Callsun 420W (2 x 210W) Bifacial 2-Pack

Last updated: October 26, 2026

Callsun 420W (2 x 210W) Bifacial 2-Pack
4.0/5#27 of 61 in 150 W and up rigid panels
4.0

A good-value pair for a 24 V RV, van or cabin system with an MPPT controller, or for a power station wired in parallel. Owners of 12 V PWM setups should pick a lower-voltage panel.

  • 420 WRated output
  • $0.71Price / W
  • 40.3 VOpen-circuit voltage
  • 10 yearsWarranty
Check price at Amazon$299.97

Price checked October 26, 2026. As an Amazon Associate we earn from qualifying purchases.

Pros
  • About 71 cents per watt for two well-documented N-type panels with a 10-year workmanship warranty
  • 34 V operating voltage per panel suits 24 V batteries directly through an MPPT controller, with thinner cable for the same power
  • Split into two halves, so shade on one end costs about half a panel’s output instead of most of it
  • Bifacial back adds output when mounted over a light roof, gravel or snow
Cons
  • Two in series reach about 81 V open-circuit, beyond most portable power stations’ solar inputs, so they usually run in parallel
  • On a 12 V battery the high voltage needs an MPPT controller; a PWM controller wastes much of the output
  • No independent output test yet

How it scores

The rating comes from 4 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.

Specifications

Output
Rated power420 W
Module efficiency19.9% (rated power over panel area)
Claimed efficiency25.6% (cell efficiency; no module efficiency published)
CellsMonocrystalline (N-type, 16BB, quarter-cut cells, wired as two parallel halves for shade tolerance)
BifacialYes
Electrical
Open-circuit voltage (Voc)40.3 V
Voltage at max power (Vmp)34.2 V
Short-circuit current (Isc)6.5 A
Current at max power (Imp)6.1 A
Voc temperature coefficient-0.2%/°C
Series / parallelYes
Connections
Output connectorSolar connectors
Build
Dimensions54.2 x 30.2 x 1.4 in (each panel)
Frameanodized aluminum alloy
Glass3.2 mm tempered
Junction box ratingIP68
Warranty10 years
Output warranty84.5% output after 25 years
Released2026-08

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