--- title: "Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-400-COM - Solar Panel Comparison | ComparePV" description: "Compare Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-400-COM side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-400-com" updated: 2026-09-11 --- # Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-400-COM 400-COM leads on the differences that matter The largest is module efficiency: 0.50 pp more efficient. 15 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Maxeon SPR-MAX3-390-COM](https://comparepv.com/panel/maxeon-spr-max3-390-com) | [Maxeon SPR-MAX3-400-COM](https://comparepv.com/panel/maxeon-spr-max3-400-com) | | Manufacturer | Maxeon | Maxeon | | Power | 390 Wp | 400 Wp | | Efficiency | 22.10 % | 22.60 % | | Technology | Back Contact | Back Contact | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 390-COM | 400-COM | Difference | | --- | --- | --- | --- | | Module efficiency | 22.10 % | 22.60 % | +0.50 pp for 400-COM | | Power density | 220.6 Wp/m² | 226.3 Wp/m² | +5.7 Wp/m² for 400-COM | | Rated power | 390 Wp | 400 Wp | +10 W for 400-COM | | Voltage at max power | 64.50 V | 66.00 V | 1.50 V apart | ## Every compared parameter | Parameter | 390-COM | 400-COM | | --- | --- | --- | | Rated power | 390 Wp | 400 Wp | | Module efficiency | 22.10 % | 22.60 % | | Power density | 220.6 Wp/m² | 226.3 Wp/m² | | Open-circuit voltage | 75.30 V | 75.40 V | | Voltage at max power | 64.50 V | 66.00 V | | Short-circuit current | 6.55 A | 6.57 A | | Current at max power | 6.05 A | 6.07 A | | Temperature coefficient | -0.270 %/°C | -0.270 %/°C | | Dimensions | 1690x1046x40 mm | 1690x1046x40 mm | | Module area | 1.768 m² | 1.768 m² | | Weight | 19.0 kg | 19.0 kg | | Weight per kWp | 48.7 kg/kWp | 47.5 kg/kWp | | Product warranty | 40 yrs | 40 yrs | | Performance warranty | 40 yrs | 40 yrs | | Annual degradation | 0.25 %/yr | 0.25 %/yr | | Cell technology | Back Contact | Back Contact | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 104 | 104 | | 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 (-0.270 %/°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, 390-COM:** 13,250 kWh - **Cumulative output, 400-COM:** 13,590 kWh - **Gap:** 340 kWh ## Output when hot | Condition | Cell temperature | 390-COM | 400-COM | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 390 W | 400 W | 100.0% of rated power | | Cool, bright day | 40 °C | 374 W | 384 W | 96.0% of rated power | | Typical summer roof | 55 °C | 358 W | 368 W | 91.9% of rated power | | Hot roof | 70 °C | 343 W | 351 W | 87.8% of rated power | ## Against the whole database | Measure | 390-COM | 400-COM | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #6,012 | #3,658 | 14,005 | 400-COM leads by 2,354 places | | Power density | #6,156 | #3,671 | 14,005 | 400-COM leads by 2,485 places | | Heat behaviour | #1,280 | #1,280 | 14,005 | Tied - the same position in the database | | Weight | #2,430 | #1,726 | 14,005 | 400-COM leads by 704 places | | Warranty | #1 | #1 | 14,005 | Tied - the same position in the database | | Overall | #3,453 | #2,534 | 14,005 | 400-COM leads by 919 places | ## Questions ### Which panel is better: Maxeon SPR-MAX3-390-COM or Maxeon SPR-MAX3-400-COM? According to our database: **Maxeon SPR-MAX3-400-COM** has higher module efficiency (**22.60%** vs **22.10%**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Maxeon SPR-MAX3-390-COM and Maxeon SPR-MAX3-400-COM? **Maxeon SPR-MAX3-390-COM** has a module efficiency of **22.10%**, while **Maxeon SPR-MAX3-400-COM** is **22.60%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Maxeon SPR-MAX3-390-COM use vs Maxeon SPR-MAX3-400-COM? **Maxeon SPR-MAX3-390-COM** uses **Back Contact** cells; **Maxeon SPR-MAX3-400-COM** uses **Back Contact**. 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 Maxeon SPR-MAX3-390-COM and Maxeon SPR-MAX3-400-COM? **Maxeon SPR-MAX3-390-COM** has a **40 years** power warranty; **Maxeon SPR-MAX3-400-COM** has a **40 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 - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-430-R](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-430-r) - 11 differences, the largest is rated power - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-425-R](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-425-r) - 11 differences, the largest is rated power - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-415-R](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-415-r) - 11 differences, the largest is rated power - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-380-COM](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-380-com) - 4 differences, the largest is module efficiency - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-375-BLK](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-375-blk) - 3 differences, the largest is module efficiency - [Maxeon SPR-MAX3-390-COM vs Maxeon SPR-MAX3-370-COM](https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-370-com) - 7 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/maxeon-spr-max3-390-com/maxeon-spr-max3-400-com 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.