---
title: "JA Solar JAM54S30-405/MR vs JA Solar JAM66D46-735/LB - Solar Panel Comparison | ComparePV"
description: "Compare JA Solar JAM54S30-405/MR vs JA Solar JAM66D46-735/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-jam54s30-405-mr/ja-solar-jam66d46-735-lb"
updated: 2026-09-11
---

# JA Solar JAM54S30-405/MR vs JA Solar JAM66D46-735/LB

JAM66D46-735/LB leads on the differences that matter

The largest is module efficiency: 3.00 pp more efficient. 2 of 19 comparable parameters are identical.


## The two panels


| Attribute | A | B |
| --- | --- | --- |
| Panel | [JA Solar JAM54S30-405/MR](https://comparepv.com/panel/ja-solar-jam54s30-405-mr) | [JA Solar JAM66D46-735/LB](https://comparepv.com/panel/ja-solar-jam66d46-735-lb) |
| Manufacturer | JA Solar | JA Solar |
| Power | 405 Wp | 735 Wp |
| Efficiency | 20.70 % | 23.70 % |
| Technology | PERC | TOPCon |


## Where they differ

Ranked by how much the difference matters, not by datasheet order.


| Parameter | JAM54S30-405/MR | JAM66D46-735/LB | Difference |
| --- | --- | --- | --- |
| Module efficiency | 20.70 % | 23.70 % | +3.00 pp for JAM66D46-735/LB |
| Temperature coefficient | -0.350 %/°C | -0.290 %/°C | +0.060 %/°C for JAM66D46-735/LB |
| Rated power | 405 Wp | 735 Wp | +330 W for JAM66D46-735/LB |
| Power density | 207.4 Wp/m² | 236.6 Wp/m² | +29.2 Wp/m² for JAM66D46-735/LB |
| Performance warranty | 25 yrs | 30 yrs | +5 yrs for JAM66D46-735/LB |
| Annual degradation | 0.55 %/yr | 0.40 %/yr | -0.15 %/yr for JAM66D46-735/LB |
| Weight | 19.5 kg | 38.2 kg | -18.7 kg for JAM54S30-405/MR |
| Open-circuit voltage | 37.23 V | 49.60 V | 12.37 V apart |
| Short-circuit current | 13.87 A | 18.70 A | 4.83 A apart |
| Module area | 1.953 m² | 3.106 m² | 1.154 m² apart |
| Weight per kWp | 48.1 kg/kWp | 52.0 kg/kWp | -3.8 kg/kWp for JAM54S30-405/MR |
| Cell technology | PERC | TOPCon | PERC vs TOPCon |
| Voltage at max power | 31.21 V | 41.77 V | 10.56 V apart |
| Current at max power | 12.98 A | 17.60 A | 4.62 A apart |
| Cell count | 108 | 132 | 24 cells apart |
| Bifacial | No | Yes | No vs Yes |
| Dimensions | 1722x1134x30 mm | 2384x1303x33 mm | 1722x1134x30 mm vs 2384x1303x33 mm |


## Every compared parameter


| Parameter | JAM54S30-405/MR | JAM66D46-735/LB |
| --- | --- | --- |
| Rated power | 405 Wp | 735 Wp |
| Module efficiency | 20.70 % | 23.70 % |
| Power density | 207.4 Wp/m² | 236.6 Wp/m² |
| Open-circuit voltage | 37.23 V | 49.60 V |
| Voltage at max power | 31.21 V | 41.77 V |
| Short-circuit current | 13.87 A | 18.70 A |
| Current at max power | 12.98 A | 17.60 A |
| Temperature coefficient | -0.350 %/°C | -0.290 %/°C |
| Dimensions | 1722x1134x30 mm | 2384x1303x33 mm |
| Module area | 1.953 m² | 3.106 m² |
| Weight | 19.5 kg | 38.2 kg |
| Weight per kWp | 48.1 kg/kWp | 52.0 kg/kWp |
| Product warranty | 12 yrs | 12 yrs |
| Performance warranty | 25 yrs | 30 yrs |
| Annual degradation | 0.55 %/yr | 0.40 %/yr |
| Cell technology | PERC | TOPCon |
| Cell type | Monocrystalline | Monocrystalline |
| Cell count | 108 | 132 |
| Bifacial | No | Yes |


## Thirty-year yield

Each panel's own declared degradation curve, at 1,200 kWh/kWp a year

- **Cumulative output, JAM54S30-405/MR:** 13,126 kWh
- **Cumulative output, JAM66D46-735/LB:** 24,661 kWh
- **Gap:** 11,535 kWh


## Output when hot


| Condition | Cell temperature | JAM54S30-405/MR | JAM66D46-735/LB | Retained |
| --- | --- | --- | --- | --- |
| Standard test conditions | 25 °C | 405 W | 735 W | 100.0% of rated power |
| Cool, bright day | 40 °C | 384 W | 703 W | 94.8% of rated power |
| Typical summer roof | 55 °C | 362 W | 671 W | 89.5% of rated power |
| Hot roof | 70 °C | 341 W | 639 W | 84.2% of rated power |


## Against the whole database


| Measure | JAM54S30-405/MR | JAM66D46-735/LB | Out of | Note |
| --- | --- | --- | --- | --- |
| Efficiency | #10,764 | #517 | 14,005 | JAM66D46-735/LB leads by 10,247 places |
| Power density | #10,626 | #582 | 14,005 | JAM66D46-735/LB leads by 10,044 places |
| Heat behaviour | #10,419 | #2,165 | 14,005 | JAM66D46-735/LB leads by 8,254 places |
| Weight | #2,073 | #5,413 | 14,005 | JAM54S30-405/MR leads by 3,340 places |
| Warranty | #9,798 | #21 | 14,005 | JAM66D46-735/LB leads by 9,777 places |
| Overall | #11,881 | #233 | 14,005 | JAM66D46-735/LB leads by 11,648 places |


## Questions


### Which panel is better: JA Solar JAM54S30-405/MR or JA Solar JAM66D46-735/LB?

According to our database: **JA Solar JAM66D46-735/LB** has higher module efficiency (**23.70%** vs **20.70%**); **JA Solar JAM66D46-735/LB** tolerates heat better (temp coeff **-0.290%/°C** vs **-0.350%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture.


### What is the efficiency of JA Solar JAM54S30-405/MR and JA Solar JAM66D46-735/LB?

**JA Solar JAM54S30-405/MR** has a module efficiency of **20.70%**, while **JA Solar JAM66D46-735/LB** is **23.70%**. Higher efficiency means more electricity from the same roof area - useful when space is limited.


### What cell technology does JA Solar JAM54S30-405/MR use vs JA Solar JAM66D46-735/LB?

**JA Solar JAM54S30-405/MR** uses **PERC** cells; **JA Solar JAM66D46-735/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 JAM54S30-405/MR and JA Solar JAM66D46-735/LB?

**JA Solar JAM54S30-405/MR** has a **25 years** power warranty; **JA Solar JAM66D46-735/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 JAM54S30-405/MR and JA Solar JAM66D46-735/LB bifacial panels?

**JA Solar JAM66D46-735/LB** is bifacial (captures light from both faces); **JA Solar JAM54S30-405/MR** is monofacial. Bifacial panels work best on ground mounts or raised structures with a light-coloured surface underneath.


## Related comparisons

- [JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-415/MR](https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam54s30-415-mr) - 3 differences, the largest is module efficiency
- [JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-410/MR](https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam54s30-410-mr) - One difference: module efficiency
- [JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-400/MR](https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam54s30-400-mr) - One difference: module efficiency
- [JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-395/MR](https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam54s30-395-mr) - 3 differences, the largest is module efficiency
- [JA Solar JAM54S30-405/MR vs JA Solar JAM54S30-390/MR](https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam54s30-390-mr) - 3 differences, the largest is module efficiency
- [JA Solar JAM66D46-735/LB vs JA Solar JAM66D46-740/LB](https://comparepv.com/compare/ja-solar-jam66d46-735-lb/ja-solar-jam66d46-740-lb) - The same specification on paper


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Source: https://comparepv.com/compare/ja-solar-jam54s30-405-mr/ja-solar-jam66d46-735-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.