The Solar Power Expert Blog

Solar Pond Pump Kits

by Chris - January 5th, 2011.
Filed under: Solar Products. Tagged as: , , , , , , .

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In concert with solar powered fountains, there has been a huge proliferation of solar pond pumps and solar pond pump kits. If you are confused by the difference, solar powered fountains are complete, ready to go units. Solar pond pumps are used to replace traditional pumps used in ponds and other large water ornaments.

If you are looking for a solar pond pump to replace your existing pump, or simply to add a new water feature to your pond, then you’ll need to be sure that the solar pond pump, solar panel, and batteries are all properly sized to one another. There are many solar pond pumps kits on the market to simplify this process, but many of the cheaper kits include a very small pond pump which are often not properly sized.

Sizing the Solar Pond Pump

Start with the power rating of the solar pond pump. I’ll assume that you already have an idea of how many gallons per minute or per hour you need. For instance, a common low-budget solar pond pump is a 6 volt, 45 gallon per hour pump. These are used in birdbaths and small ornamental solar powered fountains. For a larger pond, you would probably want to go with an 18 volt, 200 gallon per hour solar pond pump.

Sizing the Solar Panel

Once you have the solar pond pump specified, you need to check and make sure the solar panel is properly sized. This is where unscrupulous manufacturers of solar pond pump kits will skimp. A solar panel’s rated voltage needs to meet or exceed the solar pond pumps rated voltage. Additionally, the power rating for the solar panel should be two to three times higher than the power rating of the solar pond pump.

For example, if your pump is rated at 2.5 watts, the solar panel should be rated at 5 to 7.5 watts. The reason for this is because the solar pond pump is rated at the power level that it takes to operate correctly. The power rating for the solar panel represent the maximum power output it will produce in full sunlight. These power ratings are quite different.

Sizing the Batteries

Batteries are not completely necessary for a solar pond pump. However, they will make your solar pond pump run much better. Another reason that you want the solar panel to be rated two to three times higher than the pump is because you’ll want the extra power to get stored into the batteries.

While not technically correct, a good rule of thumb for properly sizing the batteries is to multiply the batteries voltage and amp-hour (AH) capacity to determine how long they’ll run the solar pond pump. For example, if your solar pond pump is rated at 6 volts and 2.5 watts and the batteries that come with it form a 6 volt 1 amp-hour (or 1000 mAH) battery, then the batteries have:

6 (volts) * 1 (AH) = 6 (watt-hours)

This means they should run your solar pond pump for:
6 (watt-hours) / 2.5 (watts) = 2.4 (hours)

They won’t actually run it for this long, but this gives you a ‘theoretical’ maximum run time on the batteries.

As a final thought, be sure to read my comments on the warranty for solar powered fountains. The same concerns apply to solar pond pumps.

22 Responses to Solar Pond Pump Kits

  1. Nice one, there is actually some great points on this post some of my associates will find this worthwhile, will send them a link, thanks

  2. Fantastic blog! I really love how it is easy on my eyes as well as the facts are well written. I have bookmarked your site! Clean Energy is green energy. It will be interesting to see how the design of photovoltaic tile evolves over the next decade.

  3. Hello.This post was really fascinating, particularly since I was looking for thoughts on this subject last Saturday.

  4. Great information! I’ve been looking for something like this for a while now. Thanks!

  5. Most of the times i visit a blog I notice that most blogs are amateurish. Regarding your blog,I could honestly say that you writting is decent and your website solid.

  6. A guy I know told me to check out your blog. This is just the kind of substance I was searching for. I wish I’d have come across your site earlier.

  7. I do agree with all the ideas you have presented in your post. They are very convincing and will definitely work. Thanks for the post.

  8. Solar Pond Pump kit is really a one of the leading thing for the effective pond work. And this one really increase the power of our solar fountain. I really like the content of this post. Thanks for the sharing some regarding information.

  9. Mr. Troutner, thanks so much for putting in the time required to make a site like this… I found it while researching a way to make a solar-powered fountain… Fountain today, maybe house tomorrow 😉

    Don’t know if you can answer questions or not, but I’ll ask anyway:

    I bought a ready-made kit (DC pump, solar panel, battery) to make a very small fountain, and I’m suspecting the panel is not large enough to properly charge the battery *and* run the fountain during the day. To complicate matters, I also added to the length of cable running from the panel and the battery (so I could put the panel on the roof instead of on a stake pushed into the ground). I suspect the panel has a diode to control the charge, since there is no separate charge controller.

    My questions are: Does increasing the cable length decrease the charge actually getting to the battery? And, the original panel is rated at 8 watts, would 25 watt panel as a replacement work, or will that fry the battery?

    I can send the link to the kit if you want to try answering this…

    Trying solar in NC 😉

  10. Hey there NC,

    Good question! Thanks for asking!

    Yes, adding cable length will add resistance. It won’t stop your battery from charging, it just makes it charge slightly slower.

    Upgrading to a 25 watt panel would definitely help. However, potentially frying your batteries is a concern.

    You’ll want to ensure that the upgraded panel is rated to output the same voltage as the existing panel. Watts = Voltage X Current. You want your voltage to stay the same so that everything is compatible. This means any increase in wattage will result in extra current for charging the batteries and running the pump at the same time.

    Be sure to read my latest post on How to Build a Simple Solar System to figure out how to make sure the panel won’t fry your batteries. In a nutshell: You need to figure out what the 20-hour amp-hour rating of the batteries are. You’ll want to make sure that the maximum current going into the batteries does not exceed 1.5% of the amp-hour rating of the batteries.

    To put it mathematically:
    Max Solar Panel Current <= Pump Operating Current + 1.5% Batteries Amp-hour rating '<=' means less than or equal to Cheers! Chris Troutner

  11. Okay, I’m confused, which is not unusual for this visually-oriented graphic designer… but I try!

    I’m not sure I have the information needed to make the decision, can you help me with that? Below I’ll list all the info available to me about this kit:

    DC Pump:
    131 gallons per hour / 780 litters per hour
    Voltage range: 6-9V DC
    (couldn’t discern ampere info)

    Solar Panel:
    Rated power output: 8w
    Nominal voltage output: 18-20 volts
    Nominal current output: 444mA

    12v 2.6Ah/20hr
    Voltage Regulation:
    –standby: 13.4-13.8v
    –cyclic: 14.6-14.8v
    Initial Current: .78A max

    The cable between the panel and battery was originally 5m/16.4ft, I added 15ft to it, for a total of 31.4ft.

  12. Hey Gina,

    I thought your question deserved a detailed answer, so I wrote up a post here:



  13. Pond keepers always find helpful information online about fish pond pumps and for me using a solar powered pond pump instead of a wired one can save lot of money. It also makes it a lot easier to start a pond at home.

  14. Hi, I purchased a 3 tier fountain and I bought a seperate solar kit which is made by Jebao 3.5W with Battery storage and it didn’t work. Red light kept coming on. So what other pump would you recommend?

  15. Hey Becky,

    Great question! I started a forum thread based on your question. Check it out!

    Chris Troutner

  16. When you are looking for a perfect pond pump for your pond consider all of the different aspects of pond pump merchandise on the market today, select carefully, and you will be very pleased with the results. Features such as maximum heads, maximum output, head ratings, flow pumps, pressure pumps, standard voltage verses low voltage pond pumps, submersible verses external pond pumps, energy efficiency and much more should be considered.

  17. Mr. Toutner,
    I came upon your blog site as I was stressing over what pond pump I should buy having been warnned that solar pond pumps never really work like they should.
    I work at a day program site for the developmental disabled. I picked up a plastic pond at the roadside. We would like to equip it with a solar pump for enjoyment and education, but I’m green when it come to solar useage, and by that I mean ignorant. Would you help me? If I’m going to mount a panel on the roof, it would be about 22-25″ of cable to the pond. I’m not sure what flow rate would be best for this pond which propably holds about 100 gals. You guessed it, I’m also green when it comes to goldfish ponds.
    I’d be doing the installation at zero labor cost, but I’ve got to give the money people an idea what it’s going to cost them for the components. All I have at this point in time is the pond and a dream. I know our folks would greatly enjoy the water feature and fish, but the system has to work right, or I’ll feel bad. I can follow a schematic ok. I’m also ok with just being told what to buy.
    Help please!


  18. Hey Pat,

    Your first step is going to be to identify a proper pump. I’m not very knowledgable about sizing pumps to ponds, so you should check with a local landscaping or pond supply company. The one caveat for going solar is that you’ll want a DC pump, not an AC pump.

    If it was me, I’d probably go with a 12 volt, 360 GPH pump. I don’t know what the wattage or amp hour draw is for this pump, and knowing one of those is important. However, I doubt it draws more than 5 amps. A 60 watt solar panel should be adaquate for operating the pump in that case. Use 12 awg wire or smaller gauge (bigger wire).

    This setup will operate the pump directly. You don’t need a battery or any fancy electronics. However, the water will only pump when the sun shines, so keep that in mind. I hope that helps! If you want to use a different pump, write back with the voltage and either the wattage rating or the current draw. You’ll need to know those in order to size the rest of the system.



  19. Thanks Chris,
    That all sounds adequate. I’d like to have the battery component as well, but will see first what this intitial cost will be then consider it. If I stay under 5 amps, what might the battery back up system look like?

  20. A battery system will complicate things as you have to carefully balance the power input from the sun with the power output to the pump. You’ll need a charge controller to make the batteries and panels play nice and you’ll also need some form of low voltage disconnect to prevent deep discharge damage to the battery.

  21. Chris,
    I guess what we’ll be doing is powering a filter pump with AC; and running a fountain with the solar panel without battery and charge controller to keep it simple. This will be my first project, so simple sounds safe and doable.
    I’m getting the weekly instructional e-mails with the embedded links. I must say they are very helpful. Thanks! I’m sure as time goes on I’ll find all sorts of ways to use solar. Thanks for the inspiration!

  22. Hey Pat,

    I agree. Simple is best to start with. I think your plan is an excellent one and will achieve your desired result with a minimum of expense.

    I’m really glad I could help you out. I appreciate the feedback on the free solar education series I offer. I’m glad it’s helping you out. Feel free to post more comments if you have questions along the way.


    Chris Troutner

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