Published 2026-10-12 · Figures from EVE Energy published specifications
For the last few years the 280Ah prismatic LFP cell was the default building block for home and commercial storage. The 314Ah generation has now taken over many new designs. Using EVE's own datasheet figures, here is what changes when you move from the LF280K to the MB31.
Same can, more energy
Both cells use the same 173.7 × 71.7 × 207.2 mm aluminium can. That is the main reason 314Ah cells spread so quickly: module frames, busbars and enclosures designed for 280Ah cells can usually be reused.
| Parameter | LF280K | MB31 |
|---|---|---|
| Nominal capacity | 280 Ah | 314 Ah |
| Nominal voltage | 3.20 V | 3.20 V |
| Energy per cell | 896 Wh | 1,004.8 Wh |
| Standard cycles (0.5P/0.5P, 25 °C) | 8000 | 8000 |
| Weight | 5490 ± 300 g | 5600 ± 300 g |
| Energy density | 163 Wh/kg | 179 Wh/kg |
| Dimensions | 173.7 × 71.7 × 207.2 mm | 173.7 × 71.7 × 207.2 mm |
Each MB31 stores about 109 Wh more than an LF280K, roughly 12% more, while weighing about 2% more. Energy density rises from 163 to 179 Wh/kg.
What it means for a 51.2V home battery
A 16-cell series pack (16S, 51.2V nominal) gives:
- LF280K: 16 × 896 Wh = 14.3 kWh
- MB31: 16 × 1,004.8 Wh = 16.1 kWh
The enclosure, BMS cell count and wiring are the same, so the cost per kWh of the finished battery falls. For a 100 kWh C&I cabinet you need about 100 MB31 cells instead of about 112 LF280K cells.
When 280Ah still makes sense
- Certified designs. If your battery is already certified with 280Ah cells, switching cells usually triggers re-testing. Budget for that before you change.
- BMS current limits. At 0.5P the MB31 runs at about 157 A versus 140 A for the LF280K. Check your BMS, fuses and busbars.
- Existing stock and spares. Fleets with 280Ah packs in the field may prefer to keep one cell type for service.
Beyond 314Ah
EVE also lists the MB30 (306Ah, rated 10000 cycles) in the same can, the LF356L at 356.25Ah, and the double-length LF560K (560Ah) for utility systems. If cycle life matters more than capacity, the MB30 is worth comparing.
Bottom line
For new designs, the MB31 gives about 12% more energy in the same footprint with the same rated cycle life. Stay with the LF280K only when re-certification or BMS limits make the switch expensive.
