Water fountain pump

[ScottRanch]

Thanks Logan005, I totally agree with that. Unfortunately, there is no power to where I have this water fountain. So unless I have a power cord running over the lawn, or trench for iit, this is my only solution. If I were to trench, I would have to go a long way to the nearest grid source. And it's not a straight shot.

[Logan005]

I have a 100W panel connected to a deep cycle 12V battery, into a 20A charge controller. The pump says it's PMax 5W@12V. Will the panel be able to charge battery to keep the pump running 24x7 or will the battery go dead? I am new to solar energy. My first set up so I want to do it right. Thanks

I have done this as a personal knowledge experiment. great learning project. the problem is that little pump only uses a few dollars per year of grid energy, However a 110AH battery would have to be replaced every 5 years or so. about 100 dollars divided by 5 is 20 dollars per year. even if the pump cost 10 or 20 dollars of grid power per year to run, you would still be in the Neg. for any ROI
If grid power is avail, it does not make sense to use a battery.

[ScottRanch]

So then is the battery TO big for this pump? I can't believe I need 2 100W panels for a little fountain pump. Maybe I should get a battery with lower AH? But I still need to keep it running 24x7

[SunEagle]

Well that 105Ah battery is more than big enough to easily run the pump for 24 hours. But the problem is you will need about 10 amps of charging capability to keep that battery happy. Most FLA batteries require somewhere between 1/8 to 1/12 the Ah rating with 1/10 being the sweet spot. That would calculate out to 10.5amps which is more than a single 100 watt panel can output.

With only 5.62 amps you would be around 1/18 the Ah rating which is too slow. I would suggest getting a second 100 watt panel which that 20amp CC should be able to handle and now gets you more than 10.5 amps of charging capability.

As for the #14 wire. It may be too small to keep the voltage drop to less than 2%. The total distance could not exceed 3.7 feet. If the distance is about 10 feet you will need to go to a #10 AWG wire.

[ScottRanch]

The Imp is 5.62AH.The battery is a Duracell 12V deep cycle 105AH. My concern is if I am going to struggle with keeping the battery charged with the pump running 24x7. I think I can set the controller to 12hour and not 24. But I prefer to keep the pump running all the time to prevent stagnation of the water. I am using 14/2 wire between panel and controller and battery and controller.

[SunEagle]

Hello ScottRanch and welcome to Solar Panel Talk

That pump will use about 120 watt hours a day (5w x 24hr = 120wh). So you would need a 12v battery rated about 50Ah (120wh x 5 / 12v = 50Ah). If that 100watt panel has an Imp rating ~ 5 or more amps it should be able to recharge the battery but may have a problem if you do not get enough sunlight for a couple of days.

[ScottRanch]

I have a 100W panel connected to a deep cycle 12V battery, into a 20A charge controller. The pump says it's PMax 5W@12V. Will the panel be able to charge battery to keep the pump running 24x7 or will the battery go dead? I am new to solar energy. My first set up so I want to do it right. Thanks