--- title: "JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-405/MR - Solar Panel Comparison | ComparePV" description: "Compare JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-405/MR 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-jam54s30-400-mr/ja-solar-jam54s30-405-mr" updated: 2026-09-11 --- # JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-405/MR 405/MR leads on the differences that matter The largest is module efficiency: 0.20 pp more efficient. 18 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [JA Solar JAM54S30-400/MR](https://comparepv.com/panel/ja-solar-jam54s30-400-mr) | [JA Solar JAM54S30-405/MR](https://comparepv.com/panel/ja-solar-jam54s30-405-mr) | | Manufacturer | JA Solar | JA Solar | | Power | 400 Wp | 405 Wp | | Efficiency | 20.50 % | 20.70 % | | Technology | PERC | PERC | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 400/MR | 405/MR | Difference | | --- | --- | --- | --- | | Module efficiency | 20.50 % | 20.70 % | +0.20 pp for 405/MR | ## Every compared parameter | Parameter | 400/MR | 405/MR | | --- | --- | --- | | Rated power | 400 Wp | 405 Wp | | Module efficiency | 20.50 % | 20.70 % | | Power density | 204.8 Wp/m² | 207.4 Wp/m² | | Open-circuit voltage | 37.07 V | 37.23 V | | Voltage at max power | 31.01 V | 31.21 V | | Short-circuit current | 13.79 A | 13.87 A | | Current at max power | 12.90 A | 12.98 A | | Temperature coefficient | -0.350 %/°C | -0.350 %/°C | | Dimensions | 1722x1134x30 mm | 1722x1134x30 mm | | Module area | 1.953 m² | 1.953 m² | | Weight | 19.5 kg | 19.5 kg | | Weight per kWp | 48.8 kg/kWp | 48.1 kg/kWp | | Product warranty | 12 yrs | 12 yrs | | Performance warranty | 25 yrs | 25 yrs | | Annual degradation | 0.55 %/yr | 0.55 %/yr | | Cell technology | PERC | PERC | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 108 | 108 | | Bifacial | No | No | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year Same temp coeff. for both panels (-0.350 %/°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, 400/MR:** 12,964 kWh - **Cumulative output, 405/MR:** 13,126 kWh - **Gap:** 162 kWh ## Output when hot | Condition | Cell temperature | 400/MR | 405/MR | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 400 W | 405 W | 100.0% of rated power | | Cool, bright day | 40 °C | 379 W | 384 W | 94.8% of rated power | | Typical summer roof | 55 °C | 358 W | 362 W | 89.5% of rated power | | Hot roof | 70 °C | 337 W | 341 W | 84.2% of rated power | ## Against the whole database | Measure | 400/MR | 405/MR | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #11,308 | #10,764 | 14,005 | 405/MR leads by 544 places | | Power density | #11,370 | #10,626 | 14,005 | 405/MR leads by 744 places | | Heat behaviour | #10,419 | #10,419 | 14,005 | Tied - the same position in the database | | Weight | #2,441 | #2,073 | 14,005 | 405/MR leads by 368 places | | Warranty | #9,798 | #9,798 | 14,005 | Tied - the same position in the database | | Overall | #12,072 | #11,881 | 14,005 | 405/MR leads by 191 places | ## Questions ### Which panel is better: JA Solar JAM54S30-400/MR or JA Solar JAM54S30-405/MR? According to our database: **JA Solar JAM54S30-405/MR** has higher module efficiency (**20.70%** vs **20.50%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of JA Solar JAM54S30-400/MR and JA Solar JAM54S30-405/MR? **JA Solar JAM54S30-400/MR** has a module efficiency of **20.50%**, while **JA Solar JAM54S30-405/MR** is **20.70%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does JA Solar JAM54S30-400/MR use vs JA Solar JAM54S30-405/MR? **JA Solar JAM54S30-400/MR** uses **PERC** cells; **JA Solar JAM54S30-405/MR** 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 JA Solar JAM54S30-400/MR and JA Solar JAM54S30-405/MR? **JA Solar JAM54S30-400/MR** has a **25 years** power warranty; **JA Solar JAM54S30-405/MR** 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. ## Related comparisons - [JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-415/MR](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam54s30-415-mr) - 3 differences, the largest is module efficiency - [JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-410/MR](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam54s30-410-mr) - 3 differences, the largest is module efficiency - [JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-395/MR](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam54s30-395-mr) - One difference: module efficiency - [JA Solar JAM54S30-400/MR vs JA Solar JAM54S30-390/MR](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam54s30-390-mr) - 3 differences, the largest is module efficiency - [JA Solar JAM54S30-400/MR vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam66d46-740-lb) - 17 differences, the largest is module efficiency - [JA Solar JAM54S30-400/MR vs JA Solar JAM66D46-735/LB](https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam66d46-735-lb) - 17 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/ja-solar-jam54s30-400-mr/ja-solar-jam54s30-405-mr 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.