What Size Mppt Controller Do I Need
MPPT Sizing Calculator
I am getting confused using both the online Sizing Calculator and Excel. I have four (4) panels with the following specifications.
325 Watts
Voc = 36
Vmpp = 30
Isc = eleven.88
Impp = 10.82
Can anyone help me determine which controller(due south) I need and in which configuration I demand to wire the panels? I have 430Ah of 12V AGM batteries to connect. Thank you.
So you take 375W x 4 = i.5KW worth of max. PV power.
Yous have a 12V battery bank. 1500W / 12V = 125A of accuse current at total PV ability.
A battery organisation Voltage of 12V brings some limitations which nosotros'll go into below.
The largest charge controller bachelor is a 100A one. The 150/100 would piece of work, but it will non harvest the full potential of your array considering its maximum charge power is 100A (1200W)
As your battery Voltage increases with accuse, y'all'll go 1480W of charge power, which is very close to your maximum PV output, but this will but happen shut to the superlative of the charge bike and when the battery is at the Absorb stage,
This is not ordinarily a problem, just a loss of potential PV ability.
Wire your panels with ii Series strings in parallel.
If you are really concerned about getting every final drop of PV energy then you'll need to consider two charger controllers. 2x 150/threescore will get you lot there with full power available after 12.5V which is realistic.
Wire these two controllers up with one series string each.
If you are fifty-fifty remotely thinking about expanding your PV power in the future, plan for this now and get bigger charge controllers if you can beget information technology.
When the PV Assortment size gets over well-nigh 1200W I always recommend that one take a look at increasing bombardment voltage to 24V, or preferably 48V. Especially when their are no DC loads in the system. Many advantages and very few disadvantages.
If you do have 12VDC loads, it is not a big deal to install a DC/DC converter to power those loads. At that place is some efficiency loss to take into consideration. Victron makes some. Below is the spec sail for a industrial course 60A converter that accepts 19-72VDC and outputs a pot adjustable eleven-15VDC. (I have mine ready at 13.2VDC.)
Pat
Thanks Pat. Unfortunately all the loads in my of-grid shed are already wired for 12V, including the inverter that runs power tools and a microwave. If I was to starting time again, I remember you lot're right - the college voltage organisation would be better.
What Size Mppt Controller Do I Need,
Source: https://community.victronenergy.com/questions/22167/mppt-sizing-calculator-1.html
Posted by: howardmenst1939.blogspot.com
It is not clear how many 12V batteries brand upwardly the total 430Ah chapters. If it is an even number of batteries (eastward.chiliad. two ten 215Ah), and then it may be ameliorate to connect these in serial, bold that is uniform with the residual of the system. This will halve the electric current then will be well within the range of a single MPPT.
Nigel, Thanks for your advice. I encounter now, the higher battery voltage would have been better. Unfortunately I have wired everything in my shed for 12V already. Live and larn, hey.
My current setup has 400W of panels, so this is my 'future upgrade'.
When looking at the sizing calculator, I had idea I'd wire up two 10 2 panels, which, according to the spec label, would get me 2 strings of 650W, with max voltage of 72V and max current of eleven.88A. With these numbers I thought two 75/15 controllers would be sufficient, but I now sympathize the current rating on the controller refers to the 12V battery side.
The panels will rarely receive full power all at in one case and the increment from 400W to ane,300W was planned to generously exceed any requirement I currently accept , so I'm not too concerned with a little clipping, but as you say, bigger is better.
Thanks.
Take care non to exceed the maximum voltage of the MPPT 75/xv. The MPPT will safely limit the maximum current only volition be damaged if the input voltage is exceeded.
The open-circuit voltage (Voc) of the panels is unremarkably specified at 25C and increases as the temperature drops - typically by 0.33% per degree Celsius. Two panels in series will therefore have a Voc of around 78V at 0 Celsius, which will about certainly impairment your MPPT.
Thanks Nigel. I'll await at 100V models. It could have been an expensive lesson if not for your advice.