Backyard Aquaponics
A place to discuss aquaponics

I hate posting decisions like this.

It's like posting a picture of your lack of impulse control


http://www.ebay.com.au/itm/ws/eBayISAPI ... OC:AU:3160


But worse than that, it's like posting a picture of a flimsy bit of plastic that compares with the build quality of a disposable spork...

That I just spent 65$ on.

It's OK, the MPPT controller on my solar panel is a clone of that one as well, it also has "thunder protection" LOL

To answer your question, 20 amps is battery current, so you're very close to the limit. No more solar panels for you!

Cool, thanks.

How do you determine such stuff?

There doesn't seem to be rhyme nor reason*. Is it some kind of convention that says 20 amps refers to the output side of the equation?



*I never shop without thunder protection. That would be simply foolish

The panels are SR05-170, the open circuit voltage is 43.6v. I checked a couple and they produce that. The V at pmax is 35.8v and current at pmax is 4.76A though I have no way of testing that at the moment.
Lets just assume I don't have a lot of money and will only be able to buy one thing. I have the pump, I can easily get a small inverter, the battery is debatable. I am happy to only run daylight hours.
I am fairly good at modifying stuff.

Here are some options to consider:

The cheapest option may well be to try to find a 36v fountain pump...

The option most likely to work would be an mppt controller, a small (5aH) deep cycle battery and a 12v pump.

The option of a 100W dc-dc converter plus inverter plus existing pump would be my least favourite.

You may be able to get a 36v inverter on ebay but good luck with that.

The most geeky solution would be to rewire your panels for 12v and buy a 12v bilge pump.

Thanks for that nebbian, I will have a look round and see what I can find.

Hmm, came across some interesting products while ferreting around. There are apparently plug and play or SWEA grit tie inverters that use 1 or 2 panels so you just hook your panels up and plug into a house socket. This may be an option as I will be producing more than my pump uses.

Got a link sleepe?

Sent from my GT-P7100 using Tapatalk 2

ebay cheapy http://www.ebay.com.au/itm/350W-Grid-Ti ... 5895wt_988

Aus site http://www.laddertech.com.au/solar-prod ... w-inverter

The are not exactly going solar for backup but may be my cheapest easiest option.

I think that one requires AC to work, ie if you don't have mains power, it won't turn on. I could be wrong though.

nebbian, I can take an outage of a few weeks and the fish are ok, the GB biofilter will need support but that is doable, 4w is a breeze.

This plug in thing will be useful, and link them (maybe), when I eventually go bigger in that I can run it outside away from the trees and eventually find some batteries. Dumping load to the Grid seems sensible. The puzzling thing for me at the moment is the difference between "working volt vpm", this one is 36v ; and v at pmax which it says on mine is 35.8v.

Be very wary of those plug in grid inverters. I doubt they could produce any evidence they are certified for Australian use. For starters just the male plug unless it has some sort of protection to prevent it producing power until it has seen AC input.

Given the short term surge in power draw that pumps pull starting/stopping I think your best option is a solar regulator and battery.

Vmax is the optimum voltage for the solar panel were it will produce the most power under full sun.

If you connected a 36v panel for example direct to a 12v battery 2 things will happen. 1st the solar panel will try and raise the voltage above the batteries maximum and basically cook it.
But at the same time the panel volts will be held down by the battery and it will produce only about 65watts.
A PWM regulator will prevent the overcharging but the panels will still be operating at less than optimum voltage.


Working volt vpm is probably bad English for the same thing.


I've been running with a Morningstar TS-MPPT45 regulator and a Meanwell Ts-1000 on 500W of solar since August in a 48v dc configuration. I have about 400Ah of battery.
To prevent excessive charge/discharge of the batteries there is a 56v dc power supply adjusted to supply 52v connected as well.
At night etc that supplies power as soon as the batteries discharge to 52v.

Yeah for the cost of that i would look at a mppt tracker and a battery. If you have more than 1 panel available, then even better.

As usual I took no notice of what I was told (well a bit) .
I bought 2 plug and plays off ebay, these are to offset the pump and beer fridge, I will test one tomorrow ie switch everything off and see if the meter runs backwards. The other will have to be phased in as I don't want my energy provider to think my meter is defective.

I have aquired a 500w sine wave inverter 24v and 2 50ah gopher batteries, the inverter will keep the batteries charged when pulling ac then switch to the batteries to provide 240v when power goes down. (it was a swap).

I will have about 8 panels left so I am still debating my options.

Well the meter ran backwards
Now all I have to do is find somewhere to put it and do the wiring properly (and see how long it lasts).