420 W TOPCon solar panel with 108 cells. Voc 38.64 V · Isc 13.46 A · TcVoc -0.24%/°C.
Select the panel you want to replace
Panel not in the catalogue?
355 of the 4,444 panels in the catalogue can replace Qcells Q.TRON BLK M-G2+ 420 (405-425 W). Before you buy, check your pick in the string calculator with your inverter.
Close or harmlessNoticeableLarge 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 95–96 % · 10 models
Small differences within tolerance — safe once verified in the calculator with your inverter.
Match 80–93 % · 109 models
Noticeable differences — the string voltage and current need a careful check.
Match 60–79 % · 212 models
Large differences — a real risk of a mismatched string; prefer a closer panel.
Match 51–59 % · 24 models
String Compatibility Calculator
Verify the replacement panel works with your inverter
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How the Algorithm Works
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Voc
38.64 V
Vmpp
32.77 V
Isc
13.46 A
Impp
12.82 A
TcVoc
-0.24 %/°C
TcPmax
-0.3 %/°C
Pmax
420 W
Cells
108
Length
1692 mm
Width
1134 mm
Thickness
32 mm
Weight
21.5 kg
The Qcells Q.TRON BLK M-G2+ 420 (405-425 W) is a 420 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 |
|---|---|---|---|
| Q.TRON BLK M-G2+ 405 (405-425 W) | 405 W | 38.56 V | 13.35 A |
| Q.TRON BLK M-G2+ 410 (405-425 W) | 410 W | 38.58 V | 13.39 A |
| Q.TRON BLK M-G2+ 415 (405-425 W) | 415 W | 38.61 V | 13.42 A |
| Q.TRON BLK M-G2+ 425 (405-425 W) | 425 W | 38.67 V | 13.49 A |
Match the voltage, not the cell count or the wattage. The replacement's open-circuit voltage should be no more than 2 % above 38.64 V and its working voltage within 5 % of the original; its working current should not be more than 3 % lower, because the weakest panel in a string sets the current for all of them. A temperature coefficient closer to zero than -0.24 %/°C is fine — it adds less voltage in frost. The finder above screens the whole catalogue by these rules.
Yes, if its voltage matches. A higher-wattage panel of the same voltage simply has more current, and a string only carries as much as its weakest panel gives, so the extra goes unused at no risk to the string. Two things to check: its higher short-circuit current against the inverter's rating, and its frame, which is usually larger. The finder shows both; verify the pick in the String Compatibility Calculator with your inverter before installing.
If its Voc is higher, the string comes closer to the inverter's maximum voltage on frosty mornings, when voltage climbs by the TcVoc coefficient; if its Vmpp is lower, the string can drop out of the inverter's working range (MPPT) on hot days. The finder scores each difference only in the direction that hurts — a lower Voc or a flatter coefficient costs nothing — and ranks candidates by how closely they match the Qcells Q.TRON BLK M-G2+ 420 (405-425 W).