LONGi Hi-MO 7 vs Hi-MO 9: LR8-66HGD 620W or LR8-66HYD 630W
LR8-66HGD and LR8-66HYD are one letter apart, and buyers type both codes into search. They are two LONGi series in the same 66-cell frame: the Hi-MO 7 LR8-66HGD, read here at 620 W, and the Hi-MO 9 LR8-66HYD, read here at 630 W — one rating step from each other. This page sets the two product records side by side. Both measure 2382×1134×30 mm, both take a 35 A series fuse and both are rated for a 1500 V system, so one replaces the other on the same structure. The differences are finer: 23.3% module efficiency against 23%, a temperature coefficient of -0.26%/°C against -0.28%/°C, a higher short-circuit current on the Hi-MO 9, and two records that describe two different sites.
Specifications side by side
Every figure in this table is read from the product’s own record — the same rows each product page shows.
| Specification | LONGi Hi-MO 7 LR8-66HGD 620W | LONGi Hi-MO 9 LR8-66HYD 630W |
|---|---|---|
| Maximum Power (Pmax) | 620 W | 630 W |
| Open Circuit Voltage (Voc) | 48.8 V | 49.32 V |
| Module Efficiency | 23 % | 23.3 % |
| Temperature Coefficient of Pmax | -0.28 % | -0.26 % |
| Short Circuit Current (Isc) | 15.18 A | 16.22 A |
| Voltage at Maximum Power (Vmpp) | 40.1 V | 40.58 V |
| Current at Maximum Power (Impp) | 15.17 A | 15.53 A |
| Temperature Coefficient of Isc | 0.049 % | 0.05 % |
| Temperature Coefficient of Voc | -0.23 % | -0.2 % |
| Maximum System Voltage | 1500 V | 1500 V |
| Maximum Series Fuse Rating | 35 A | 35 A |
| Dimensions (W×H×D) | 2382×1134×30 mm | 2382×1134×30 mm |
| Weight | 32.5 kg | 33.5 kg |
| Frame Material | Anodized aluminum alloy | Weather-resistant anodized aluminum frame |
| Glass | Dual glass, 2.0+2.0mm heat strengthened glass | Dual glass, weather-resistant semi-tempered glass |
| Front Side Maximum Static Loading | 5400 Pa | 5400 Pa |
| Rear Side Maximum Static Loading | 2400 Pa | 2400 Pa |
| Operating Temperature | -40 ~ 85 °C | -40 ~ 85 °C |
| Warranty | 12 Years Product, 30 Years Performance | 12 Years Product, 30 Years Performance |
| Price | AED 385 | AED 391 |
One Frame, Two Series
The Hi-MO 7 LR8-66HGD record and the Hi-MO 9 LR8-66HYD record state the same dimensions, 2382×1134×30 mm, the same static loads of 5400 Pa front and 2400 Pa rear, the same operating range of -40 to 85 °C and the same warranty: 12 years on the product, 30 years on performance. The Hi-MO 7 weighs 32.5 kg and the Hi-MO 9 weighs 33.5 kg. Both are dual-glass: the Hi-MO 7 record states 2.0+2.0 mm heat strengthened glass in an anodized aluminum alloy frame, the Hi-MO 9 record a weather-resistant semi-tempered dual glass in a weather-resistant anodized aluminum frame. A mounting design drawn for one fits the other.
Efficiency, Voltage and Current
Hi-MO 7 LR8-66HGD at 620 W: 23% module efficiency, a Voc of 48.8 V, a Vmp of 40.1 V, an Isc of 15.18 A and an Imp of 15.17 A. Hi-MO 9 LR8-66HYD at 630 W: 23.3% module efficiency, a Voc of 49.32 V, a Vmp of 40.58 V, an Isc of 16.22 A and an Imp of 15.53 A. The voltages are close enough that string length is planned the same way. The current is where to look: the Hi-MO 9 states an Isc of 16.22 A, so the inverter's maximum input current per MPPT needs to cover it. The maximum series fuse rating is 35 A on both records.
Heat and Bifaciality
The temperature coefficient of Pmax is -0.28%/°C on the Hi-MO 7 record and -0.26%/°C on the Hi-MO 9 record; the coefficient of Voc is -0.23%/°C against -0.2%/°C. In both rows the Hi-MO 9 moves less with temperature. The Hi-MO 7 record states a bifaciality of 80% and describes high bifaciality with an excellent power temperature coefficient, on HPDC cell technology. The Hi-MO 9 record at this rating carries no bifaciality row; it describes BC-cell technology for a lower operating temperature. If rear-side gain over a reflective surface is part of the design, the Hi-MO 7 is the record that states the figure to design with.
Which One for Which Site
The two records name their sites. The Hi-MO 7 LR8-66HGD is described as a high-performance module for utility power plants: ground-mounted rows where its stated 80% bifaciality has a surface to work with. The Hi-MO 9 LR8-66HYD is described as suitable for high-corrosion scenarios such as offshore areas, with a humidity-resistant junction box and connector, dual-layer coated glass and a special aluminum frame for salt corrosion resistance: the coastal roof, the port, the humid site. Both are priced on this site by the same rule of USD 0.169 per watt, so the choice is the site and the inverter's input current, not the budget.
The models in this comparison
LONGi Hi-MO 7 LR8-66HGD 620W
AED 385
LONGi Hi-MO 9 LR8-66HYD 630W
AED 391
Winner
Hi-MO 9 LR8-66HYD for coastal, humid and hot sites; Hi-MO 7 LR8-66HGD for ground-mounted plants that use its stated 80% bifaciality. Same 2382×1134×30 mm frame on both.
Conclusion
Hi-MO 7 and Hi-MO 9 in the 66-cell frame are a close call on the numbers and a clear call on the site. At one rating step apart, the Hi-MO 9 LR8-66HYD states 23.3% efficiency and -0.26%/°C, the Hi-MO 7 LR8-66HGD 23% and -0.28%/°C; the frame, the loads and the warranty are the same. The Hi-MO 9 record is written for salt and humidity and pushes an Isc of 16.22 A; the Hi-MO 7 record is written for utility plants and states a bifaciality of 80%. Match the record to the site, check the inverter's input current, and either panel drops onto the same structure.