Solar Panel Connections

[Felix]

Hello to all fellow aquapons,

    Im in the middle of the southwests desert with all the sunshine in the world, and am starting a series of container grow gardens out of a IBC containers, my city hast granted us $ to purchase the solar panel equipment needed. as of now we have a 45watt panel a charge controller and a 12v battery. The problem in my equation is that I wasn't sure how much voltage I would need to power the 500 gph submersible pump overnight without over heating or not having enough charge to last through the night. If anyone has any suggestions I would appreciate your input. 

[Steven Gardner]

First thing you need to know is how many watts your pump is. Then look into online solar calculators to see your areas min solar rating is. Doing the math with those two variables will give you the needed information to size your batteries amp hour rating.

Please keep in mind that at 10.2 a battery is at it's total depth of discharge. If you stay in the top 1 to 7 percent of the battery they will last a lot longer.

A common rule on off grid lighting would be to have 3 days of stand by power. Or purchase a charge controller with an low voltage shut down to protect your batteries.

[Alex Veidel]

Forsooth, I hast not a solution for thine dilemma. Harken unto those of which have rendered themselves more capable in the solar-arts. Dost though knowest of a supplier of the pumps that herein contain the appropriate sum that which total 12 volts? I await expectantly for some wondrous soothsayer to bring enlightenment unto mine understanding and thereby cast away mine affliction. Sorry... when I read the phrase "my city hast granted us", it made me smile :) And I apologize to all you Shakespeare enthusiasts as well...

Seriously though, does anyone know of a retailer that sells 12 volt pumps that are relatively inexpensive?