LONGi Hi-MO X6 Max 470W vs Hyundai HiE-S420VG
The Hyundai HiE-S420VG wins this comparison by a clear margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Key Differences
- • LONGi Hi-MO X6 Max 470W is rated at 470W while Hyundai HiE-S420VG is rated at 420W, a 50W difference.
- • LONGi Hi-MO X6 Max 470W achieves 22.3% efficiency vs 21.5% for the other, a 0.8 percentage point gap.
- • Hyundai HiE-S420VG comes with a 25-year product warranty vs 15 years for the other.
- • LONGi Hi-MO X6 Max 470W has a superior temperature coefficient of -0.29%/°C vs -0.3%/°C, retaining more power in hot climates.
Specifications Breakdown
Module Efficiency
The LONGi Hi-MO X6 Max 470W achieves 22.3% module efficiency compared to Hyundai HiE-S420VG's 21.5%, meaning LONGi Hi-MO X6 Max 470W converts 0.8 percentage points more sunlight into electricity per square meter. In practical terms, the LONGi Hi-MO X6 Max 470W produces 235.2 watts per square meter of panel area while the Hyundai HiE-S420VG produces 215.1 W/m². For rooftop installations where space is limited, this efficiency gap determines how many kilowatts you can fit on your available roof area. Over a 25-year system life, even a small efficiency advantage compounds into meaningful additional energy production.
Power Output
The LONGi Hi-MO X6 Max 470W delivers 470W per panel versus 420W for the Hyundai HiE-S420VG, a 50W difference per module. To build an 8 kW residential system, you would need 18 LONGi Hi-MO X6 Max 470W panels or 20 Hyundai HiE-S420VG panels. Choosing the higher-wattage option saves 2 panels, reducing total racking hardware, wiring, and installation labor costs. Higher wattage per panel is particularly valuable for commercial-scale installations where panel count directly impacts balance-of-system costs.
Temperature Coefficient
The LONGi Hi-MO X6 Max 470W has a temperature coefficient of -0.29%/°C versus -0.3%/°C for the Hyundai HiE-S420VG. On a hot summer day when cell temperature reaches 65°C (40°C above the 25°C STC baseline), the LONGi Hi-MO X6 Max 470W retains 94.2% of its rated power while the other retains 94.0%. While the numerical gap is modest, it still accumulates over decades of summer production, especially in southern latitudes with prolonged peak heat hours.
Warranty Coverage
The LONGi Hi-MO X6 Max 470W is backed by a 15-year product warranty and 30-year performance guarantee, while the Hyundai HiE-S420VG offers 25-year product and 25-year performance coverage. The Hyundai HiE-S420VG provides 10 additional years of defect protection, covering manufacturing issues, material failures, and premature performance loss. Based on their published degradation rates (1% first year then 0.4%/year for LONGi Hi-MO X6 Max 470W; 1% first year then 0.4%/year for Hyundai HiE-S420VG), after 25 years the LONGi Hi-MO X6 Max 470W should retain approximately 89.4% of original output versus 89.4% for the Hyundai HiE-S420VG. The end-of-life output levels are closely matched.
Physical Dimensions & Weight
The LONGi Hi-MO X6 Max 470W measures 1762×1134×30mm and weighs 23.5 kg, while the Hyundai HiE-S420VG measures 1722×1134×30mm at 21 kg. 2.00 m² of panel area for the LONGi Hi-MO X6 Max 470W versus 1.95 m² for the Hyundai HiE-S420VG. The Hyundai HiE-S420VG is 2.5 kg lighter per panel, which reduces structural load requirements on the roof and makes handling easier during installation. For a 20-panel system, that is a total weight difference of 50 kg. Similar footprints mean both panels fit comparably on standard residential rooftop configurations.
Specification Comparison
| Specification | LONGi Hi-MO X6 Max 470W | Hyundai HiE-S420VG |
|---|---|---|
| Power | 470W | 420W |
| Efficiency | 22.3% | 21.5% |
| Power Density | 21.9 W/sq ft | 20.0 W/sq ft |
| Cell Type | TOPCon N-type | TOPCon N-type |
| Bifacial | Yes | No |
| Weight | 23.5 kg | 21 kg |
| Temp Coefficient | -0.29%/°C | -0.3%/°C |
| Snow Load | 5400 Pa | 5400 Pa |
| Wind Load | 2400 Pa | 2400 Pa |
| Product Warranty | 15 years | 25 years |
| Performance Warranty | 30 years | 25 years |
| Degradation (Year 1) | 1% | 1% |
| Annual Degradation | 0.4% | 0.4% |
| Country | China | South Korea |
5-Dimension Head-to-Head Analysis
1. Efficiency & Power Density
Winner: LONGi Hi-MO X6 Max 470WThe LONGi Hi-MO X6 Max 470W achieves 22.3% efficiency versus 21.5% — a 0.8 percentage point advantage. On a typical 30-panel residential roof, this translates to approximately 1.5 kW more total system capacity, or 7 kWh more annual production in an average US location.
2. Hot Climate Performance
Winner: LONGi Hi-MO X6 Max 470WThe LONGi Hi-MO X6 Max 470W has a better temperature coefficient of -0.29%/°C versus -0.3%/°C. On a 45°C summer day (20°C above STC), the winner retains 94.2% of rated power versus 94.0%. The difference is modest but accumulates over 25 years of summer production.
3. Durability & Warranty
Winner: Hyundai HiE-S420VGHyundai HiE-S420VG leads with a 25-year product warranty versus 15 years. After 25 years, expect 89.4% vs 89.4% of original output for LONGi Hi-MO X6 Max 470W and Hyundai HiE-S420VG respectively.
4. Power Output
Winner: LONGi Hi-MO X6 Max 470WThe LONGi Hi-MO X6 Max 470W delivers 470W versus 420W per panel — 50W more. For an 8 kW system, you need 18 panels with the higher-wattage option versus 20 panels, saving 2 panels and the associated racking and labor costs.
5. Cell Technology
Winner: TieBoth panels use TOPCon N-type cell technology. No technology advantage for either product.
LONGi Hi-MO X6 Max 470W
The Hi-MO X6 Max delivers 470W in a mid-size format with N-type TOPCon technology, bridging the gap between compact and large panels.
Pros
- + Mid-size versatility
- + N-type TOPCon efficiency
- + Good power-to-size ratio
- + LONGi reliability
Cons
- - Mid-range pricing
- - Not the highest output
- - Standard warranty
Hyundai HiE-S420VG
The Hyundai HiE-S420VG is a 420W residential-format TOPCon N-type panel in the popular 108-cell configuration (1722 x 1134mm), matching the most common residential panel size for easy racking and roof fit. Korean manufacturing provides supply chain diversification, and the TOPCon N-type cells deliver better temperature performance (-0.30%/°C) and lower degradation than PERC alternatives. The standard residential form factor ensures compatibility with all major racking systems.
Pros
- + Standard 108-cell residential size — fits any racking system
- + Korean-made TOPCon N-type with 21.5% efficiency
- + -0.30%/°C temperature coefficient for hot climate performance
- + 25+25 year warranty backed by Hyundai corporate
- + Non-Chinese manufacturing for tariff and UFLPA considerations
- + 420W competitive output in standard residential format
Cons
- - 420W is competitive but not class-leading for 108-cell panels
- - Slightly higher per-watt cost than Chinese equivalents
- - Smaller US installer network and distribution
- - Less brand recognition in solar market despite Hyundai name
Choose LONGi Hi-MO X6 Max 470W If...
- ✓ Your roof space is limited and you need maximum power per panel
- ✓ You want fewer panels to reach your target system size, reducing racking and labor costs
- ✓ You live in a hot climate (Arizona, Texas, Florida) where heat performance matters
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Medium-sized residential roofs wanting a balance of size and N-type performance.
Choose Hyundai HiE-S420VG If...
- ✓ Long-term warranty protection is a top priority and you plan to stay in your home for 25+ years
- ✓ You prefer newer cell technology with a longer performance improvement runway
- ✓ Residential homeowners wanting a standard-size Korean-manufactured TOPCon panel that fits any roof and racking system with strong corporate warranty backing.
Our Recommendation
We recommend the Hyundai HiE-S420VG for most buyers in this comparison. It wins 1 of 5 key dimensions and offers a clear advantage in the metrics that matter most for a solar panel purchase. The LONGi Hi-MO X6 Max 470W remains a good product, but the Hyundai HiE-S420VG delivers better overall value for the majority of installations.
Frequently Asked Questions
Which is better, LONGi Hi-MO X6 Max 470W or Hyundai HiE-S420VG?
The Hyundai HiE-S420VG wins this comparison by a clear margin. It offers better long-term durability with 25-year warranty. For most residential installations, the Hyundai HiE-S420VG is the stronger choice.
Which panel is more efficient, LONGi Hi-MO X6 Max 470W or Hyundai HiE-S420VG?
The LONGi Hi-MO X6 Max 470W at 22.3% module efficiency. Higher efficiency means more watts per square foot of roof space, which is critical for space-constrained installations. The difference of 0.8 percentage points translates to approximately 50W per panel under standard test conditions.
Which has a better warranty, LONGi Hi-MO X6 Max 470W or Hyundai HiE-S420VG?
The LONGi Hi-MO X6 Max 470W comes with a 15-year product warranty and 30-year performance guarantee. The Hyundai HiE-S420VG offers 25-year product and 25-year performance warranties. Hyundai HiE-S420VG provides 10 additional years of product coverage.
Which panel performs better in hot weather?
The LONGi Hi-MO X6 Max 470W has a temperature coefficient of -0.29%/°C and the Hyundai HiE-S420VG is -0.3%/°C. LONGi Hi-MO X6 Max 470W retains more power in heat — important in states like Arizona, Texas, and Florida. A lower (less negative) temperature coefficient is better.
How many LONGi Hi-MO X6 Max 470W vs Hyundai HiE-S420VG panels do I need for an 8 kW system?
For an 8 kW system: you need 18 LONGi Hi-MO X6 Max 470W panels (470W each) or 20 Hyundai HiE-S420VG panels (420W each). The LONGi Hi-MO X6 Max 470W requires fewer panels, saving on racking hardware and installation labor.
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Last updated: February 2026