FactRatedMost Energy-Efficient Smartphones by Official Energy Class
A smartphone's energy-efficiency class is not simply a battery-life ranking. The official A–G class is based on an Energy Efficiency Index that relates standardized battery endurance to battery energy. A phone can therefore have the longest runtime without necessarily having the strongest efficiency result.
FactRated orders/groups current smartphones by their registered energy class from A to G. If the canonical numeric EEI is not available in the normalized API data, the site does not invent a more precise efficiency order inside the same letter class.
Eligible models: 1,057 · Excluded because the ranking metric is unavailable: 0
Order: Energy efficiency class — official class, A to G. Tied values share the same position. The displayed top percentage includes every model tied at that value. At least 30 comparable models are required for contextual positions.
1,057 results
| # | Model identifier | Energy efficiency class | Battery endurance | Battery cycles | Repairability index | Compare |
|---|---|---|---|---|---|---|
| 1 |  FOSSIBOT F114F114 | A | 57 h 47 min | ≥ 1,000 cycles | 3.16 | |
| 1 | FOSSIBOT F115 UItraF115 UItra | A | 54 h 46 min | ≥ 1,000 cycles | 3.16 | |
| 1 | FOSSIBOT F116 ProF116 Pro | A | 40 h | ≥ 1,000 cycles | 2.97 | |
| 1 | FUFFI M106S24PROM106S24PRO | A | 8 h | ≥ 1,000 cycles | 3.65 | |
| 1 | FUFFI M17 ProM17 Pro | A | 9 h 20 min | ≥ 1,000 cycles | 2.44 | |
| 1 | FUFFI S24 ProS24 Pro | A | 11 h | ≥ 3,000 cycles | 2.54 | |
| 1 | FUFFI S26 ProS26 Pro | A | 11 h | ≥ 3,000 cycles | 2.54 | |
| 1 | Gigaset GS6 PRO-2GS6 PRO-2 | A | 55 h | ≥ 1,000 cycles | 4.24 | |
| 1 | Gigaset GS6-2GS6-2 | A | 55 h | ≥ 1,000 cycles | 4.24 | |
| 1 | Gigaset GX30GX30 | A | 59 h 57 min | ≥ 1,000 cycles | 3.85 | |
| 1 | Google G4H7LG4H7L | A | 53 h 14 min | ≥ 1,000 cycles | 3.84 | |
| 1 | Google GEHN3GEHN3 | A | 51 h 9 min | ≥ 1,000 cycles | 3.67 | |
| 1 | HAMMER BLADE Va 5GBLADE Va 5G | A | 73 h 13 min | ≥ 1,000 cycles | 3.39 | |
| 1 | HAMMER CONSTRUCTION 2 5GCONSTRUCTION 2 5G | A | 69 h 30 min | ≥ 1,000 cycles | 3.47 | |
| 1 | HAMMER CONSTRUCTION 2 THERMAL 5GCONSTRUCTION 2 THERMAL 5G | A | 69 h 30 min | ≥ 1,000 cycles | 3.47 | |
| 1 | HAMMER ENERGY X2ENERGY X2 | A | 59 h 35 min | ≥ 1,000 cycles | 3.32 | |
| 1 | HAMMER ENERGY X2 5GENERGY X2 5G | A | 60 h 26 min | ≥ 1,000 cycles | 3.32 | |
| 1 | HAMMER IRON 6IRON 6 | A | 81 h 30 min | ≥ 1,000 cycles | 2.9 | |
| 1 | HAMMER IRON 6 5GIRON 6 5G | A | 81 h 30 min | ≥ 1,000 cycles | 3.47 | |
| 1 | HAMMER RANGERRANGER | A | 70 h 56 min | ≥ 1,000 cycles | 3.62 | |
| 1 | HAMMER Ventus 5GVentus 5G | A | 51 h 55 min | ≥ 1,000 cycles | 3.85 | |
| 1 | HMD TA-1588TA-1588 | A | 62 h | ≥ 800 cycles | 3.93 | |
| 1 | HMD TA-1589TA-1589 | A | 60 h | ≥ 800 cycles | 3.93 | |
| 1 | HMD TA-1600TA-1600 | A | 48 h 30 min | ≥ 800 cycles | 4.01 | |
| 1 | HMD TA-1640TA-1640 | A | 61 h 13 min | ≥ 800 cycles | 4.02 |
Data source: EPREL · Last updated: Sep 7, 2026
How this page works
The primary comparison is the official energy class. Models in class A appear before B, then C through G. Within a class, FactRated may use a clearly labelled secondary sort such as battery endurance for usability, but that secondary order must not be described as a more precise energy-efficiency ranking.
Battery capacity, cycle durability and repairability appear as context because efficiency is only one part of product choice.
Energy class vs battery runtime
Runtime asks how long a full charge lasts under the standardized workload. Efficiency asks how effectively the device obtains that runtime from the battery energy used in the calculation.
That is why comparing only mAh or only hours can miss part of the picture.
Smartphones and slate tablets also use different EEI class thresholds, so FactRated keeps their energy-class pages separate.
Frequently asked questions
Is class A always the phone with the longest battery life?
No. Class A is the highest energy-efficiency class; absolute standardized runtime is a different measurement.
Does a larger battery automatically improve the energy class?
No. The efficiency calculation relates runtime to battery energy, so simply increasing capacity does not guarantee a better class.
Can FactRated rank two class-A phones by efficiency?
Only if a canonical numeric efficiency value is available to support that order. In beta, FactRated does not create extra precision from unrelated fields.
Can I compare smartphone and tablet energy classes in one ranking?
Not as one common numeric ladder. The class thresholds differ between the two device types, so FactRated keeps their ranking cohorts separate.
Related FactRated pages
- Smartphone energy-efficiency classes explained
- Longest standardized battery endurance
- Filter by energy class
Data source: EPREL · Last updated: Sep 7, 2026
Data source: EPREL · Last updated: Sep 7, 2026