--- title: "Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM640N-66HL4M-BDV - Solar Panel Comparison | ComparePV" description: "Compare Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM640N-66HL4M-BDV side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm640n-66hl4m-bdv" updated: 2026-09-11 --- # Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM640N-66HL4M-BDV Identical on every published parameter All 19 comparable parameters agree. Two records this alike are usually one panel sold under two names, or two bins of the same production line - decide on price and on who you would rather buy from. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Jinko Solar JKM635N-66HL4M-BDV](https://comparepv.com/panel/jinko-solar-jkm635n-66hl4m-bdv) | [Jinko Solar JKM640N-66HL4M-BDV](https://comparepv.com/panel/jinko-solar-jkm640n-66hl4m-bdv) | | Manufacturer | Jinko Solar | Jinko Solar | | Power | 635 Wp | 640 Wp | | Efficiency | 23.51 % | 23.69 % | | Technology | N-type | N-type | ## Every compared parameter | Parameter | JKM635N-66HL4M-BDV | JKM640N-66HL4M-BDV | | --- | --- | --- | | Rated power | 635 Wp | 640 Wp | | Module efficiency | 23.51 % | 23.69 % | | Power density | 235.1 Wp/m² | 236.9 Wp/m² | | Open-circuit voltage | 49.68 V | 49.88 V | | Voltage at max power | 41.16 V | 41.30 V | | Short-circuit current | 16.26 A | 16.32 A | | Current at max power | 15.43 A | 15.50 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2382x1134x30 mm | 2382x1134x30 mm | | Module area | 2.701 m² | 2.701 m² | | Weight | 32.4 kg | 32.4 kg | | Weight per kWp | 51.0 kg/kWp | 50.6 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | N-type | N-type | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.290 %/°C), so a warmer roof scales both curves by the same factor: the totals fall together and neither panel gains on the other. - **Cumulative output, JKM635N-66HL4M-BDV:** 21,306 kWh - **Cumulative output, JKM640N-66HL4M-BDV:** 21,473 kWh - **Gap:** 167 kWh ## Output when hot | Condition | Cell temperature | JKM635N-66HL4M-BDV | JKM640N-66HL4M-BDV | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 635 W | 640 W | 100.0% of rated power | | Cool, bright day | 40 °C | 607 W | 612 W | 95.7% of rated power | | Typical summer roof | 55 °C | 580 W | 584 W | 91.3% of rated power | | Hot roof | 70 °C | 552 W | 556 W | 87.0% of rated power | ## Against the whole database | Measure | JKM635N-66HL4M-BDV | JKM640N-66HL4M-BDV | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #696 | #580 | 14,005 | JKM640N-66HL4M-BDV leads by 116 places | | Power density | #741 | #521 | 14,005 | JKM640N-66HL4M-BDV leads by 220 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #4,372 | #4,069 | 14,005 | JKM640N-66HL4M-BDV leads by 303 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,741 | #1,530 | 14,005 | JKM640N-66HL4M-BDV leads by 211 places | ## Questions ### Which panel is better: Jinko Solar JKM635N-66HL4M-BDV or Jinko Solar JKM640N-66HL4M-BDV? According to our database: **Jinko Solar JKM640N-66HL4M-BDV** has higher module efficiency (**23.69%** vs **23.51%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Jinko Solar JKM635N-66HL4M-BDV and Jinko Solar JKM640N-66HL4M-BDV? **Jinko Solar JKM635N-66HL4M-BDV** has a module efficiency of **23.51%**, while **Jinko Solar JKM640N-66HL4M-BDV** is **23.69%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Jinko Solar JKM635N-66HL4M-BDV use vs Jinko Solar JKM640N-66HL4M-BDV? **Jinko Solar JKM635N-66HL4M-BDV** uses **N-type** cells; **Jinko Solar JKM640N-66HL4M-BDV** uses **N-type**. 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 Jinko Solar JKM635N-66HL4M-BDV and Jinko Solar JKM640N-66HL4M-BDV? **Jinko Solar JKM635N-66HL4M-BDV** has a **30 years** power warranty; **Jinko Solar JKM640N-66HL4M-BDV** has a **30 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 Jinko Solar JKM635N-66HL4M-BDV and Jinko Solar JKM640N-66HL4M-BDV bifacial panels? Both **Jinko Solar JKM635N-66HL4M-BDV** and **Jinko Solar JKM640N-66HL4M-BDV** are bifacial - they capture reflected light from the ground, which can add 5**-15%** more annual energy on ground-mount or elevated rooftop installations with a light surface beneath. ## Related comparisons - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM630N-66HL4M-BDV](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm630n-66hl4m-bdv) - The same specification on paper - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM625N-66HL4M-BDV](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm625n-66hl4m-bdv) - 3 differences, the largest is module efficiency - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM620N-66HL4M-BDV](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm620n-66hl4m-bdv) - 3 differences, the largest is module efficiency - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM615N-66HL4M-BDV](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm615n-66hl4m-bdv) - 3 differences, the largest is module efficiency - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM710-735N-66HL5-BDV-Z3-EU (735W bin)](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinkosolar-jkm710-735n-66hl5-bdv-z3-eu-735w-bin) - 7 differences, the largest is rated power - [Jinko Solar JKM635N-66HL4M-BDV vs Jinko Solar JKM735N-66HL5-BDV-Z3-EU](https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm735n-66hl5-bdv-z3-eu) - 7 differences, the largest is rated power --- Source: https://comparepv.com/compare/jinko-solar-jkm635n-66hl4m-bdv/jinko-solar-jkm640n-66hl4m-bdv 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.