Denns

I would personally max out the array if funds and space allow. Just cap the charge rate of the battery in the inverter settings. Its always better in my book to get it done right the first time. It will incur cost later on to add more panels and reconfigure the array. Otherwise just max out the one array and leave the other empty. If he wants to upgrade later on and cant find the same panels then they would need to move the other set to the one input and then get panels for the other side. You also get better cloud generation the more panels you can add so I see little benefit to limiting the array for the sake of the battery when it can be taken care off with a single setting. Having more panels also means the inverter will pull from the panels and not the battery even when loads exceed 5kW which is a plus.

It does tell you the main info you need. The PV range is 125 to 425 Vdc. That's the most important parameter and what you base your array around. Can I ask what additional information you want? I assume it has 2 MPPT inputs since it says 2x5500W PV. Current is the last thing I check if ever. If you happen to go over the current limit it just clips and at 22A that will be never unless you parallel your strings.

Feb is a bit too early. I went in June and it was bloody cold at night. During the day you can be in shirts and shorts.

Winter evenings in Zim gets very cold. It’s just the day that is warm in winter.

Interesting @Scorp007. I’ve never seen a cable with copper coating and Al internals. Seems like a lot of work to sell a cable cheaper. This article has some good information on tinned copper if interested. https://www.crutchfield.com/S-JaPyDhdZ0JB/learn/what-is-tinned-copper-wire.html

I suspect it’s tinned copper. Not Aluminium. It looks like copper on the inside of each strand as in the picture but is a bit silver on the outside. tinned copper has much much better properties than a purely copper only cable. The main benefit being less susceptible to corrosion.

Yes, I got 19.6mm2. That’s why I said it looks to be a 19 or 20mm2 cable. Leaning more on 19.

5mm is diameter I assume? Thats about 19/20 mm2. It’s more than fine for your battery. I have 35mm2 on mine but that’s because I have a 500ah bank but I only pull 125A max from it via DC breaker. I wanted a more future proof thing to not have to upgrade later again.

All my panels are south facing and I’m offgrid so I wouldn’t say it’s a waste. You get poor generation in winter true, but my array still generates about 30% more than I need in winter for the house. Most of my generation occurs after 10am. Summer I generate almost 3 to 4 times mores than I need. Having south facing panels on an install can help considerably to meet energy needs as not everyone has a north facing roof. I have a freely unshaded north facing roof and another south roof that will be used when energy requirements go up such as getting an EV. I can basically increase PV to about 20kWp. But to get back to his problem, he needs to check summer values. I get 1/3 of my peak in Winter. There may actually be nothing wrong with his install. I would focus less on the peak and more on what the kWh generation is for the whole day. You can have a peak of 5kW and generate more than someone with a peak of 10.

Lol, sorry about that🤣. The problem with adding more batteries is that you are using more than the panels can provide. So you will still just drain them if the powercuts are a bit longer. 300/400W from your bank means about 10 hours of run time. Your solar you said peaks at 700W on a good day. That doesnt leave much for the batteries. Thats why i recommended a generator. An MPPT inverter would be better. And you may get closer to 1000W but you still need to keep an eye on your loads.

Best value for money generator which wont give issues with the inverter accepting the charge is this one below. Thats what I could find.

No, you dont have to do anything on the panels side. You said you cant put panels anywhere else so you are limited there. 24V is already low enough by the way. You wont get anymore out of the batteries so leave it there please. It will just damage them running them further down to 20V. You basically have 2 choices, limit usage when power cuts occur to make the batteries last longer. Or buy another 1 or 2 batteries which becomes expensive. Personally, I would just buy a generator. The cheapest 4 stroke you can buy. Run it for 2/3 hours to charge up the batteries to full. You can do that around 3pm to top up the batteries with whatever the solar couldnt finish charging up. No noise at night. And because you have solar, the generator just acts as a top up and not the sole source of charging. You can get a cheap 4 stroke for about 4k. Try and get at least a 2.5kVA and only run it around 60% of its load. You would need to set the input of the inverter to APL to accept the generator also. They can be a bit finicky with Generator sources but can be made to work. Also connect a load to the generator before connecting to the inverter. Thats another trick to get it the inverter to accept the charge.

Sorry I think you misunderstood me. PWM likes current vs an MPPT that likes Voltage. So for PWM, Parallel panels are best actually, not series. He actually has "too much" voltage from those panels even though he is in parallel. The best configuration for him would be panels with a voltage no more than 32V or so but a lot of current. So perfect scenario for him assuming such panels existed would be 2x800W panels, each with a Vmp of 32V and Imp of 25A each. Both in parallel to keep the voltage at 32 and the current would be 50A. But alas such panels dont exist. So the next best thing would be to get 400/450W panels with the Vp of 32V and current of about 13 to 15A. Wire all 3 in parallel. 2 400W panels with such specs would get you the same results as 2x585W panels like he has. In his case though small or big panels would make no difference as he can only do 2 panels unfortunately. PWM brings the panel voltage down to the battery voltage.Whatever excess voltage it sees from the panels goes to waste basically.

My experience with PWM controllers kind of shows otherwise to be honest. His panels seem to have a Vmp of 42V. The PwM will only make use of 30V from that panel so it really will only pull a maximum of 400W from that panel. The installer didn’t match the panels to the type of charge controller he has so at best he will get 2/3 from that panel. Had he gotten panels that had a Vmp of around 32/33 then most of that panel would have been used. So he can comfortably add another 1 or 2 panels and then he will start seeing numbers close to that PWM limit. Later on he can change the arrangement of the panels when he switches to MPPT. I had a PWM once and made the same mistake of buying large panels without matching the voltage to them. I had 4 on mine and did eventually hit the 1600W my controller could do which made things much better for generation. I was still wasting a lot of solar potential as the panels had a Vmp of 42. PWM isn’t necessary bad, it’s just that installers don’t match the panels to the inverter. I sold my PWM to a friend and specced the panels for it. He gets to about 90% of the panel rating all because the Panels have a Vmp of 32 if I recall. So decently efficient.

He is limited by space it seems. He could have added a 3rd panel to that inverter but he is now limited by the space. Sounds like his inverter is set to cut off too low. And he also needs to manage expectations. If running a large TV and a few other things those batteries just wont last at night.