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385/MR vs 390/MR 18 of 19 identical Swap Change panels

JA Solar JAM54S31-385/MR vs JA Solar JAM54S31-390/MR

JA Solar JAM54S31-385/MR
JAM54S31-385/MR
385 Wp 19.70 % PERC
Open panel page Datasheet PDF
VS
JA Solar JAM54S31-390/MR
JAM54S31-390/MR
390 Wp 20.00 % PERC
Open panel page Datasheet PDF
The verdict

390/MR leads on the differences that matter

The largest is module efficiency: 0.30 pp more efficient. 18 of 19 comparable parameters are identical.

See the one difference
How alike are they
18 of 19 comparable
parameters are identical
identical differs
01

What actually differs

1 of 19 parameters
Parameter 385/MR 390/MR Difference
Module efficiency 19.70 % 20.00 % 0.30 pp more efficient
02

What it means on a roof

Thirty years of production
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.
385/MR
12,477 kWh
390/MR
12,640 kWh
Lifetime gap
163 kWh
Output when it is hot
Rated power carried across the range a module actually sees
Scenario 385/MR 390/MR
Standard test conditions 25 °C 100.0% of rated power 385 W 390 W
Cool, bright day 40 °C 94.8% of rated power 365 W 370 W
Typical summer roof 55 °C 89.5% of rated power 345 W 349 W
Hot roof 70 °C 84.2% of rated power 324 W 329 W
03

Full specification

Parameter 385/MR 390/MR Difference
Power and efficiency
Rated power 385 Wp 390 Wp Effectively the same
Module efficiency 19.70 % 20.00 % +0.30 pp for 390/MR
Power density 197.2 Wp/m² 199.7 Wp/m² Effectively the same
Open-circuit voltage 36.71 V 36.85 V Effectively the same
Voltage at max power 30.46 V 30.64 V Effectively the same
Short-circuit current 13.52 A 13.61 A Effectively the same
Current at max power 12.64 A 12.73 A Effectively the same
Temperature
Temperature coefficient -0.350 %/°C -0.350 %/°C Same
Mechanical
Dimensions 1722x1134x30 mm 1722x1134x30 mm Same
Module area 1.953 m² 1.953 m² Same
Weight 19.5 kg 19.5 kg Same
Weight per kWp 50.6 kg/kWp 50.0 kg/kWp Effectively the same
Warranty and degradation
Product warranty 12 yrs 12 yrs Same
Performance warranty 25 yrs 25 yrs Same
Annual degradation 0.55 %/yr 0.55 %/yr Same
Technology
Cell technology PERC PERC Same
Cell type Monocrystalline Monocrystalline Same
Cell count 108 108 Same
Bifacial No No Same
04

Against the whole database

14,005 panels
Efficiency
#12,511 vs #12,214
390/MR leads by 297 places
Power density
#12,493 vs #12,255
390/MR leads by 238 places
Heat behaviour
#10,419 vs #10,419
Tied - the same position in the database
Weight
#4,091 vs #3,317
390/MR leads by 774 places
Warranty
#9,798 vs #9,798
Tied - the same position in the database
Overall
#12,528 vs #12,390
390/MR leads by 138 places
05

More useful comparisons

Open the full database
Same series, other bin
JA Solar JAM54S31-385/MR vs JA Solar JAM54S31-405/MR
4 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S31-385/MR vs JA Solar JAM54S31-400/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S31-385/MR vs JA Solar JAM54S31-395/MR
3 differences, the largest is module efficiency
Same series, other bin
JA Solar JAM54S31-385/MR vs JA Solar JAM54S31-380/MR
One difference: module efficiency
Same manufacturer
JA Solar JAM54S31-385/MR vs JA Solar JAM66D46-740/LB
16 differences, the largest is module efficiency
Same manufacturer
JA Solar JAM54S31-385/MR vs JA Solar JAM66D46-735/LB
16 differences, the largest is module efficiency
06

Written summary

07

Questions about this pairing

Which panel is better: JA Solar JAM54S31-385/MR or JA Solar JAM54S31-390/MR?
According to our database: JA Solar JAM54S31-390/MR has higher module efficiency (20.00% vs 19.70%). See the full spec comparison and 30-year energy simulation above for a complete picture.
What is the efficiency of JA Solar JAM54S31-385/MR and JA Solar JAM54S31-390/MR?
JA Solar JAM54S31-385/MR has a module efficiency of 19.70%, while JA Solar JAM54S31-390/MR is 20.00%. Higher efficiency means more electricity from the same roof area - useful when space is limited.
What cell technology does JA Solar JAM54S31-385/MR use vs JA Solar JAM54S31-390/MR?
JA Solar JAM54S31-385/MR uses PERC cells; JA Solar JAM54S31-390/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 JAM54S31-385/MR and JA Solar JAM54S31-390/MR?
JA Solar JAM54S31-385/MR has a 25 years power warranty; JA Solar JAM54S31-390/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.

Shop prices: See 389 JA Solar offers

Every figure here is from the manufacturers' own datasheets - a dash means the value is not published, never an estimate. The thirty-year projection and the temperature scenarios are calculations from those figures, and each states its assumption above.