Solarpanel and Batteries

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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Mon Oct 21, 2013 6:19 pm

Lol well I picked that as it's cheap and can be dismantled. And works fine. If you want to build up rather than tear down yo can get a lm3940 (I can post you one with the capacitors for £1 plus postage) that will take most voltages and output regulated 5v , or if you want to go somewhere in between any ''5v buck' converter off ebay should do the trick.


Andrie
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Re: Solarpanel and Batteries

Postby Andrie » Sat Nov 02, 2013 9:49 am

cottonpickers wrote:If you want to build up rather than tear down yo can get a lm3940 (I can post you one with the capacitors for £1 plus postage) that will take most voltages and output regulated 5v


£1 = (+-)12 South African Rands + (+-)R10 (importing costs) = R22. So I would probably get them somewhere for cheaper is SA.

cottonpickers wrote:or if you want to go somewhere in between any ''5v buck' converter off ebay should do the trick.


I would like to buy something without paying importing costs.

What about using this battery??

Kind Regards,
Andrie

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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Sun Nov 03, 2013 11:02 am

Andrie: I can't access that link unfortunately. There are lots of ways to get 5v from the panel - hopefully that part or similar are available locally.

Andrie
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Re: Solarpanel and Batteries

Postby Andrie » Mon Nov 04, 2013 8:45 am


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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Wed Nov 06, 2013 7:22 am

Andrie : yes that battery would be oish with your panel. You need to make sure that the voltage isn't above 7.2v. As it Risks overcharging and damaging it. I think you'd still need to drop a little current for the pi as it will often be 6.8v when full. One cheap way is a diode / rectifier. These are very cheap or salvageable from old electronics. A standard diode will drop about 0.7 volts

RawLiquid
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Re: Solarpanel and Batteries

Postby RawLiquid » Sun Apr 27, 2014 12:54 am

Hi I just happened across this site because I'm currently setting up a solar setup for a Pi,
Initially I intended to shut it down each night as the panel stopped producing, but after doing the math I'm debating on bumping the battery from a 12V 7Ah up to a 10 or 12Ah and instead monitor for a low voltage condition to trigger the shutdown, My issue then becomes how to make sure that once it shuts itself down, once the sun is back up it turns back on...If power is never actually drops enough, the Pi will just stay asleep since the next day the battery will charge up fully, then with the reduced power usage it will never drop low enough to reset it....

I wanted to correct something though looking at the date stamps of this thread, it is highly likely 1) you have already figured this out, or 2) are no longer interested in this...
The Arduino's are NOT 12V devices. they are mostly designed to run off 5v or 3.3v depending on the clock speed and model. The power regulator on the uno, etc is a 5v regulator, and can handle between 7 and 12 volts...
You can power it through the USB connector using 5v, or you can send 5v straight to the 5v pin to power it. HOWEVER it is recommended that you use some form of regulator to keep from damaging the board, since running to the 5v pin bypasses the onboard regulator and power protections...

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cottonpickers
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Re: Solarpanel and Batteries

Postby cottonpickers » Sun Apr 27, 2014 6:54 pm

Rawliquid: I did not know that about the arduino. The solution I found to the issue of starting back up in the morning with enough juice to switch it on is with my 5v 7 day timer ( viewtopic.php?f=4&t=493 ) this allows you to keep some juice in your batteries overnight so that in the morning you can happily automatically switch it on at a preset time. You do need to have a shutdown script that is ahead of the timer pulling the juice. Using one of the li-ion power boxes likely is regulated enough to keep the arduino happy. Thanks for the info btw. !

RawLiquid
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Re: Solarpanel and Batteries

Postby RawLiquid » Tue Apr 29, 2014 6:19 am

My two biggest issues at the moment are actually how to best preserve the battery, and how to prevent the whole thing from melting down.
My installation point is out in the high desert, sunshine isn't so much a problem as using the solar info from a site I came across, it says the insolation there even in december is around 2.6, nearly 8 in June. So would you have any suggestions on a battery that won't be damaged just by being in an enclosed box at potentially triple digit temps outside, hopefully not an oven inside?

RawLiquid
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Re: Solarpanel and Batteries

Postby RawLiquid » Tue Apr 29, 2014 7:42 am

I just realized that I was looking for an answer to something I didn't ask...
Am I missing something, or given a 10w panel, and a 12v sla in theory should be able to run 24/7 (excluding weather issues) and by bumping the battery up to a 10Ah or better 12Ah, that should likely cover it unless there is rain for a couple days straight, in which case my low voltage trigger will shut it down as the voltage drops, then hopefully once the rain is gone it will start itself back up...I would opt for your timer, but unfortunately unless you managed to get it to me in about 18 hours, I will already be on my way to do a presentation and install....and it's about a 2.5 hour drive to get back out there for any modifications...

benz83
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Re: Solarpanel and Batteries

Postby benz83 » Tue Jul 01, 2014 9:42 pm

hi guys i wrote a post ...not compare. However i wanna ask if a solar charger with battery built in is ok with raspberry?


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