Definitely outdoors but it may be a bit nerdy. I have questions for someone versed in electronic things.

I have this pump for recirculating water in a small yard bird pond and it came with this solar panel. It works well in sunlight or even a little on cloudy, bright days. I want to add a 12v, 9 ah battery for cloudy day backup, not for 24/7 operation.

Amps=Watts/Volts is the formula I have found for computing the draw of the pump. This equates to a .42 amp draw by this pump. Am I off-base with this? I have also been told I should use a charge controller to regulate the battery charge and discharge which makes sense. I have several I've been looking at. I would like to hear from those in the know about such things. Thanks for any insight.

A couple of controllers I'm considering are the Renogy Voyager 20 A and the LNEX 20A .

You'll need a charge controller if adding the battery.

Im a fan of running more panels in parallel rather than adding a battery. Not sure if your pump can handle that without also needing a controller.

Thanks for the reply. The pump and solar panel were bundled by the store on Amazon so I'm attempting to keep that part there. The battery backup they supply is junk, however. Any opinion/knowledge on the 2 controllers listed?

Very nice design of water feature, I am going to shamelessly copy you!

txrancher69 said:

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Very nice design of water feature, I am going to shamelessly copy you!

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Thanks. I started with a basic idea and it morphed. No shame. I will give you this tip, build larger than you think you want.

Beware to not burn up your pump running it hard. I've found that I can double the life of my solar diaphragm pumps downhole by running at 50% duty cycle and daylight only.

This pump just sits in water but I get your point. I am considering a timer as well.

I use Renogy stuff for both my truck and trailer's solar builds. It's been reliable and easy to setup. I used a different controller, but that doesn't mean yours is bad.

I am not sure I have been thinking about this correctly or explaining what I want to achieve. This pump works well for my application which is a small bird pond/bath with a small waterfall, a "leaking" old hand pump, and a fountain at the opposite end from the waterfall. Photos earlier in the thread. The pump furnishes the correct amount of water to each of these when running at full power. This system supplier also has a battery backup that I returned for a couple of reasons. It is a 14.8V/2600mAh Backup lithium battery. It supposedly stored power for cloudy days but only for a 4-6 hour run.

I hoped to achieve having a battery on standby to use on these cloudy days when there isn't enough brightness to power the pump. It will operate on overcast days that are bright. After further digging, I'm thinking I can't do this with the equipment we have been discussing. I believe if I use a charge controller, the pump will be constantly drawing from the battery instead of running straight solar on sunny days. For this reason, I see why it would be important to be able to fully charge the battery with the controller/solar panel combination. For those that understand this technology, is this correct? If so, I'm looking to go the wrong way.

Yes, but also no. You seem to have the correct equipment.

Your solar panel is sized so it can produce enough power to charge the battery and power the pump.

Nice work. I keep toying with the idea of making something similar myself.

Appreciate it. I have found out a bit more info on this also. Will go the CC route soon.

MouthBQ98 said:

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Nice work. I keep toying with the idea of making something similar myself.

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Thanks, appreciated.