--- title: "Hyundai HiS-T635NJ vs Hyundai HIE-S400VG - Solar Panel Comparison | ComparePV" description: "Compare Hyundai HiS-T635NJ vs Hyundai HIE-S400VG side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/hd-hyundai-energy-solutions-his-t635nj/hyundai-hie-s400vg" image: "https://comparepv.com/og/compare/panels/hd-hyundai-energy-solutions-his-t635nj/hyundai-hie-s400vg.png" updated: 2026-09-11 --- # Hyundai HiS-T635NJ vs Hyundai HIE-S400VG HiS-T635NJ leads on the differences that matter The largest is module efficiency: 2.32 pp more efficient. 2 of 18 comparable parameters are identical, with 1 more left out because at least one datasheet does not publish it. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Hyundai HiS-T635NJ](https://comparepv.com/panel/hd-hyundai-energy-solutions-his-t635nj) | [Hyundai HIE-S400VG](https://comparepv.com/panel/hyundai-hie-s400vg) | | Manufacturer | Hyundai | Hyundai | | Power | 635 Wp | 400 Wp | | Efficiency | 22.72 % | 20.40 % | | Technology | TOPCon | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | HiS-T635NJ | HIE-S400VG | Difference | | --- | --- | --- | --- | | Module efficiency | 22.72 % | 20.40 % | +2.32 pp for HiS-T635NJ | | Temperature coefficient | -0.290 %/°C | -0.340 %/°C | +0.050 %/°C for HiS-T635NJ | | Rated power | 635 Wp | 400 Wp | +235 W for HiS-T635NJ | | Power density | 227.2 Wp/m² | 204.1 Wp/m² | +23.0 Wp/m² for HiS-T635NJ | | Performance warranty | 30 yrs | 25 yrs | +5 yrs for HiS-T635NJ | | Annual degradation | 0.40 %/yr | 0.55 %/yr | -0.15 %/yr for HiS-T635NJ | | Weight | 34.7 kg | 22.0 kg | -12.7 kg for HIE-S400VG | | Product warranty | 12 yrs | 25 yrs | +13 yrs for HIE-S400VG | | Open-circuit voltage | 57.56 V | 46.40 V | 11.16 V apart | | Short-circuit current | 13.98 A | 10.97 A | 3.01 A apart | | Module area | 2.795 m² | 1.960 m² | 0.836 m² apart | | Cell technology | TOPCon | PERC | TOPCon vs PERC | | Voltage at max power | 47.57 V | 38.60 V | 8.97 V apart | | Current at max power | 13.35 A | 10.36 A | 2.99 A apart | | Bifacial | Yes | No | Yes vs No | | Dimensions | 2465x1134x30 mm | 1719x1140x35 mm | 2465x1134x30 mm vs 1719x1140x35 mm | ## Every compared parameter | Parameter | HiS-T635NJ | HIE-S400VG | | --- | --- | --- | | Rated power | 635 Wp | 400 Wp | | Module efficiency | 22.72 % | 20.40 % | | Power density | 227.2 Wp/m² | 204.1 Wp/m² | | Open-circuit voltage | 57.56 V | 46.40 V | | Voltage at max power | 47.57 V | 38.60 V | | Short-circuit current | 13.98 A | 10.97 A | | Current at max power | 13.35 A | 10.36 A | | Temperature coefficient | -0.290 %/°C | -0.340 %/°C | | Dimensions | 2465x1134x30 mm | 1719x1140x35 mm | | Module area | 2.795 m² | 1.960 m² | | Weight | 34.7 kg | 22.0 kg | | Weight per kWp | 54.6 kg/kWp | 55.0 kg/kWp | | Product warranty | 12 yrs | 25 yrs | | Performance warranty | 30 yrs | 25 yrs | | Annual degradation | 0.40 %/yr | 0.55 %/yr | | Cell technology | TOPCon | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 156 | - | | Bifacial | Yes | No | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, HiS-T635NJ:** 21,306 kWh - **Cumulative output, HIE-S400VG:** 12,964 kWh - **Gap:** 8,342 kWh ## Output when hot | Condition | Cell temperature | HiS-T635NJ | HIE-S400VG | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 635 W | 400 W | 100.0% of rated power | | Cool, bright day | 40 °C | 607 W | 380 W | 94.9% of rated power | | Typical summer roof | 55 °C | 580 W | 359 W | 89.8% of rated power | | Hot roof | 70 °C | 552 W | 339 W | 84.7% of rated power | ## Against the whole database | Measure | HiS-T635NJ | HIE-S400VG | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #3,302 | #11,680 | 14,129 | HiS-T635NJ leads by 8,378 places | | Power density | #3,309 | #11,678 | 14,129 | HiS-T635NJ leads by 8,369 places | | Heat behaviour | #2,220 | #8,846 | 14,129 | HiS-T635NJ leads by 6,626 places | | Weight | #9,102 | #9,445 | 14,129 | HiS-T635NJ leads by 343 places | | Warranty | #21 | #9,912 | 14,129 | HiS-T635NJ leads by 9,891 places | | Overall | #2,387 | #10,832 | 14,129 | HiS-T635NJ leads by 8,445 places | ## Questions ### Which panel is better: Hyundai HiS-T635NJ or Hyundai HIE-S400VG? According to our database: **Hyundai HiS-T635NJ** has higher module efficiency (**22.72%** vs **20.40%**); **Hyundai HiS-T635NJ** tolerates heat better (temp coeff **-0.290%/°C** vs **-0.340%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Hyundai HiS-T635NJ and Hyundai HIE-S400VG? **Hyundai HiS-T635NJ** has a module efficiency of **22.72%**, while **Hyundai HIE-S400VG** is **20.40%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Hyundai HiS-T635NJ use vs Hyundai HIE-S400VG? **Hyundai HiS-T635NJ** uses **TOPCon** cells; **Hyundai HIE-S400VG** uses **PERC**. Modern **n-type** technologies (**TOPCon**, **HJT**, BC) typically deliver higher efficiency and lower degradation compared to older **PERC** (p-type) cells. ### What is the warranty on Hyundai HiS-T635NJ and Hyundai HIE-S400VG? **Hyundai HiS-T635NJ** has a **30 years** power warranty; **Hyundai HIE-S400VG** has a **25 years** power warranty. The power warranty guarantees a minimum percentage of rated output at the end of the warranty period (typically 80**-87%**). Product (materials) warranties are usually shorter. ### Are Hyundai HiS-T635NJ and Hyundai HIE-S400VG bifacial panels? **Hyundai HiS-T635NJ** is bifacial (captures light from both faces); **Hyundai HIE-S400VG** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath. ## Related comparisons - [Hyundai HiS-T635NJ vs Hyundai HiS-T640NJ](https://comparepv.com/compare/hd-hyundai-energy-solutions-his-t635nj/hd-hyundai-energy-solutions-his-t640nj) - The same specification on paper - [Hyundai HiS-T635NJ vs Hyundai HiS-T630NJ](https://comparepv.com/compare/hd-hyundai-energy-solutions-his-t635nj/hd-hyundai-energy-solutions-his-t630nj) - The same specification on paper - [Hyundai HIE-S400VG vs Hyundai HIE-S410VG](https://comparepv.com/compare/hyundai-hie-s400vg/hyundai-hie-s410vg) - 3 differences, the largest is module efficiency - [Hyundai HIE-S400VG vs Hyundai HIE-S405VG](https://comparepv.com/compare/hyundai-hie-s400vg/hyundai-hie-s405vg) - One difference: module efficiency - [Hyundai HIE-S400VG vs Hyundai HIE-S395VG](https://comparepv.com/compare/hyundai-hie-s400vg/hyundai-hie-s395vg) - One difference: module efficiency - [Hyundai HIE-S400VG vs Hyundai HIE-S390VG](https://comparepv.com/compare/hyundai-hie-s400vg/hyundai-hie-s390vg) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/hd-hyundai-energy-solutions-his-t635nj/hyundai-hie-s400vg Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.