640 W HPBC solar panel with 144 cells. Voc 54.02 V · Isc 14.98 A · TcVoc -0.2%/°C.
Select the panel you want to replace
Voc
54.02 V
Vmpp
44.67 V
Isc
14.98 A
Impp
14.33 A
TcVoc
-0.2 %/°C
TcPmax
-0.26 %/°C
Pmax
640 W
Cells
144
Bifaciality
70%
The LONGi LR7-72HVDF-640M is a 640 W solar panel. Finding a compatible replacement requires matching the original electrical characteristics — particularly Voc, Vmpp, Isc, and temperature coefficients — to ensure safe operation within the same string.
Use the form above to find panels that match these specifications. Then verify the replacement in the String Compatibility Calculator with your inverter.
| Model | Power | Voc | Isc |
|---|---|---|---|
| LR7-72HVDF-645M | 645 W | 54.12 V | 15.06 A |
| LR7-72HVDF-650M | 650 W | 54.22 V | 15.14 A |
| LR7-72HVDF-655M | 655 W | 54.32 V | 15.22 A |
| LR7-72HVDF-660M | 660 W | 54.42 V | 15.3 A |
| LR7-72HVDF-665M | 665 W | 54.52 V | 15.38 A |
| LR7-72HVDF-670M | 670 W | 54.62 V | 15.46 A |
The most critical specs to match are: cell count (must be exactly 144), Voc close to 54.02 V (within ±5%), and temperature coefficient TcVoc close to -0.2%/°C. If Voc differs significantly, the string voltage at extreme temperatures may shift outside the inverter's MPPT range. The replacement finder above pre-screens all candidates by these criteria.
A higher wattage panel usually has a higher Vmpp or Isc, which can affect string voltage and current. Small increases (up to 10–15%) are typically safe if the other electrical specs align. The replacement finder shows a compatibility score — 'Exact match' means the specs align closely. Always verify the replacement in the String Compatibility Calculator with your inverter before installation.
If the replacement has a significantly different Voc or Vmpp, the string voltage may shift outside the inverter's MPPT range, reducing energy production or causing faults. This effect is amplified at temperature extremes: at low temperatures, voltage rises by the TcVoc coefficient. The replacement finder automatically accounts for this — it scores candidates by how closely the electrical specs match the original LONGi LR7-72HVDF-640M.