--- title: "Seraphim SRP-685-BTC-BG vs Seraphim SRP-720-BHC-BG - Solar Panel Comparison | ComparePV" description: "Compare Seraphim SRP-685-BTC-BG vs Seraphim SRP-720-BHC-BG side by side: what actually differs, output when it is hot, thirty-year production, and the full specification." source: "https://comparepv.com/compare/seraphim-srp-685-btc-bg/seraphim-srp-720-bhc-bg" updated: 2026-09-11 --- # Seraphim SRP-685-BTC-BG vs Seraphim SRP-720-BHC-BG 720-BHC-BG leads on the differences that matter The largest is module efficiency: 1.13 pp more efficient. 9 of 19 comparable parameters are identical. ## The two panels | Attribute | A | B | | --- | --- | --- | | Panel | [Seraphim SRP-685-BTC-BG](https://comparepv.com/panel/seraphim-srp-685-btc-bg) | [Seraphim SRP-720-BHC-BG](https://comparepv.com/panel/seraphim-srp-720-bhc-bg) | | Manufacturer | Seraphim | Seraphim | | Power | 685 Wp | 720 Wp | | Efficiency | 22.05 % | 23.18 % | | Technology | TOPCon | HJT | ## Where they differ Ranked by how much the difference matters, not by datasheet order. | Parameter | 685-BTC-BG | 720-BHC-BG | Difference | | --- | --- | --- | --- | | Module efficiency | 22.05 % | 23.18 % | +1.13 pp for 720-BHC-BG | | Temperature coefficient | -0.290 %/°C | -0.258 %/°C | +0.032 %/°C for 720-BHC-BG | | Power density | 220.5 Wp/m² | 231.8 Wp/m² | +11.3 Wp/m² for 720-BHC-BG | | Rated power | 685 Wp | 720 Wp | +35 W for 720-BHC-BG | | Annual degradation | 0.40 %/yr | 0.30 %/yr | -0.10 %/yr for 720-BHC-BG | | Open-circuit voltage | 47.90 V | 50.80 V | 2.90 V apart | | Cell technology | TOPCon | HJT | TOPCon vs HJT | | Weight per kWp | 56.2 kg/kWp | 53.5 kg/kWp | -2.7 kg/kWp for 720-BHC-BG | | Voltage at max power | 39.93 V | 42.78 V | 2.85 V apart | | Short-circuit current | 18.20 A | 17.68 A | 0.52 A apart | ## Every compared parameter | Parameter | 685-BTC-BG | 720-BHC-BG | | --- | --- | --- | | Rated power | 685 Wp | 720 Wp | | Module efficiency | 22.05 % | 23.18 % | | Power density | 220.5 Wp/m² | 231.8 Wp/m² | | Open-circuit voltage | 47.90 V | 50.80 V | | Voltage at max power | 39.93 V | 42.78 V | | Short-circuit current | 18.20 A | 17.68 A | | Current at max power | 17.16 A | 16.88 A | | Temperature coefficient | -0.290 %/°C | -0.258 %/°C | | Dimensions | 2384x1303x33 mm | 2384x1303x33 mm | | Module area | 3.106 m² | 3.106 m² | | Weight | 38.5 kg | 38.5 kg | | Weight per kWp | 56.2 kg/kWp | 53.5 kg/kWp | | Product warranty | 15 yrs | 15 yrs | | Performance warranty | 30 yrs | 30 yrs | | Annual degradation | 0.40 %/yr | 0.30 %/yr | | Cell technology | TOPCon | HJT | | Cell type | Monocrystalline | Monocrystalline | | Cell count | 132 | 132 | | Bifacial | Yes | Yes | ## Thirty-year yield Each panel's own declared degradation curve, at 1,200 kWh/kWp a year - **Cumulative output, 685-BTC-BG:** 22,983 kWh - **Cumulative output, 720-BHC-BG:** 24,533 kWh - **Gap:** 1,550 kWh ## Output when hot | Condition | Cell temperature | 685-BTC-BG | 720-BHC-BG | Retained | | --- | --- | --- | --- | --- | | Standard test conditions | 25 °C | 685 W | 720 W | 100.0% of rated power | | Cool, bright day | 40 °C | 655 W | 692 W | 95.7% of rated power | | Typical summer roof | 55 °C | 625 W | 664 W | 91.3% of rated power | | Hot roof | 70 °C | 596 W | 636 W | 87.0% of rated power | ## Against the whole database | Measure | 685-BTC-BG | 720-BHC-BG | Out of | Note | | --- | --- | --- | --- | --- | | Efficiency | #6,233 | #1,424 | 14,005 | 720-BHC-BG leads by 4,809 places | | Power density | #6,208 | #1,347 | 14,005 | 720-BHC-BG leads by 4,861 places | | Heat behaviour | #2,165 | #466 | 14,005 | 720-BHC-BG leads by 1,699 places | | Weight | #10,487 | #7,424 | 14,005 | 720-BHC-BG leads by 3,063 places | | Warranty | #21 | #21 | 14,005 | Tied - the same position in the database | | Overall | #1,444 | #362 | 14,005 | 720-BHC-BG leads by 1,082 places | ## Questions ### Which panel is better: Seraphim SRP-685-BTC-BG or Seraphim SRP-720-BHC-BG? According to our database: **Seraphim SRP-720-BHC-BG** has higher module efficiency (**23.18%** vs **22.05%**); **Seraphim SRP-720-BHC-BG** tolerates heat better (temp coeff **-0.258%/°C** vs **-0.290%/°C**). See the full spec comparison and 30-year energy simulation above for a complete picture. ### What is the efficiency of Seraphim SRP-685-BTC-BG and Seraphim SRP-720-BHC-BG? **Seraphim SRP-685-BTC-BG** has a module efficiency of **22.05%**, while **Seraphim SRP-720-BHC-BG** is **23.18%**. Higher efficiency means more electricity from the same roof area - useful when space is limited. ### What cell technology does Seraphim SRP-685-BTC-BG use vs Seraphim SRP-720-BHC-BG? **Seraphim SRP-685-BTC-BG** uses **TOPCon** cells; **Seraphim SRP-720-BHC-BG** uses **HJT**. 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 Seraphim SRP-685-BTC-BG and Seraphim SRP-720-BHC-BG? **Seraphim SRP-685-BTC-BG** has a **30 years** power warranty; **Seraphim SRP-720-BHC-BG** has a **30 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. ### Are Seraphim SRP-685-BTC-BG and Seraphim SRP-720-BHC-BG bifacial panels? Both **Seraphim SRP-685-BTC-BG** and **Seraphim SRP-720-BHC-BG** are bifacial - they capture reflected light from the ground, which can add 5**-15%** more annual energy on ground-mount or elevated rooftop installations with a light surface beneath. ## Related comparisons - [Seraphim SRP-685-BTC-BG vs Seraphim SRP-690-BTC-BG](https://comparepv.com/compare/seraphim-srp-685-btc-bg/seraphim-srp-690-btc-bg) - The same specification on paper - [Seraphim SRP-720-BHC-BG vs Seraphim SRP-730-BHC-BG](https://comparepv.com/compare/seraphim-srp-720-bhc-bg/seraphim-srp-730-bhc-bg) - 3 differences, the largest is module efficiency - [Seraphim SRP-720-BHC-BG vs Seraphim SRP-725-BHC-BG](https://comparepv.com/compare/seraphim-srp-720-bhc-bg/seraphim-srp-725-bhc-bg) - The same specification on paper - [Seraphim SRP-720-BHC-BG vs Seraphim SRP-715-BHC-BG](https://comparepv.com/compare/seraphim-srp-720-bhc-bg/seraphim-srp-715-bhc-bg) - The same specification on paper - [Seraphim SRP-720-BHC-BG vs Seraphim SRP-710-BHC-BG](https://comparepv.com/compare/seraphim-srp-720-bhc-bg/seraphim-srp-710-bhc-bg) - 3 differences, the largest is module efficiency - [Seraphim SRP-720-BHC-BG vs Seraphim SRP-705-BHC-BG](https://comparepv.com/compare/seraphim-srp-720-bhc-bg/seraphim-srp-705-bhc-bg) - 3 differences, the largest is module efficiency --- Source: https://comparepv.com/compare/seraphim-srp-685-btc-bg/seraphim-srp-720-bhc-bg Not in this file, on the page: the thirty-year yield curve year by year at a cell temperature you pick and a written summary generated on request.