diy solar

diy solar

Beginner planning solar pond aeration

Progress! (all solar components have arrived, and confirmed to be functional) But... below is my first dumb assembly question:
1689625887780.png

... the Giandel 300W inverter I purchased comes with a car converter cable - but no battery clamps. Is there a simple way to make this work with my setup?

Or should I just replace it with a slightly beefier inverter with "standard" DC inputs and battery cables (such as Giandel 600W for $113) ?
 
While I've got you here... I haven't ordered any mounting components yet.

I'm planning to just do ground mounting temporarily, while I confirm that the location and setup as a whole works Ok.

Thoughts on this Eco-Worthy option as a low-cost, tiltable ground mount? (Topsolar themselves doesn't seem to have a mount that will work for my panel kit)


(eventually I intend to replace this with a pole-mounted setup, using brackets such as this from Renogy - but need to find one to accommodate my larger panels - and more importantly, the time to get this setup installed..)
 
rddmddiysp said:
the Giandel 300W inverter I purchased comes with a car converter cable - but no battery clamps. Is there a simple way to make this work with my setup?
Click to expand...

You've got 2 options.

1:Super Simple but Untrustworthy: Buy a car lighter socket from any auto parts store and wire it to the battery. Works OK for testing but not a very water resistant or clean connection and definitely wouldn't do it long term..

2:The Better Way: On car lighters the center pin is Pos+ so mark the wires, cut off the car plug, crimp on ring terminals, bolt to battery. Much cleaner connection, less points of failure, and no excess heat from the socket connection.

As for the mounts, I have 1 of those Eco-Worthy kits and it's pretty flimsy. There are lots of easy ways to mount panels, especially if you don't want them tilt able, using plain old lumber or if you're handy with a welder old bed frames from Craigslist are usually free. Even if you're really wanting tilt able, that's pretty easy to do as well. Grab some popcorn and peruse Youtube for ground mount panels and see what different people have done. I've used everything from lumber and deck boards to PVC pipe to steel to make mounts and it's just a matter of being a little creative with what you've got available.
 
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Warpspeed said:
Why not just use a 12v dc air pump and run it direct from a bunch of 12v solar panels ?
Something like this perhaps:
Click to expand...
The pump he's already got is about 30% more airflow and larger tubing to get out into a deeper pond.

As for running things from a "12v" panel, it really depends on the specs and tolerances of the pump. A "12v" panel can produce upwards of 22+ volts and the amperage will fluctuate wildly as clouds go by and the like. If the pump ever stops the sun has to hit enough to produce enough amperage from the panels to overcome the LRA or startup current for the pump. Having the battery and controller solves a LOT of problems.

When you see things like "12v Panel" and "24v Panel" what that really is saying is that "I can produce enough voltage to charge a 12v nominal system, but not enough for 24v or 48v" and "I can produce enough voltage to charge a 24v or 12v nominal system, but not 48v". It's a marketing term.
 
I know of a swimming pool filter pump belt driven by a treadmill motor direct from a bunch of series connected solar panels and it works very well indeed. It just speeds up and slows down depending on solar conditions. Just direct connection, no controls of any kind.

I cannot see why an air pump cannot speed up and slow down, it does not need to run at constant speed.
There will never be full locked rotor amps, power will gradually ramp up, and the motor will start turning slowly long before anything like full load rated current is ever reached.

The panel will only reach 22v+ if it is completely unloaded.
Provided there is always sufficient load the voltage can never reach that high.
Its just a case of balancing the power available with the load, and a bit of experimentation should easily get a working system.
 
I've seen too many people try to run pumps right off the panels and yes, it can be done sometimes, I've seen 80% of those systems fail in the first week because the pump worked REALLY WELL and then died. Experimentation is expensive and the OP wanted the simplest system that would use the parts he already had to get it working.

Granted, the experimenting can be WAY more fun! ?
 
Simplest system ?
Solar controller.
Battery.
Inverter.
Some system to prevent over discharging the battery.
All of that does not come cheap, and there is far more to potentially go wrong.

Experimentation is expensive ?
Golly, a solar panel and a pump and maybe a multimeter.

If you want reliability, its just a case of NOT OVERPOWERING the pump.

Sure some sophistication would make it work a lot better, but is all the extra cost worth it ?
Maybe three pumps and three solar panels will blow a lot more bubbles for the same cost than one pump and a whole lot of fancy electronics.
 
Thank you @Rednecktek and @Warpspeed for the replies.

My next dumb question relates to the charge controller..

The controller that came with the Topsolar kit did not include a manual - and I've been unable to find one for this specific version online. Is there a reliable way to determine which battery types the settings refer to (b1, b2, b3, 1b1, 1b2, 1b3, 2b1, 2b2, 2b3) - and, more pressingly, whether the controller supports LiFePO4 batteries at all?

(Keeping in mind that I'm very new to all of this...) If LiFePO4 batteries aren't "officially" supported, do I need to purchase a new controller that does? Or could I just set the battery type to the closest / most similar battery type and be Ok?
 
Now that I think about it more... I wouldn't mind spending a bit more money on a better charge controller - especially one that reports the power that's being produced by the panels (maybe I shouldn't be surprised, given how cheap this one is, but I don't see that information anywhere..)

Could y'all save me some research, and recommend a modest cost (say, less than $100) controller that supports LiFePO4 and would provide this information?

edit: Sorry, ignore that request - I just remembered that @Rednecktek had previously listed a few options here. I will probably go with "Tried and Trued with a few features" for $90, if I'm not convinced the existing cheap-o controller is Ok to use..
 
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@rddmddisp, there is quite a lot to think about here.
Are you planning on a completely dc, or a 110v ac system ?
Are you planning on fitting a battery ?

​

 
@efficientPV - I'm only planning to run this system during the warm months, so fortunately that's one consideration I don't need to think about (for now)...

@Warpspeed - yes, I'm pretty far along in the planning / purchasing at this point - doing an AC system, with battery and inverter.
 
Update:

The system has been installed and running successfully for three weeks now! Thanks again for everyone's input. Additional info & questions below..

Screen Shot 2023-09-10 at 22.10.38.png

Screen Shot 2023-09-10 at 22.12.11.png

PV -> SCC -> lifepo4 battery -> inverter -> wall timer -> pump

I haven't configured the SCC yet for the lifepo4 battery, because it requires "advanced" settings (no pre-configured option). I should get on this.

My current dilemma:
I've been experimenting with the wall timer in terms of number of hours and times of day that the pump is enabled. On hot & sunny days I've easily gotten 12 hours without draining the battery below 80%; on some rainy days I've either scaled it back to 3-4 hours, or accidentally drained the battery.

The SCC has a bluetooth listener, but is not connected to wifi or 5g - so in order to get readings on battery charge level and charging status, I need to be within ~100 feet. I've been checking a couple times per day (and adjusting the timer settings up or down accordingly) - but won't be willing to continue this indefinitely.

Twice, the battery has been drained to the point where the inverter shuts off. This stops the wall timer (obviously), which necessitates resetting both that and the inverter. Since I have the equipment locked up in the bin, it's a modest hassle.

At one point I recall being cautioned against connecting an inverter directly to the DC load ports of the SCC - because the load pulled by the inverter would be likely to overload the controller - which is why I have it connected this way instead. But I'm very foggy on those details..

Now I'm really wishing I could connect the inverter to the controller, to better monitor & control disconnect - well before the battery gets close to 0% (although from what I understand that's not very damaging for a lifepo4, as compared with other battery types (?))

The details:
  • Charge controller is an HQST 20A
  • Giandel 12V DC inverter with No Load Current of 0.8A and Output Power of 600W (surge 1200W).
  • Pump is 120 VAC; 1.3A; 51 Watts

Can you advise on whether it's safe / advisable to connect the inverter directly to the SCC in this arrangement?

Thank you!
 
You can try it and hope the startup surge on the pump doesn't go over 240w which is going to be the limit on those output terminals on the SCC. As small as your pump is I don't see it being an issue but keep an eye on it for a couple days. To be saver put a 15a inline fuse there to pop before the SCC overloads, but it should just alarm the SCC if it tried to draw too much. You'd have to log in and reset that.

In short, with a 50w load your 20a SCC terminals should be plenty.
 
What you could do, is turn the inverter on and off according to battery voltage.
Inverter only starts when there is sufficient voltage, and turns off when the battery falls to some preset level.

I purchased a battery charger controller from e-bay a few months ago.
https://www.ebay.com.au/itm/383761867417?var=652138606585

What this is designed to do is turn on a battery charger when the battery falls below some minimum set voltage, and turn off the charger when the battery reaches a higher set voltage.
The relay has ten amp changeover contacts, so it could also be used to control a load instead of a charger.

You could still use a time clock, in conjunction with one of the above controllers. That would prevent the battery from being over discharged on gloomy days.
 
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That's actually not a bad idea. Get yourself a relay and connect the Load leads to it to turn on and off the inverter at set voltages! For $20 it protects your SCC and can switch the loads on and off with plenty of power overhead.

Another good idea would be to replace those battery clamps with a ring terminal so you get cleaner connection.
 
After a bit more thought, I would hook it all up as follows:
Connect the solar controller permanently to the battery.

Connect the inverter to the battery via the timer, (which will have decent electrical contacts). The solar controller will not see the start up surge, because the battery will supply that. So inverter always runs between preset times and charges the internal battery inside the timer.

Connect the inverter ac output directly to the timer ac input, and to the pump via the relay on the battery under/over voltage controller.

That could be programmed to turn on the pump at a fairly "medium" type of battery voltage, say anything over 13v or something, so it will pretty much always start up when the timer commands a start.

If the battery runs out of grunt, it disconnects the pump load, leaving the inverter running without any load except the timer.
Inverter no load idling current is low enough to run with a fairly low battery if you choose an appropriate minimum pump drop out voltage.
The timer then switches off the inverter at the usual set time, leaving the timer internal battery fully recharged.

That should always start the pump, but it may not run for the full set time if the battery starts to get low.
 
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The other option being:

Leave the system as-is mostly,
Run the AC from the timer out to the relay, then to the pump,
Connect the Load ports to the AC outlet, set low voltage cutoff to 11.5, restore at 13v.

The battery will still feed the inverter and keep the timer on time, but if it's too low the AC won't get from the timer to the pump, so there's no real load other than the little bit of standby power of the inverter and the timer. When the sun finally comes out and the battery starts getting filled up it'll close the contactor and turn the pump back on. At that point the panels should be able to run the pump and still charge up the battery through the day.

You might need to tweak the settings for the load port as you see how it runs, but this ought to get you on paper.
 
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