Small Solar System

Robin · 01-29-12, 12:29 AM

Hello.
I am looking for some advice.
I need to know the size/type etc of solar panel, rechargeable battery, controller (and any accessories) to run an RFID reader (specification attached) on solar power. I would need the equipment to have ‘over capacity’ to allow for attachments to the reader if required (like GPRS units).
The reader would be ‘on’ 24 hours, and may need to work both night and day (reading RFID tags).

The reader is 500mA and uses 9-12V

Thank you for your help.

Xringer · 01-29-12, 10:22 AM

I'm going to assume the location (Dubai?) gets a lot of sun.?.
And there isn't going to be any structures that will cast shadows on the PV panels?

Anyways, a 12V charge controller normally applies more than 12V to the battery.
So, you need to know if your RFID reader can be used with at least 15VDC.

Xantrex and Morning Star Charge Controllers are very reliable.

Any brand-name 12v compatible solar PV panel should be okay, something like a BP Solar BP 490J.
Depending on the amount of sun and add-on power use, I would think about using an 80w to 200w panel.
Larger is almost always better.

The Surrette Sealed-AGM Batteries are good, but their cost is high.
If this is a short term system, you might want to buy cheaper
Marine-RV Lead-Acid battery and just replace it when needed..
It could last 5 or 6 years, depending on care (adding water) and conditions.
Extreme weather takes a toll on batteries..

At night, your RDIF might need 10 to 15 amp hours of charge in the battery.
If you want to be covered for a few days, without sun..
The storage needs to be up around 100 amp hours.
So, maybe a 250 AH battery bank might be enough.?.

There is a forum where there are a lot of experts in off-grid systems..
Solar Electric Power Discussion Forum by Northern Arizona Wind & Sun
That's where I go with my questions..

Robin · 01-30-12, 06:55 AM

Xringer, Thanks for your advice.
Would a 12V controller not 'control' the voltage going to the appliance (RFID Reader) to 12V only?

Xringer · 01-30-12, 08:59 AM

A solar PV charge controller reduces the higher voltage from the PV panel down to a safe level for charging the battery.
Right now, my 48v battery bank is fully changed to 59 volts. So each (12v) battery is at 14.75 volts.

See Switch Bank settings on page 13.
http://www.morningstarcorp.com/en/su...nual.04.EN.pdf

Since your RFID Reader can run on 9vdc, you could just buy a small 12vdc to 9vdc regulator..
From Ebay.. eBay - New & used electronics

01-29-12, 12:29 AM	#1
Robin Lurking Renovator Join Date: Jan 2012 Location: Dubai Posts: 2 Thanks: 1 Thanked 0 Times in 0 Posts	Small Solar System Hello. I am looking for some advice. I need to know the size/type etc of solar panel, rechargeable battery, controller (and any accessories) to run an RFID reader (specification attached) on solar power. I would need the equipment to have ‘over capacity’ to allow for attachments to the reader if required (like GPRS units). The reader would be ‘on’ 24 hours, and may need to work both night and day (reading RFID tags). The reader is 500mA and uses 9-12V Thank you for your help.

01-29-12, 10:22 AM	#2
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I'm going to assume the location (Dubai?) gets a lot of sun.?. And there isn't going to be any structures that will cast shadows on the PV panels? Anyways, a 12V charge controller normally applies more than 12V to the battery. So, you need to know if your RFID reader can be used with at least 15VDC. Xantrex and Morning Star Charge Controllers are very reliable. Any brand-name 12v compatible solar PV panel should be okay, something like a BP Solar BP 490J. Depending on the amount of sun and add-on power use, I would think about using an 80w to 200w panel. Larger is almost always better. The Surrette Sealed-AGM Batteries are good, but their cost is high. If this is a short term system, you might want to buy cheaper Marine-RV Lead-Acid battery and just replace it when needed.. It could last 5 or 6 years, depending on care (adding water) and conditions. Extreme weather takes a toll on batteries.. At night, your RDIF might need 10 to 15 amp hours of charge in the battery. If you want to be covered for a few days, without sun.. The storage needs to be up around 100 amp hours. So, maybe a 250 AH battery bank might be enough.?. There is a forum where there are a lot of experts in off-grid systems.. Solar Electric Power Discussion Forum by Northern Arizona Wind & Sun That's where I go with my questions.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

01-30-12, 08:59 AM	#4
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	A solar PV charge controller reduces the higher voltage from the PV panel down to a safe level for charging the battery. Right now, my 48v battery bank is fully changed to 59 volts. So each (12v) battery is at 14.75 volts. See Switch Bank settings on page 13. http://www.morningstarcorp.com/en/su...nual.04.EN.pdf Since your RFID Reader can run on 9vdc, you could just buy a small 12vdc to 9vdc regulator.. From Ebay.. eBay - New & used electronics __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

01-30-12, 06:55 AM	#3
Robin Lurking Renovator Join Date: Jan 2012 Location: Dubai Posts: 2 Thanks: 1 Thanked 0 Times in 0 Posts	Xringer, Thanks for your advice. Would a 12V controller not 'control' the voltage going to the appliance (RFID Reader) to 12V only?