If you put the 3 panels in series you may not outperform pwm during low sun angles. Look at the efficiency curves in the manual. At low solar output the controller efficiency is not very good. Efficiency is better when panels are in parallel.
I don't understand why you want to pursue a series configuration. The 150V max rating is not to be taken lightly. 150V is the switching FET breakdown voltage. You never even want to get close to that limit.
At 25C the panel has an open circuit voltage of 45.5V. Voc temperature coefficient is -0.159V/C. At 19F, or -7.2C the open circuit voltage is:
Voc = 45.5V + (0.159 * (25C + 7.2C)) = 50.62V
3 panels will bring you 1.86V over the 150V absolute max limit.
Do what you want, but no respectable engineer will sign off on that. 19F isn't even that cold. You don't have to be camping. The trailer could be parked somewhere.
carl2591 wrote:
My main purpose of this post was not to find the cheapest way to do this install. I want to do the best with a budget in mind and using the most cost effective products of quality, like morningstar products.
I know there are other good lower cost products but when you read post of folks that do a lot of solar like my friend handy bob solar, you learn what is a good quality product at a good price and will do the best job for your batteries.
In reading the morningstar white paper on the difference between MPPT PWM on lower watts and voltage system the PWM is the best choice. On higher voltage systems the MPPT will out perform more often with lower sun angles.
