645 W TOPCon solar panel with 66 cells. Voc 49.62 V · Isc 16.46 A · TcVoc -0.2%/°C.
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5 panels found · 3705 panels excluded
640 W
TOPCon| Parameter | Original | Replacement | Deviation |
|---|---|---|---|
| Voc | 49.62 V | 49.52 V | 0.2% |
| Vmpp | 40.88 V | 40.78 V | 0.2% |
| Isc | 16.46 A | 16.38 A | 0.5% |
| Impp | 15.78 A | 15.69 A | 0.6% |
| TcVoc | -0.2 %/°C | -0.2 %/°C | ±0.000 %/°C |
| TcPmax | -0.26 %/°C | -0.26 %/°C | ±0.000 %/°C |
650 W
TOPCon| Parameter | Original | Replacement | Deviation |
|---|---|---|---|
| Voc | 49.62 V | 49.72 V | 0.2% |
| Vmpp | 40.88 V | 40.98 V | 0.2% |
| Isc | 16.46 A | 16.54 A | 0.5% |
| Impp | 15.78 A | 15.86 A | 0.5% |
| TcVoc | -0.2 %/°C | -0.2 %/°C | ±0.000 %/°C |
| TcPmax | -0.26 %/°C | -0.26 %/°C | ±0.000 %/°C |
655 W
TOPCon| Parameter | Original | Replacement | Deviation |
|---|---|---|---|
| Voc | 49.62 V | 49.82 V | 0.4% |
| Vmpp | 40.88 V | 41.08 V | 0.5% |
| Isc | 16.46 A | 16.62 A | 1.0% |
| Impp | 15.78 A | 15.94 A | 1.0% |
| TcVoc | -0.2 %/°C | -0.2 %/°C | ±0.000 %/°C |
| TcPmax | -0.26 %/°C | -0.26 %/°C | ±0.000 %/°C |
660 W
TOPCon| Parameter | Original | Replacement | Deviation |
|---|---|---|---|
| Voc | 49.62 V | 49.92 V | 0.6% |
| Vmpp | 40.88 V | 41.18 V | 0.7% |
| Isc | 16.46 A | 16.7 A | 1.5% |
| Impp | 15.78 A | 16.03 A | 1.6% |
| TcVoc | -0.2 %/°C | -0.2 %/°C | ±0.000 %/°C |
| TcPmax | -0.26 %/°C | -0.26 %/°C | ±0.000 %/°C |
665 W
TOPCon| Parameter | Original | Replacement | Deviation |
|---|---|---|---|
| Voc | 49.62 V | 50.02 V | 0.8% |
| Vmpp | 40.88 V | 41.28 V | 1.0% |
| Isc | 16.46 A | 16.78 A | 1.9% |
| Impp | 15.78 A | 16.11 A | 2.1% |
| TcVoc | -0.2 %/°C | -0.2 %/°C | ±0.000 %/°C |
| TcPmax | -0.26 %/°C | -0.26 %/°C | ±0.000 %/°C |
String Compatibility Calculator
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Panel Matcher
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How the Algorithm Works
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Voc
49.62 V
Vmpp
40.88 V
Isc
16.46 A
Impp
15.78 A
TcVoc
-0.2 %/°C
TcPmax
-0.26 %/°C
Pmax
645 W
Cells
66
Bifaciality
75%
Length
2382 mm
Width
1134 mm
Thickness
30 mm
Weight
33.5 kg
The TCL Zhonghuan HSM-BD66-GR645 is a 645 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 |
|---|---|---|---|
| HSM-BD66-GR640 | 640 W | 49.52 V | 16.38 A |
| HSM-BD66-GR650 | 650 W | 49.72 V | 16.54 A |
| HSM-BD66-GR655 | 655 W | 49.82 V | 16.62 A |
| HSM-BD66-GR660 | 660 W | 49.92 V | 16.7 A |
| HSM-BD66-GR665 | 665 W | 50.02 V | 16.78 A |
The most critical specs to match are: cell count (must be exactly 66), Voc close to 49.62 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 TCL Zhonghuan HSM-BD66-GR645.