Bus Crazy
Join Date: Jun 2016
Location: Orange County, CA
Posts: 1,362
Year: 1990
Coachwork: Crown, integral. (With 2kW of tiltable solar)
Chassis: Crown Supercoach II (rear engine)
Engine: Detroit 6V92TAC, DDEC 2, Jake brake, Allison HT740
Rated Cap: 37,400 lbs GVWR
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Those are good CCs, like all Victron products are. However, I think you're planning it wrong. Any MPPT controller will be most efficient when down-converting about twice the battery charge voltage from the panels, i.e. if it takes in about 30 volts to produce 14.7 for the batteries - efficiencies will be typically in the high-90s percent at that step-down ratio. If you're asking it to down-convert from 96 volts it will produce much more heat, and heat shortens the life of electronics more than almost anything else. And most "12 volt" panels typically produce about 18 volts Vmp if they have 36 cells - 144 volts (eight times 18 volts) is more than most single CCs can reliably handle, and an edge-of-cloud event can briefly push that voltage even higher than that.
Also, I'm guessing you had planned to have all your panels in series. That's a good idea for home installations to reduce cable losses where there could be a considerable distance from array to CC, but any mobile installation won't have to deal with such long cable runs. If one panel on a series-connected array is shaded, even slightly such as by leaves or obstructions on the roof, the entire array's output can be cut to nothing (especially if the panels have only series-wired cells). A parallel-wired array on the other hand will still produce usable power even if one panel is shaded.
If you split your array into two you can have a CC for each half, then you won't run into issues of too much power per CC, and you'll have redundancy to prevent complete system failure if one critical component fails. For example, I have eight grid-tie panels and two 60 amp Morningstar CCs: each CC charges its own bank of four batteries, then both banks are combined to power the DC loads. This way, I will always have at least half my power even if something bad happens. Having two CCs also means that if you tilt your panels to face the sun better, if one array is tilted at a different angle than the other and therefore producing slightly different power, then a single CC won't get confused trying to calculate the PV's maximum power point.
John
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