water garden tank/skimmer charging unit question.

[herbhero1977]

Hi all

I’m sure this is a silly question but I’m more of a gardener than an electrical guru so I thought I’d turn to the experts. The wife has a birthday coming up and she’s got her heart set on a water garden for the backyard, fish, plants the whole nine yards. So a friend of mine gave me this large solar panels last summer and I’ve not had much use for them given my lack of electrical know-how. But they got me thinking that perhaps I could make the pond a bit more self sustainable by running the tank and skimmer with solar power. Trouble comes when night falls or a less than sunny day. This got me to wondering how I could go about setting it up so that the system runs multiple batteries. What I mean to say is there a way I can set it up so that one battery is charged by the panel, while the other runs the tank and skimmer, then when the working battery dips below a certain value the connections switch and the charging battery runs the skimmer and tank and the working battery begins to charge? Ideally I’d like to achieve this as simple and inexpensive as possible and wasn’t sure if some electrical manufacturer makes such a thing.

Thanks

 

[3v0]

I have been water gardening for about 30 years.
It takes a lot of current to pump water.
My suggestion is to use the solar with a battery to provide aireation. That way if the power fails you will still have some water movement in the pond.

 

[4pyros]

You can charge batterys its done all the time. Do you have any specs on the panels?

 

[herbhero1977]

40 Watts
17.30 Volts
2.31 amps

 

[4pyros]

OK you mite be good for 2 amps for 7 hours or 14 Amp Hours.
How much power will your "tank and skimmer" need?

 

[alec_t]

Even a small skimmer needs 40W or so, so the PV panels may/may not be quite enough.

 

[herbhero1977]

So you're suggesting a can't set it up to alternate charging and powering with two batteries?

 

[alec_t]

It depends on the expected duty cycle of the skimmer/aerator.
Provided the skimmer/aerator isn't expected to run for prolonged periods (i.e. more or less continuously) then yes, it's doable. The battery charge time will have to average more than the average discharge time, allowing for inevitable inefficiencies in the system.

 

[4pyros]

Your alternate charging scheme is not as good as you would think. There are losses involved in charging batteries. Many heat. You would be better off running the skimmer/aerator directly from the panel when you can, than charging another battery at that time.