Solar Panel System Troubleshooting - Charging Battery

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
153 replies · 18K views
Since your existing solar system has excess capacity, you could connect the pump to that as just an additional load. You may or may not need a way to keep the pump off at night. If the lights stay on long enough, just let the pump run. It is unclear if the lights are on continuously. If not, then replace whatever switches them with a device to select between lights and pump.

As an alternative, you might consider this pump. It has half the water flow but about 1/3 the power requirement. (Smaller panel and battery needed... or longer runtime.)
https://www.amazon.com/dp/B00JWJIC0K/?tag=pfamazon01-20

Wolst73 said:
Is there a controller without a delay?
No idea, I've never done a solar-electric system. Anyone out there, is there available a solar controller without a switching delay?

Wolst73 said:
how would you wire it so that pump is running directly off panel when there is enough sunlight and switch to battery when it's power output drops? (Jim's schematic pictures would be great!)
The instructions that come with the controller would show that... (or I suppose you could ask @jim hardy to do your research.)
 
Engineering news on Phys.org
Wolst73 said:
how would you wire it so that pump is running directly off panel when there is enough sunlight and switch to battery when it's power output drops? (Jim's schematic pictures would be great!)

Simplest answer is : Just parallel them. Strongest source, battery or panel, carries the load. But you probably want the low voltage cutout feature of a controller so as to not run the battery flat?

You'd have to let us read the controller's instruction manual. Probably you'll see it in there first, though. Is it linked earlier in the thread?
 
Sorry for being lazy about research. Have in my mind how I want it to work but don't know where to look to see if it will work or what devices are out there to make it work.

Tom.G said:
As an alternative, you might consider this pump.
I saw that pump but was worried the 400mA might be to low and fry the motor.

jim hardy said:
You'd have to let us read the controller's instruction manual.

IMG_0016.JPG
IMG_0014.JPG
IMG_0017.JPG


This might help. Hopefully you can enlarge and read. I have it set on 3. Lights on for 3 hrs but there is still a delay even though it says it should be off. 17 has the load on continuous when there is sunshine. Where does power for load come from in this case? Panel charges battery, battery powers load? When sun goes down, load shuts off and battery won't be totally drained? This is a cheap controller so may not be smart enough to alternate as @anorlunda stated. This would work although would be nice to run for the 3 hrs that the lights are on.