Hi all,
Some one sent me a private message. There seems to be confusion about what I recommend--so here is a clarification.
Here is what I believe.
For systems under 500 watts it is hard to beat the Grape 40 amp controller.
For larger systems MPPT makes a great deal of sense, and is cheaper per watt.
12 volt panels:
https://www.solarblvd.com/product-category/solar-panels-systems/12-volt-solar-panels/
24 volt panels:
https://www.solarblvd.com/product-category/solar-panels-systems/24-volt-solar-panels/
My system was purchased when panel cost per watt was $5.50 so going MPPT was a no brainer. My input voltage is 33 vdc and charging started at 5:45 a.m. on May 10. It is now 8:20 and charging is 7.5 amps. Load is 2.5 amps so 5 amps @ 14.3 volts are going to the battery bank.
A 1650 watt system with the PT-100 Magnum controller parts cost would be about $1300. In a nominal 12 volt system just the panels would cost that much, then there would be the complication of having 3 grape controllers, and LARGE wire.
My advice in a nutshell? Once you know the size of system, find the cheapest cost per watt to do so. Below 500 watts the Grape controller is darn hard to beat. Above 1000 watts MPPT is cheaper.
