--- title: "JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-720/LB - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-720/LB side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-720-lb" updated: 2026-09-11 --- # JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-720/LB JAM66D45-650/LB leads on the differences that matter The largest is module efficiency: 0.90 pp more efficient. 10 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM66D45-650/LB](https://comparepv.com/panel/ja-solar-jam66d45-650-lb) | [JA Solar JAM66D46-720/LB](https://comparepv.com/panel/ja-solar-jam66d46-720-lb) | | Manufacturer | JA Solar | JA Solar | | Power | 650 Wp | 720 Wp | | Efficiency | 24.10 % | 23.20 % | | Technology | TOPCon | TOPCon | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | JAM66D45-650/LB | JAM66D46-720/LB | Difference | | --- | --- | --- | --- | | Module efficiency | 24.10 % | 23.20 % | +0.90 pp for JAM66D45-650/LB | | Rated power | 650 Wp | 720 Wp | +70 W for JAM66D46-720/LB | | Weight | 33.1 kg | 38.2 kg | -5.1 kg for JAM66D45-650/LB | | Power density | 240.6 Wp/m² | 231.8 Wp/m² | +8.9 Wp/m² for JAM66D45-650/LB | | Module area | 2.701 m² | 3.106 m² | 0.405 m² apart | | Weight per kWp | 50.9 kg/kWp | 53.1 kg/kWp | -2.1 kg/kWp for JAM66D45-650/LB | | Short-circuit current | 17.99 A | 18.59 A | 0.60 A apart | | Current at max power | 16.30 A | 17.48 A | 1.18 A apart | | Dimensions | 2382x1134x30 mm | 2384x1303x33 mm | 2382x1134x30 mm vs 2384x1303x33 mm | ## Every compared parameter | Parameter | JAM66D45-650/LB | JAM66D46-720/LB | | --- | --- | --- | | Rated power | 650 Wp | 720 Wp | | Module efficiency | 24.10 % | 23.20 % | | Power density | 240.6 Wp/m² | 231.8 Wp/m² | | Open-circuit voltage | 49.97 V | 49.00 V | | Voltage at max power | 41.67 V | 41.19 V | | Short-circuit current | 17.99 A | 18.59 A | | Current at max power | 16.30 A | 17.48 A | | Temperature coefficient | -0.290 %/°C | -0.290 %/°C | | Dimensions | 2382x1134x30 mm | 2384x1303x33 mm | | Module area | 2.701 m² | 3.106 m² | | Weight | 33.1 kg | 38.2 kg | | Weight per kWp | 50.9 kg/kWp | 53.1 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.40 %/yr | | Cell technology | TOPCon | TOPCon | | 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, JAM66D45-650/LB:** 21,809 kWh - **Cumulative output, JAM66D46-720/LB:** 24,157 kWh - **Gap:** 2,348 kWh ## Output when hot | Condition | Cell temperature | JAM66D45-650/LB | JAM66D46-720/LB | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 650 W | 720 W | 100.0% of rated power | | Cool, bright day | 40 °C | 622 W | 689 W | 95.7% of rated power | | Typical summer roof | 55 °C | 593 W | 657 W | 91.3% of rated power | | Hot roof | 70 °C | 565 W | 626 W | 87.0% of rated power | ## Against the whole database | Measure | JAM66D45-650/LB | JAM66D46-720/LB | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #219 | #1,306 | 14,005 | JAM66D45-650/LB leads by 1,087 places | | Power density | #233 | #1,347 | 14,005 | JAM66D45-650/LB leads by 1,114 places | | Heat behaviour | #2,165 | #2,165 | 14,005 | Tied - the same position in the database | | Weight | #4,300 | #6,810 | 14,005 | JAM66D45-650/LB leads by 2,510 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,158 | #516 | 14,005 | JAM66D46-720/LB leads by 642 places | ## Questions ### Which panel is better: JA Solar JAM66D45-650/LB or JA Solar JAM66D46-720/LB? According to our database: **JA Solar JAM66D45-650/LB** has higher module efficiency (**24.10%** vs **23.20%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM66D45-650/LB and JA Solar JAM66D46-720/LB? **JA Solar JAM66D45-650/LB** has a module efficiency of **24.10%**, while **JA Solar JAM66D46-720/LB** is **23.20%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM66D45-650/LB use vs JA Solar JAM66D46-720/LB? **JA Solar JAM66D45-650/LB** uses **TOPCon** cells; **JA Solar JAM66D46-720/LB** uses **TOPCon**. 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 JA Solar JAM66D45-650/LB and JA Solar JAM66D46-720/LB? **JA Solar JAM66D45-650/LB** has a **30 years** power warranty; **JA Solar JAM66D46-720/LB** 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 JA Solar JAM66D45-650/LB and JA Solar JAM66D46-720/LB bifacial panels? Both **JA Solar JAM66D45-650/LB** and **JA Solar JAM66D46-720/LB** 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 - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-740-lb) - 7 differences, the largest is rated power - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-735-lb) - 8 differences, the largest is rated power - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-730/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-730-lb) - 8 differences, the largest is rated power - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-725/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-725-lb) - 8 differences, the largest is module efficiency - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-715/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-715-lb) - 10 differences, the largest is module efficiency - [JA Solar JAM66D45-650/LB vs JA Solar JAM66D46-710/LB](https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-710-lb) - 10 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam66d45-650-lb/ja-solar-jam66d46-720-lb 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.