Battery pack size versus application is an interesting comparison.
- iWatch ~1Wh
- Mobile ~ 10Wh
- Tablet ~30Wh
- Laptop ~50Wh
- eBike ~500Wh
- Home PV storage ~10kWh
- Electric Car ~100kWh
- Electric Lorry ~500kWh

The plot is based on real data from real products in the market and shows total battery pack size.

The Y-axis is a logarithmic scale and hence the eLorry battery is nearly 6 orders of magnitude, or 1 million times, bigger than the smart watch battery.

Pack Sizing
The usable energy (kWh) of the pack is fundamentally determined by:
- Number of cells in series (S count)
- Number of cells in parallel (P count)
- Capacity of a single cell (Ah)
- Nominal voltage of a single cell (Vnom)
- Usable SoC window (%)
Energy (kWh) = S x P x Ah x Vnom x SoCusable / 1000