I am planning having two Wattstunde EXF 160 unit placed on each side of the boat - 1 each side on pulpit. I expect the sun input can be quit different on the two. Is it better to have one MPPT for each and conncet to the 24VDC battery bank, or can I connect them both to one MPPT unit and have same good output?
Which is the amps calculated from eg. 160W/24VDC =6,8 Amps or by the Isc (short circuit current) of the panels
Thank you
Seems like a high cost for 320W of power. Do you have a spot for a single ~320W panel?
Hi Thanks
Yes that is true I also wanted to have higher output. I struggle to have an Targa at the back of the boat, as my radarpole and windvane is there as well. I cannot find any good panels which can be on the bimini with-out a more rigid construction to support the panels - so I went for thepulpits on the back of the boat - each side. I could try to find other panels that are larger in Watt - but they also become wider = stick out or down when in harbour. I how-ever agree it is a lot of money for 320 W. I do how-ever need 24 VDC. If you have any good suggest for these I appriciate any input
Normally for panels (or panel arrays) with different orientations you need separate MPPT chargers.
There is an exception: for a house with East and West facing roof, you can make one East array (one or more panels in series) and one identical West array and then connect the the two arrays in parallel and put them on the same MPPT. But this won't work on a boat.
"Which is the amps calculated from eg. 160W/24VDC =6,8 Amps or by the Isc (short circuit current) of the panels"
Amps into the battery? Or Amps into the charger?
For Amps into the battery, with a MPPT charger, maximum current into the battery would be about (peak Array power)/(Battery voltage).
There are some loses.
For Amps into the MPPT charger, maximum current would be ISC x (number of panels or strings of panels in parallel).
When choosing the MPPT charger, you need to know VOC of your panel array (or VOC of the panel if a single panel) and lowest recorded temperature in your area. This voltage (corrected for the lowest temperature) must be under (lower than) the MPPT maximum allowed VOC voltage. So leave some safety margin.
Also, the panel/array voltage must be at least 5V higher than the maximum battery voltage. But aim for more than that.
