Renogy 640W (2 x 320W) 2-Pack
#30 in 150 W and upFull review
A large-panel pair for a cabin, shed or ground-mount array with a high-voltage MPPT controller. Too big and too high-voltage for most van and small RV setups.
Amazon $599.99$599.99
The Renogy 640W (2 x 320W) 2-Pack is the better rigid solar panel overall, rated 3.9 to 3.8. The Renogy 640W (2 x 320W) 2-Pack leads on efficiency. The DOKIO 800W (2 x 400W) 2-Pack wins on value. The DOKIO 800W (2 x 400W) 2-Pack costs $110.22 less ($489.77 vs $599.99).
DOKIO 800W (2 x 400W) 2-Pack
#36 in 150 W and upFull review
A low-cost way to put 800 W on a shed roof or ground mount with an MPPT controller. Buyers who want a stated warranty and a full spec sheet should pay a little more for a better-documented brand.
Amazon $489.77$489.77
Prices were last checked October 26, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Which should you buy?
- Choose the Renogy 640W (2 x 320W) 2-Pack for efficiency (22.1% module efficiency (from size and rated power) vs 20.5% module efficiency (from size and rated power)).
- Choose the DOKIO 800W (2 x 400W) 2-Pack for value ($0.61 per rated watt vs $0.94 per rated watt).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 150 W and up rigid solar panel; a clear win is highlighted. How we rank explains each one.
| Factor weight | Renogy 640W (2 x 320W) 2-Pack | DOKIO 800W (2 x 400W) 2-Pack |
|---|---|---|
| Overall rating | 3.9/5 | 3.8/5 |
| Value 45% | 54 $0.94 per rated watt | 85 $0.61 per rated watt |
| Tested output 15% | 50 not yet independently tested (neutral score used) | 50 not yet independently tested (neutral score used) |
| Durability 25% | 100 IP68, 10-year warranty | 50 IP rating and warranty not published (neutral score used) |
| Efficiency 15% | 82 22.1% module efficiency (from size and rated power) | 50 20.5% module efficiency (from size and rated power) |
Specifications
| Renogy 640W (2 x 320W) 2-Pack | DOKIO 800W (2 x 400W) 2-Pack | |
|---|---|---|
| Output | ||
| Rated power | 640 W | 800 W |
| Module efficiency | 22.1% (rated power over panel area) | 20.5% (rated power over panel area) |
| Claimed efficiency | 25% (cell efficiency, "up to"; datasheet module efficiency 22.2%) | - |
| Cells | Monocrystalline (N-type, 18BB (per Renogy's product page and Amazon; the datasheet says only monocrystalline, 60 cells)) | Monocrystalline |
| Bifacial | No | No |
| Electrical | ||
| Open-circuit voltage (Voc) | 43.8 V | 37.1 V |
| Voltage at max power (Vmp) | 37.9 V | 31 V |
| Short-circuit current (Isc) | 8.9 A | 13.2 A |
| Current at max power (Imp) | 8.5 A | - |
| Voc temperature coefficient | -0.3%/°C | - |
| Series / parallel | - | Yes |
| Connections | ||
| Output connector | Solar connectors (IP68) | MC4 |
| Build | ||
| Dimensions | 64.6 x 34.7 x 1.4 in (each panel) | 67.8 x 44.6 x 1.2 in (each panel) |
| Frame | anodized aluminum alloy | aluminum |
| Glass | 3.2 mm tempered | tempered |
| Junction box rating | IP68 | - |
| Warranty | 10 years | - |
| Output warranty | 95% output for 5 years, 90% for 10 years, 80% for 25 years | - |
| Released | 2025-09 | - |