I plan to install 10 - 395W panels as a 5 Series x 2 Parallel configuration for a 48V system. From computing the MPPT charge controller, the Excel VE-MPPT has 2 options: #1. SmartSolar 250/100 and #2. the MPPT RS 450/100.
Base on the comparison below, I did not see much advantage of the MPPT RS 450/100 controller vs. the SmartSolar 250/100, except for being able to connect more panels in series to 450V. Did I miss something for the MPPT RS purpose? Why would one use the MPPTR RS?
Comparison:
| Category | #1 SmartSolar | #2 MPPT RS | notes |
| Price | $950 | $1295 | |
| Size | Small | Large | |
| Battery | 12, 14, 36, 48 | 48 | |
| Efficiency @48V | .99 | .96 | |
| Power @48V | 5800 | 5760 |
|
| Voc Min | +5V | 120V | #2 - 120V is way too high for shadowing days |
| Vmpp min | +1V | 80 | |
| Voc Max | 250 | 450 | |
| Max PV voltage @ min Temp (-10C) | 241.7 | 241.7 | #2 has more head room |
| Min PV Voltage @ max Temp (70C) | 157.8V | 158.4V | |
| Max current @MPP min Temp | 88.7A | 87.3A | #2 MPPT RS tracker current is 18A |
| Max current @MPP max Temp | 71.8A | 70.7A | |
| PV Array | 5S x 2P | 5S x 1 - per Track (2) | #2 has room to grow 3 more panels |
