Mppt 40A

Read your posting. You have answered your own question.

Lolz i guess I did but I have ppl telling me I can add 100 watt more and it wouldn't effect .should I add or no?
Thxz

Most solar panel installations will never produce the full nameplate wattage. So chances are you might get away adding that extra 100watt panel.

The good part about an MPPT CC is that usually the panels are wired in series to take advantage of the higher voltage going to it.

The problem comes when someday your panels in the cool early morning may send their full Voc voltage to the CC. Chances are you will then exceed the max DC voltage input to the CC which may damage it.

Think about that because it may not be worth the extra 100watts you may be able to harvest if you lose your CC.

Depending on a lot of factors like tilt angle and efficiencies the six panels if you buy one extra may never harvest up to 600w of power. but if you are not the risk taking type then you can just use four of the already existing panels

If you have 5 panels you really screwed yourself with a MPPT controller, and you do not even know it.

The whole point of using MPPT is to improve efficiency and save you a ton of money. You threw all that away using battery panels and wiring them all in parallel..

MPPT enables you to use much higher voltage and way less expensive Grid Tied Panels. Battery panels cost 2 to 6 times more GT panels $/watt. So you threw away a lot of money right there.

Lastly 5 is a PRIME NUMBER. That means you only have two option to configure your panels. Either all in parallel or all in series. Since this is a battery system using a MPPT Controller you can put 5 panels in series. That only leaves you with the worse option you could possible choose. ALL IN PARALLEL. Again pissing a lot of money away in a lot more wiring and larger wire.


You trapped yourself, live with what you have. You did about everything wrong you could have possible done. To add a 6th panel would require you to move up to 24 volt battery, and reconfigure your panels to 3 x 2.

If you have MPPT, why are you running a 12v system? I bet your panels are wired in parallel also.

When working with an MPPT CC there are two different design paths the manufacturer could have followed:

1. Make it like a PWM CC in that when the input circuit is conducting it will be carrying the full panel output current and power, and hoping that it will not overload the input devices, or
2. Make it reduce the power from the panels by limiting current and running at a voltage higher than Vmp so that only the amount of power needed for the output stage will be pulled from the panels and the input current will not be too much for the control elements.

Type 1 will list a maximum connected panel power which is not much higher than the rated output power.
Type 2 will list a maximum connected panel power which can be several times the rated output power or even "unlimited". (i.e. if you want to waste potential panel power, it is your decision.)

You need to know what type you have, or else simply trust the specification that the manufacturer has documented. It is better to allow for a higher array power rating than output power rating so that you can take advantage of the extra panel output (but still lower than nominal) at times before and after peak solar power each day. And allow for lower peak power in the winter.

So I should have a 24vot system better then a 12vot system? I want more power doing the night time .. I was thinking having a two 12volt battery and put them in parallel ...ppl telling me that the parallel system is better then 24volt system Are they right or ?
N on my mppt it shows from 15-20volt is that the max or no

P.s. Thank you

Am thinking of buying two new battery's 200A each should I buy two of 200A or should I get (12) 2volt or (4) 6volt battery to make it 12volt?? Help guys thank

Wiring batteries in parallel is not a good thing to do. It can lead to unequal charging and discharging due to even a small difference in resistance between the parallel wiring circuits.

It is always better to build a battery system using lower voltage batteries (2v, 4v & 6v) and wire them in series to create the desire system voltage.

Another thought is that higher the system voltage (> 12volts) the lower the amps being sent down each wire which allows you to use smaller wires and IMO run bigger loads.

Thank you suneagle am going to buy a 2 or 4 or 6volt battery... But let say I got six 6volt battery n I connect all of them. can I connect them and use them on 12volt system ? Mean put all of the 6volt into a 12volt battery ?

On the amp part as much as I can get

The only way to connect 6 x 6volt batteries to make a 12volt system would be to wire 3 set of 2 in parallel. That is not a good way to build a battery system based on what I said about unequal charging and discharging. When that happens one or more of the batteries can quickly fail and reduce the life of the entire system.

If you need a 12volt system then you can wire 2 x 6v xxxAh batteries. Or 3 x 4v XXXAh batteries, or 6 x 2V xxxAh batteries. The lower the voltage of each battery give you the option of finding high Ah rated ones.

How many watt hours do you plan to run each day and what is your 12volt Ah battery system size?

The one I have is 175Ah but I had it at least 2years that's y I want too buy a new one (2of them)

And I believe I use 3kw a day I think. I want at least 6hrs after 6pm. Until 12am that would be good

I ask u that ?about battery cuz I have 12volt power inver..and I really don't want to spend more money ...thinking of buying 1000watt power inver(12volt).for the night time to save power..

Today I put my plate in series to see if I can get more volt into my mppt (I add all my plate volt and it = 90.5)
I saw 20volt when I had my plate on parallel

My mppt says max.pv voltage is 100V can I add 1more (100watt) plate?
And my amp the hightest I saw it was 27 when I had pwm..(500watt plate)
But now I have mppt 40A I believe I can add 1more plate to make it at least 33A somewhere around there..
This is the confs. Part on the mppt it says 520W(12V) and I have 500watt now that what I don't get
Thanks

Well that 40A MPPT is rated for 520watt (12v) because when you divide 520w / 12v = 43A which is where the 40A rating comes from. Adding another 100 watt panel may be an issue (per earlier posts).

As for your 175Ah battery. That really can safely provide about 525watt hours daily so I feel you need a bigger battery system. The good part is that your solar pv and CC should be able to support a 350Ah battery system which could be 2 of those 175Ah batteries wired in parallel.

Your system's biggest negative is that you have a prime number of panels at 5. That limits your wiring options where 5 in series may overload that CC and 5 in parallel does not generated 40Amps of charging but will be about 5 times the Imp of one of those panels. Or my estimate of ~ 5 x 5.6A = 28amps. That is basically using about 67% of your total panel wattage.