--- title: "JA Solar JAM54S31-385/MR 385W Solar Panel - Specs & Review | ComparePV" description: "JA Solar JAM54S31-385/MR 385W solar panel. Specs: 19.70% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/ja-solar-jam54s31-385-mr" updated: 2026-09-11 --- # JA Solar JAM54S31-385/MR Light for its output, no clear weak spot 579 panels in the segment PERC 350-400 W ## Identity - **Manufacturer:** JA Solar - **Model:** JAM54S31-385/MR - **Series:** JAM54S31 380-405/MR - **Rated power:** 385 W - **Cell technology:** PERC ## How it compares Compared against segment PERC 350-400 W (579 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 385 W | 380 W | Typical | | | Module efficiency | 19.70% | 19.90% | Typical | 12,511 | | Power density | 197.2 | 199.0 | Typical | 12,493 | | Temperature coefficient | -0.350 | -0.350 | Typical | 10,419 | | Weight (kg) | 19.5 kg | 21.4 kg | Strong - top 7% | | | Performance warranty | 25 yrs | 25 yrs | Typical | 9,798 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 19.70% | 19.90% | Typical | 12,511 | | Power density | 197.2 | 199.0 | Typical | 12,493 | | Temperature coefficient | -0.350 | -0.350 | Typical | 10,419 | | Weight per kWp | 50.6 | 55.8 | Strong - top 7% | 4,091 | | Performance warranty | 25 yrs | 25 yrs | Typical | 9,798 | ### Strengths - **50.6 kg per kWp** - Top 7% of the PERC 350-400 W segment, against a median of 55.8. Ranked 4,091st in the whole database. - **Best for:** Residential, commercial and shaded-installations. ## Specification ### Electrical - **Rated power (Pmax):** 385 W - **Efficiency:** 19.70 % - **Voltage at Pmax (Vmp):** 30.46 V - **Current at Pmax (Imp):** 12.64 A - **Open-circuit voltage (Voc):** 36.71 V - **Short-circuit current (Isc):** 13.52 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.350 %/degC - **Temperature coefficient of Voc:** -0.275 %/degC - **Temperature coefficient of Isc:** 0.045 %/degC - **NOCT:** 45 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell technology:** PERC - **Cell count:** 108 ### Physical - **Length:** 1722 mm - **Width:** 1134 mm - **Thickness:** 30 mm - **Weight:** 19.5 kg - **Area:** 1.95 m2 - **Power density:** 197.2 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **Output guaranteed at end of warranty:** 84.8 % - **First-year degradation:** 2.00 % - **Annual degradation:** 0.55 % - **Output after 30 years:** 316 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 12511 of 14005 | | Power density | 12493 of 14005 | | Temperature coefficient | 10419 of 14005 | | Weight | 4091 of 14005 | | Warranty | 9798 of 14005 | ## Pros - **Half-cut cells + 11-busbar MBB** - Splitting cells in half reduces series resistance and lowers hot-spot risk under partial shading. The 11-busbar MBB layout shortens current paths by up to 30% compared to 5-busbar predecessors, improving energy yield at low irradiance and under diffuse light conditions. - **Tier-1 BNEF bankable manufacturer (Q2 2026)** - JA Solar holds continuous BNEF Tier-1 bankable status, confirmed on the Q2 2026 list. With annual manufacturing capacity exceeding 80 GW and operations since 2005, the company presents minimal counterparty risk for project finance. - **20.7% efficiency competitive within segment** - The 405 Wp variant reaches 20.7% module efficiency — on par with EGing PV STAR (20.74%) and VSUN405-108BMH (20.74%), and above Goldi GS10-M108-BF (20.66%), confirming the series' competitiveness within the 108-cell PERC power class. - **Mechanical durability: 5400/2400 Pa** - IEC 61215 and IEC 61730 certified to withstand 5400 Pa front load (snow) and 2400 Pa rear load (wind) — values relevant to Central European climates where snow load standards reach 1.5–3.0 kN/m² depending on zone. ## Cons - **Discontinued series (EOL ~2023)** - Production of the JAM54S31 380-405/MR was discontinued around 2023. Module availability is limited to remaining warehouse stock, complicating replacement sourcing for damaged units and potentially affecting warranty claim processing given the inactive production line. - **P-type PERC – higher LID and degradation rate** - P-type PERC cells exhibit initial LID of 1.5–3% due to boron-oxygen defects, versus 0.2–0.5% for N-type TOPCon. Annual degradation for PERC runs at 0.45–0.55% vs. 0.30–0.40% for TOPCon, resulting in ~84.8% power retention after 25 years compared to >90% for TOPCon modules — translating to a higher LCOE for new installations. - **Monofacial only – no bifacial gain** - The series is monofacial (is\_bifacial = false), while comparable products in the same power class (e.g., Goldi GS10-M108-BF) offer an additional 5–15% rear-side yield under favorable albedo conditions. At identical nameplate power, this results in lower real-world annual energy output on installations over light-colored surfaces. ## About this series The JA Solar JAM54S31 380-405/MR series is designed for maximum energy yield from limited rooftop space, without compromising on longevity. These modules utilize **half-cut technology**, which better withstands partial shading and reduces the risk of localized overheating, as well as **multi-busbar (MBB) construction**, improving current conduction and operational stability under real-world conditions. In practice, this translates to more predictable energy production throughout the day, even with poorer weather conditions or dirt on the glass. Another highlight is the **enhanced mechanical durability**, which is crucial in Poland's climate, especially under snow and wind loads. Thanks to the **Full Black aesthetic** (depending on the version), the series is often chosen for single-family homes and buildings with high visual standards. This is an excellent choice for installers and investors who wish to achieve high power density, durability, and a refined appearance - without paying for premium solutions. ## Notable figures - At 19.7% efficiency, this panel is on par with typical \*\*PERC 0-400W\*\* modules - At 197.2 W/m² power density, roof space requirements are typical for \*\*PERC 0-400W\*\* panels - Temperature coefficient of -0.35%/°C matches the \*\*PERC 0-400W\*\* median - At 19.5 kg, weight matches the \*\*PERC 0-400W\*\* median - #12511 for efficiency, #10419 for temperature performance out of 14005 panels ## Questions ### What do half-cut cell technology and MBB mean in the JA Solar JAM54S31 380-405/MR panels, and why does it matter? Half-cut technology splits each PERC cell in two, reducing resistive losses and improving tolerance to partial shading — for example from a chimney or antenna. The multi-busbar design with 11 busbars enhances current collection and lowers the risk of micro-cracks. In practice, this means more consistent and predictable energy output throughout the day, even under diffuse light or overcast conditions. ### What is the warranty on the JA Solar JAM54S31-405/MR panels? The manufacturer offers a 12-year product warranty covering material and workmanship defects. The linear power warranty runs for 25 years with a maximum annual degradation of 0.55%, guaranteeing at least 82.7% of rated output after 25 years of operation. Both warranty tiers are standard for a Tier 1 manufacturer such as JA Solar. ### How does the JA Solar JAM54S31-405/MR perform in winter and low-light conditions? PERC cell technology improves light absorption at low incidence angles typical of fall and winter in Central Europe. The temperature coefficient of -0.35%/°C means panels actually operate more efficiently in cold weather than in summer heat. The 11-busbar MBB construction further stabilizes output under diffuse, overcast conditions and with light soiling on the glass surface. ### Can the JAM54S31 380-405/MR series handle heavy snow loads and strong winds? The JAM54S31 380-405/MR modules are certified for snow loads up to 5,400 Pa and wind loads up to 2,400 Pa, comfortably meeting the demands of Central European climates. Each panel weighs 19.5 kg with dimensions of 1722 x 1134 x 30 mm, making rooftop handling and installation on standard pitched-roof racking systems straightforward. The reinforced aluminum frame ensures long-term structural stability. ### Is the JA Solar JAM54S31 380-405/MR series available in a Full Black version and who is it designed for? Yes, the JAM54S31 380-405/MR series was offered in a Full Black variant featuring black cells, a black frame, and a black backsheet. It is a popular choice for single-family homes and buildings with elevated aesthetic requirements. The electrical specifications are identical to the standard version; the only difference is a slightly higher operating temperature due to the darker surface absorbing more heat. ### Is the JA Solar JAM54S31 380-405/MR series still available for purchase? The JAM54S31 380-405/MR series has been discontinued and is no longer actively distributed by JA Solar. Remaining stock may still be found through distributors or on the secondary market. If you need similar performance with full warranty support, consider newer JA Solar series based on PERC or TOPCon technology, which offer higher power output and current after-sales coverage. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/20230309022600851-d0c73cd825e6.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Gamko New Energy GKA210M340W](https://comparepv.com/panel/gamko-new-energy-gka210m340w) | 340 W | -45 W, +3.3 pp, +5 yr warranty | | [Gamko New Energy GKA210M360W](https://comparepv.com/panel/gamko-new-energy-gka210m360w) | 360 W | Lighter, +3.3 pp, +5 yr warranty | | [Gamko New Energy GKA210M380W (1/4\*4\*38)](https://comparepv.com/panel/gamko-new-energy-gka210m380w-1-4-4-38) | 380 W | Lighter, +3.3 pp, +5 yr warranty | | [Gamko New Energy GKA210M400W (1/2\*4\*20)](https://comparepv.com/panel/gamko-new-energy-gka210m400w-1-2-4-20) | 400 W | +15 W, +3.3 pp, +5 yr warranty | | [Gamko New Energy GKA210M400W (1/4\*4\*40)](https://comparepv.com/panel/gamko-new-energy-gka210m400w-1-4-4-40) | 400 W | +15 W, +3.3 pp, +5 yr warranty | | [Gamko New Energy GKA210M380W (1/2\*4\*19)](https://comparepv.com/panel/gamko-new-energy-gka210m380w-1-2-4-19) | 380 W | Lighter, +3.3 pp, +5 yr warranty | | [Luxor Solar LX-435M/182-108+ GG](https://comparepv.com/panel/luxor-solar-lx-435m-182-108-gg-1) | 435 W | +50 W, cooler, +3.1 pp | | [Jetion JT435SYk(B)](https://comparepv.com/panel/jetion-jt435syk-b) | 435 W | +50 W, cooler, +3.0 pp | | [Maxeon SPR-MAX3-430-R](https://comparepv.com/panel/maxeon-spr-max3-430-r) | 430 W | Cooler, +3.0 pp, +15 yr warranty | | [Luxor Solar LX-435M/182-108+](https://comparepv.com/panel/luxor-solar-lx-435m-182-108) | 435 W | +50 W, cooler, +2.9 pp | | [JA Solar JAM54S31-380/MR](https://comparepv.com/panel/ja-solar-jam54s31-380-mr) | 380 W | Very close match | | [JA Solar JAM54D30-390/MB/1500V](https://comparepv.com/panel/ja-solar-jam54d30-390-mb-1500v) | 390 W | Heavier, +5 yr warranty | | [JA Solar JAM54S31-390/MR](https://comparepv.com/panel/ja-solar-jam54s31-390-mr) | 390 W | +0.3 pp | | [JA Solar JAM54D30-395/MB/1500V](https://comparepv.com/panel/ja-solar-jam54d30-395-mb-1500v) | 395 W | Heavier, +0.5 pp, +5 yr warranty | | [JA Solar JAM54S31-395/MR](https://comparepv.com/panel/ja-solar-jam54s31-395-mr) | 395 W | +10 W, +0.5 pp | | [JA Solar JAM54S30-400/MR](https://comparepv.com/panel/ja-solar-jam54s30-400-mr) | 400 W | +15 W, +0.8 pp | | [Longi Solar LR7-54HJD-510M](https://comparepv.com/panel/longi-lr7-54hjd-510m) | 510 W | +125 W, cooler, +5.3 pp | --- Source: https://comparepv.com/panel/ja-solar-jam54s31-385-mr Not in this file, on the page: a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.