Usable capacity is not a fixed number
The energy a battery can deliver today depends on the condition of its cells and what the facility asks of it.
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The energy a battery can deliver today depends on the condition of its cells and what the facility asks of it.
Cell condition
Facility demand
Operating limit
Rated capacity is not the operating limit.
A battery's rated capacity is a design value. The energy available in operation changes with temperature, aging, power demand and protection limits. A single capacity figure cannot tell a facility what it can rely on at a given moment.
Measurement keeps the limit current.
Cell-level measurement helps locate where change begins. Battery models can carry that information into limits for available energy and power. Those limits need to be tested against measurements and field data.
The decision belongs at facility level.
The battery, grid connection and changing loads are parts of the same facility. The battery's limit must therefore be considered alongside the facility's needs. The architecture Wattality is developing aims to carry cell-level information into those decisions.
- Usable capacity
- Cell-level measurement
- Battery control
