Question on wiring two small solar panels in Parallel

[WartHog]

I'm making a solar-powered Hummingbird bath/fountain and want to wire two small solar panels in Parallel, if possible. Purpose is so that one can be angled to catch the morning sun and the other to catch the afternoon sun to keep the pump running most of the day.

Below are pics of the kits that I'm working with - specs for the panels are 7V, 1.5W. I'm assuming that the power cable is just two conductors but I haven't opened it because it will likely void the warranty so wanted to as my questions before doing so.

[SkyHawk]

Wiring them in parallel is not a problem. Since you don't plan to have both angled into the sun at the same time you probably wont have to worry about the max input capacity of the solar charge controller (if you plan to use one) or the pump motor if they are wired directly to it.

The cable you show might be a coax type cable rather than two clean strands. There might be a center core and an outer conductor weave or foil. You can't know until you cut.

Never the less you can still work with that co-ax type if you want to cut them up and solder them together, but you might also consider just making a parallel harness that they can plug into.

I'd probably Yolo it and cut / solder them up onto a single plug.

I don't know if solar panels in parallel can steal power from one another if one is shaded and one is not, I have never tested that. If so you may need a diode or two (but the panels may already have such a diode or similar circuit)

[WartHog]

Wiring them in parallel is not a problem. Since you don't plan to have both angled into the sun at the same time you probably wont have to worry about the max input capacity of the solar charge controller (if you plan to use one).

The cable you show might be a coax type cable rather than two clean strands. There might be a center core and an outer conductor weave. You can't know until you cut.

Never the less you can still work with that co-ax type if you want to cut them up and solder them together, but you might also consider just making a parallel harness that they can plug into.

I'd probably Yolo it and cut / solder them up onto a single plug.

Yeah, I tried to get info from the ebay Seller on the cable/connector plugs but no dice. There are no Electronic Parts Suppliers around my area anymore that I could take the plugs to identify them.

[SkyHawk]

They look like standard barrel plugs, probably 2.1 mm, but I see they are weather tight and that exact style may not be easy to find.

So I say chop-chop!

[Marauder2003]

Perhaps these could help? Don?t know your barrel size.

https://www.amazon.com/USHANLIN-Adapter-Splitter-Security-Cameras/dp/B07DY7QJ47

[WartHog]

Marauder - I took a digital caliper and measured the outside of the metar barrel and got 5.46mm. Eyeballing the center conductor, it looks like 2mm to me so maybe that 5.5mm x 2.1mm splitter might work.

SkyHawk - I know nothing about Solar - what is a Charge Controller and why might I need one? Will probably have the two panels mounted at roughly a 60 degree angle to each other so when the sun is directly overhead, both panels would be producing power.

[SkyHawk]

Marauder - I took a digital caliper and measured the outside of the metar barrel and got 5.46mm. Eyeballing the center conductor, it looks like 2mm to me so maybe that 5.5mm x 2.1mm splitter might work.

SkyHawk - I know nothing about Solar - what is a Charge Controller and why might I need one? Will probably have the two panels mounted at roughly a 60 degree angle to each other so when the sun is directly overhead, both panels would be producing power.

If you are not going to have a battery in this system then you don't need a charge controller.

That splitter would probably work - and if it does you could seal the connections with adhesive lined heat shrink tubing to give you some weather resistance

[WartHog]

Thanks for the knowledge/edjumacation

[WartHog]

One last question - running the two panels in Parallel is going to double the amperage to three amps. This won't have any detrimental effect on the cheap little Chinese water pump, right?

[SkyHawk]

One last question - running the two panels in Parallel is going to double the amperage to three amps. This won't have any detrimental effect on the cheap little Chinese water pump, right?

It will not double the drawn amps. It could double the circuit amp capacity, but it is the load (the pump in this case) that determines the actual amp draw.

Also, there will be no doubling of anything unless the panels are pointed in the exact same direction and angle. And if you did point the panels the same, only the capacity for amp draw goes up but the actual amp draw would only increase if you added another pump.

[WartHog]

Splitter works fine - going to have to play around with panel angles, experiment using painters masking tape to cut efficiency as output out of pump was double that of one panel.

[SkyHawk]

Splitter works fine - going to have to play around with panel angles, experiment using painters masking tape to cut efficiency as output out of pump was double that of one panel.

That is interesting. It seems your motor can take more power than a single panel can give, that is why it is outputting more. I hadn't considered your panel was acting like a choke.

You could try a battery and charge controller in the circuit and the battery would act like a buffer (because it has a fixed voltage out) and the controller would shunt any extra input when the battery was fully charged.

You could also try a regulated / adjustable output buck/boost type converter inline before the motor.

But a far cheaper solution may be what you are on to - just mask the panels with something that can hold up to the weather. Play around with tape and cardboard at first and if it produces the results you want, then you can swap the cardboard out for something else that will last. You need to make sure that a single masked panel can still run the pump, because when the sun is at lower angles a single panel producing may be all you get

[WartHog]

I'll use some aluminized HVAC ducting tape as the blocker as it has a very sticky adhesive. Haven't caught one Hummer taking a bath yet even though we're hitting 95-100 in this current heat wave. They're sure sucking down the juice at the feeder which sits a couple of feet away.

[brassburnz]

Probably cheaper to buy two pumps.

I had one. It got pretty nasty after a few weeks. Birds ignored it. Gave it away.

[the86d]

If it got nasty, could you use a couple large filters like Berky tower filters or well sediment intake filter, or something, and maybe add a small amount of bleach, or empty and spray down with 10% bleach once every few weeks, if willing to put all that work in?

...Or a bucket in-line working as a sediment/solid gravity filter like all the people harvesting water in free states do from creeks for bird droppings, maybe it'll work to decrease some of the algae?