Spec a Panel for my Fountain

[LarryJ]

Hello. I'm a complete novice when it comes to solar and electricity. I can change a light fixture, but leave it to the pros beyond that.
Wondering if someone could spec out a panel for my home fountain/birdbath project. I have a 12v water pump that uses 3.8 amps. I just want to know how large a panel I'll need to run the pump when the sun is out. It doesn't need to run at night. I plan on connecting the panel directly to the pump, no battery in between, unless that will cause a problem. I have a spare 12v battery that I could use if necessary, don't know how to configure to shut it off at night.
I'm more interested in getting this project installed and operational than I am about learning solar theory and configuring the electrical, if you know what I mean. Thanks.

[Mike90250]

I would locate a 12V panel (which will output 18V) that can supply twice the amps your pump needs, so look for a 8A panel.

You are going to have a voltage mismatch with the 18v panel and your 12v pump. So you might look into a voltage regulator to protect the pump from overvoltage

[LarryJ]

I would locate a 12V panel (which will output 18V) that can supply twice the amps your pump needs, so look for a 8A panel.

You are going to have a voltage mismatch with the 18v panel and your 12v pump. So you might look into a voltage regulator to protect the pump from overvoltage

Thanks for the reply. Before seeing your post I ordered a 100w, 12v panel. I don't need the pump to run at full power.
Don't know what 8A means. 8 amps?

[Mike90250]

8A = 8 amps Common electrical shorthand. V = volts R=resistance ga= wire gauge

[LarryJ]

8A = 8 amps Common electrical shorthand. V = volts R=resistance ga= wire gauge

Wait. I'm confused. The pump is 3.8amps. Why do I need 8A. The one I ordered produces 5.5 amps. Will that work?

[Mike90250]

the panel puts out 5.5 amps under laboratory conditions. In real life, 80% is about right. Any cloud cover oor have and it drops right off and the pump will start, 8A gives you a better chance it will run more. But now try the 5.5 since that's whats coming

[LarryJ]

the panel puts out 5.5 amps under laboratory conditions. In real life, 80% is about right. Any cloud cover oor have and it drops right off and the pump will start, 8A gives you a better chance it will run more. But now try the 5.5 since that's whats coming

What type of connectors are these. They're on the GrapeSolar panel.
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[peakbagger]

FWIW I have a solar pumping project with a bilge pump rated for around 3 amps.The pump runs with a 20 year old 55 watt panel in full sun. The panel has definitely lost capacity over the years.I had a spare so I put one in parallel. Note the pump will draw what it needs to draw depending where on the pump curve its being asked to run on. My installation has high discharge pressure to make it up into my storage tank. Its running lots of psi and not a lot of GPM so my amp draw is lower than lots of flow and little discharge pressure. My guess is 100 watts is plenty.