645 W TOPCon solar panel with 132 cells. Voc 49.99 V · Isc 16.32 A · TcVoc -0.26%/°C.
Select the panel you want to replace
Panel not in the catalogue?
31 of the 4,444 panels in the catalogue can replace TommaTech TT645-132TNB12R. Before you buy, check your pick in the string calculator with your inverter.
CloseNoticeableLarge differenceTap or click a difference to see what it means for your string.
Near-identical electrics — a drop-in swap for the same string.
Match 100 % · 1 model
Small differences within tolerance — safe once verified in the calculator with your inverter.
Match 84–92 % · 8 models
Noticeable differences — the string voltage and current need a careful check.
Match 61–76 % · 16 models
Large differences — a real risk of a mismatched string; prefer a closer panel.
Match 42–55 % · 6 models
String Compatibility Calculator
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Panel Matcher
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How the Algorithm Works
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Voc
49.99 V
Vmpp
42.02 V
Isc
16.32 A
Impp
15.35 A
TcVoc
-0.26 %/°C
TcPmax
-0.3 %/°C
Pmax
645 W
Cells
132
Length
2382 mm
Width
1134 mm
Thickness
35 mm
Weight
31.1 kg
The TommaTech TT645-132TNB12R 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 |
|---|---|---|---|
| TT620-132TNB12R | 620 W | 48.99 V | 16.02 A |
| TT625-132TNB12R | 625 W | 49.19 V | 16.08 A |
| TT630-132TNB12R | 630 W | 49.39 V | 16.14 A |
| TT635-132TNB12R | 635 W | 49.59 V | 16.2 A |
| TT640-132TNB12R | 640 W | 49.79 V | 16.26 A |
| TT650-132TNB12R | 650 W | 50.19 V | 16.38 A |
| TT655-132TNB12R | 655 W | 50.39 V | 16.44 A |
The most critical specs to match are: cell count (must be exactly 132), Voc close to 49.99 V (within ±5%), and temperature coefficient TcVoc close to -0.26%/°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 TommaTech TT645-132TNB12R.