Andrew Croft wrote: ↑In the absence of any other manufacturers data, I would assume 20 amps @ 12v on the load.back on this again
I bought the bloke at the fishery this solar charge controller (20A) https://www.amazon.co.uk/JZK-Intelligen ... B071ZZ2S84
works great, it charges his leasure battery no bother and the usb ports charge phones at 5v 2.5a. charged a nearly deed battery (125ah) back up to 'medium' on his battery tester. but ive been scratching my head trying to find out what the "load" terminals will pump out. I know it gives out 12v but ive not got a clue at what wattage or amperage so ive no idea what cree led light bar would be suitable as they go in to 75 watts for a decent one
the load terminals take power from the battery, not directly from the solar panel via the controller.
they look great for small use, but obvious chinese cheap so not ideal for big applications or more than 40v worth of panels, would be great for boats on the cheap.
also how many batteries do you think you could link up together to get a charge ? I think only one but the guy at the fishery thinks he could get away with a few. im not so sure though I think just one. especially with just that one solar panel it kicks out about 14-15v in direct sunlight, 12.5 in the shade.
As for lights, go for as small as you can get away with, a 75W light will pull 6.25 amps @ 12v.
Your 125 amp battery has a useable storage of 62.5 amps, assuming its in good knick, so 10 hours of use to use the storage.
BUT, if you want to do that regularly you have to have enough solar to replace the amps you use. The solar panel is the limiting factor. (See my earlier post)
You can rig as many batteries together as you like in parallel, which will keep the voltage at 12v. How long it will take to charge will be determined by the size of solar array, quality of the panel, integrity of the connection and the amount of solar energy from the sun. Angle and orientation of the panel will also effect.
The voltage of quality panel will stay relatively constant ( provided you don't throttle the flow of amps) when it is exposed to daylight, the amps will be the thing that changes with varying light.
Think of the battery as a water butt, the bigger the volume the longer to fill, the more sun (or more panels) the quick the fill time.
What is the Wp number on your solar panel and I can probably give you some better figures.