Energy storage, simplified.
William is a modular home battery designed in New Zealand for reliable, scalable energy storage. Start at 16 kWh and expand up to 80 kWh as your energy needs grow — cleanly, safely, and without replacing your system.
From $7,500 incl. GST
Power That Scales
Built to grow with you.
Add capacity by stacking identical modules. No oversized systems up front, no costly replacements later — just expand when you need more energy.
Smarter Inside
Designed for long life.
Active cell balancing helps maintain consistent performance across thousands of cycles, maximising usable capacity over the life of the system.
Engineered AND ASSEMBLED in New Zealand
Designed and assembled locally, William is built for reliability, serviceability, and real-world conditions — not disposable consumer electronics.
Specifications
| Specification | William Core | Core + Expansion | Core + 2× Expansion | Core + 3× Expansion | Core + 4× Expansion |
|---|---|---|---|---|---|
| Product Specification | 51.2V / 314Ah | 51.2V / 628Ah | 51.2V / 942Ah | 51.2V / 1256Ah | 51.2V / 1570Ah |
| Nominal Voltage | 51.2V | 51.2V | 51.2V | 51.2V | 51.2V |
| Nominal Capacity | 314Ah | 628Ah | 942Ah | 1256Ah | 1570Ah |
| Battery Energy | 16.07kWh | 32.14kWh | 48.21kWh | 64.28kWh | 80.35kWh |
| Max Charge Current | 150A | 250A* | 250A* | 250A* | 250A* |
| Max Discharge Current | 150A | 250A* | 250A* | 250A* | 250A* |
| Recommended Load | ~5–7kW | ~5–13kW* | ~5–13kW* | ~5–13kW* | ~5–13kW* |
| Charging Cut-off Voltage | 57.6V ±0.2V | 57.6V ±0.2V | 57.6V ±0.2V | 57.6V ±0.2V | 57.6V ±0.2V |
| Discharging Cut-off Voltage | 44.8V ±0.2V | 44.8V ±0.2V | 44.8V ±0.2V | 44.8V ±0.2V | 44.8V ±0.2V |
| Cell Type | LiFePO₄ Grade A | LiFePO₄ Grade A | LiFePO₄ Grade A | LiFePO₄ Grade A | LiFePO₄ Grade A |
| Case Material | Aluminium | Aluminium | Aluminium | Aluminium | Aluminium |
| Colour | Dark Teal | Dark Teal | Dark Teal | Dark Teal | Dark Teal |
| Terminal | M8 | M8 | M8 | M8 | M8 |
| Communication | RS-485 / CAN | RS-485 / CAN | RS-485 / CAN | RS-485 / CAN | RS-485 / CAN |
| Cycle Life | ≥8000 cycles | ≥8000 cycles | ≥8000 cycles | ≥8000 cycles | ≥8000 cycles |
| Warranty | 10 years | 10 years | 10 years | 10 years | 10 years |
| Weight | 112kg | 220kg | 330kg | 440kg | 550kg |
| Dimensions (L×W×H) | 670×480×330mm | 670×480×570mm | 670×480×810mm | 670×480×1060mm | 670×480×1320mm |
| Assembly Method | Stackable & Moveable | Stackable & Moveable | Stackable & Moveable | Stackable & Moveable | Stackable & Moveable |
| Certifications | IEC62619:2022, UN38.3 | IEC62619:2022, UN38.3 | IEC62619:2022, UN38.3 | IEC62619:2022, UN38.3 | IEC62619:2022, UN38.3 |
