would be 5gbp or $8 for this lead but need to confirm.


Yes it is 2.1mm and I think it would be helpful for the Arduino community and $8 sounds good.

What do you say about using Ni-Cd battery(ies) instead of NiMH battery(ies)? After I read this: Battery University What is the best type of battery, now I don't know what type of battery(ies) to use. :lol:

I found one of these (old) toy Meccano battery's.

Regards,
Andrie ;)
Last edited by Andrie on Wed Oct 16, 2013 1:42 pm, edited 8 times in total.

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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Mon Oct 14, 2013 9:03 pm

Ahh! you have a panel already ! - you should have said. I'm assuming this is nominal 12v ? in which case you should use this one, and the batteries you likely have already and convert down to 5v for the pi. What is the wattage rating or current? You could possibly simply connect it directly to 10 nimh (or 10 nicd) batteries to give you about 12v-14v. Provided the panel is around 200ma (2 watts) you could use it as it is. The simplest way to then get your 5v is to use a car usb adapter and connect it. If its more than 200ma you could be lazy and just cover the percentage of panel that will get you into that type of figure. You could then 'tweak' it a bit to give the current you want. Typically nimh are fine being charge at C/10 (capacity of the cell divided by 10) pretty much forever. If they are also used and get time off for good behaviour at night you can go a bit higher.

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Re: Solarpanel and Batteries

Postby Andrie » Wed Oct 16, 2013 7:15 am

Please look at the Edit: in my post above.

cottonpickers wrote:I'm assuming this is nominal 12v ?


I have not yet found any rating of the solar panel. Is there a way to test it with my multimeter?

cottonpickers wrote:in which case you should use this one,


I definitely would use this one.

cottonpickers wrote:and the batteries you likely have already and convert down to 5v for the pi.


No I have not yet done it.

cottonpickers wrote:What is the wattage rating or current?


Of the battery(ies) or the Solarpanel?

Regards,
Andrie

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Re: Solarpanel and Batteries

Postby cottonpickers » Wed Oct 16, 2013 7:29 pm

If you have a multimeter you can put black lead to COM and red lead to input (or the one that doesn't show 10A) and put the multimeter to voltage and touch the two leads on the panel. A 12v solar panel will read about 20v in sunlight. I'm pretty sure this will be 12 v

I meant panel wattage :)

If you then put the red lead into 10A socket and put the multimeter to amperage it should show the amps. More easy is to let me know the physical panel size and I can estimate it. This will tell me what you can charge

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Re: Solarpanel and Batteries

Postby Andrie » Thu Oct 17, 2013 9:29 am

cottonpickers wrote:If you have a multimeter you can put black lead to COM and red lead to input (or the one that doesn't show 10A) and put the multimeter to voltage and touch the two leads on the panel. A 12v solar panel will read about 20v in sunlight. I'm pretty sure this will be 12 v


My multimeter read 12 V in direct sunlight.

cottonpivkers wrote:If you then put the red lead into 10A socket and put the multimeter to amperage it should show the amps.


My multimeter read 0.20 A in direct sunlight.

cottonpickers wrote:More easy is to let me know the physical panel size and I can estimate it.


The physical size is 24 cm x 12 cm.

Regards Andrie. :)

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Re: Solarpanel and Batteries

Postby cottonpickers » Fri Oct 18, 2013 4:58 pm

If your multimeter reads 12v in sun, I guess this must be a 9v panel.... a little unusual but not a problem. 0.2amps indicates its about 2 watts. If I had that I think I would likely charge 8 nimh cells all together at once by charging in series. This would likely charge them quite nicely taking around 10 hours from flat to full. You could leave it plugged in forever and it wouldn't harm the cells as the current is so low near the full voltage.

I would get a cheap car USB charger and pull it apart or wire up so you have a permanent 12v supply and a permanent 5v / usb supply.
Does this make sense? if not shout and I can do a diagram or a pic for you.

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Re: Solarpanel and Batteries

Postby Andrie » Fri Oct 18, 2013 8:09 pm

Thanks, is there any other way to bring the 12 v down to 5 v (instead of using a usb power supply)?

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Re: Solarpanel and Batteries

Postby cottonpickers » Fri Oct 18, 2013 8:48 pm

Ah.. maybe you misunderstand. I mean get one of these:



And wire it in permanently.

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Re: Solarpanel and Batteries

Postby Andrie » Mon Oct 21, 2013 2:14 pm

Sorry, but I am a person that like adventure: is there any other way to bring the 12 v down to 5 v (instead of using a car/sigar usb power supply)? :lol:

Regards,
Andrie ;)


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