I have 2 x JA Solar 600 panels in Series facing East + 2 x JA Solar 600 panels in Series facing West. I have the East series and West Series coming into 1 x Victron 145/45 MPPT in Parallel. In morning the East Series Panels likely generate max power but West Series is half; In afternoon West Series will generate Max but East Series half. At say mid-day East will generate 75% power and West 75% power. If East and West are coming into the MPPT 145/45 in Parallel will that confuse the MPPT or will it just deal with the different voltage from East and West of the two Series ok ?
It will try and find the maximum power point of the combined panels and for example this may well be say 75% east and 0% west when the absolute peak could be say 75% east and 30% west if they had their own MPPT. With east west 2 controllers will give best performance.
Thanks. Would putting them into Series work to one MPPT. So if East in morning was putting out max say 45v and West 5v - in Series Voltage is then 50v. At Midday East 35v + West 35V = 70v and afetrnoon: East 5v + West 45v = 50v. Would the MPPT then be happier OR do the panels mess it all up? If East was first at 45v but then into West at 5v do the second panels drop the total to 5v?
In series it is about current capacity, if one side generates less current than the other it limits the current and bypass diodes (which should be in the panels) let the other sides current through so again you get all one not the other.
I would get a second MPPT. But then again all my panels are fused and connected to Phoenix Contact SPD’s. Next to the (here) mandatory frame grounding. Not to mention that I don’t like blocking diodes.
Ok thanks - darn it - so there is no work around in Parallel the MPPT works on the lowest common denominator Voltage and in Series the Panels work at the lowest common denominator Amperage. No win here. Looks like I need to buy another MPPT - thanks for all the advice - Last thing please - I will thus have 3 x MPPT going to BusBar + Battery + Multiplus II
Is my wiring diagram with 3 x MPPT’s and Battery and Multiplus all connecting to the BusBar correct?
Diagram looks right, the fise to the inverter looks to small, that will fliw only 2.5kW. Recommended value will be in the manual.
Much appreciated
So, as it turns out I have blown 2 x MPPT’s - as shown on the design - I had assumed an MPPT would step up from 43v to the 48v required by the Battery … OH BOY was that an incorrect and costly assumption
But you showed them in series on the drawing so they should have been producing 90 to 100V for a 48V battery, which needs up to nearly 60V to charge, which was correct for the set up when I looked at it. I assume you tried them in parallel. MPPTs do not boost voltage, only regulate down.
I suggest you check the Victron MPPT calculator, that will confirm your set up.
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