Cell Design and Materials

Battery Performance Metrics: Definitions and Applications (1/2) Performance Metric

Definition

Improvements Enable

Gravimetric Energy Wh/kg:

The energy provided by the cell divided by its total mass

Enables applications where weight is sensitive (EVTOL, Drone, Wearables, Infantry gear)

Volumetric Energy Wh/L:

The energy provided by the cell divided by its total volume

Enables applications where volume is a consideration (Cars, Personal devices, medical, etc)

Max Discharge Rate:

The highest allowable current, expressed as a multiple of the battery’s rated capacity (C-rate), that can be applied during discharge without exceeding the manufacturer’s specified voltage, temperature, or safety limits.

Enables applications where power is needed quickly (Battery Backup Units, Missiles, Race Cars etc)

Max Discharge Pulse Rate:

The highest short-duration discharging current (C-rate) that a battery can safely accept for a limited time without exceeding its voltage, temperature, or safety limits.

Enables applications with broad power fluctuations (Grid, CNI, Aerospace, EV, etc)

Max Charge Rate:

The highest allowable current, expressed as a multiple of the battery’s rated capacity (C-rate), that can be applied during charge without exceeding the manufacturer’s specified voltage, temperature, or safety limits.

Enables applications where reduced downtime is important to the consumer (EV’s, EVTOL)

Max Charge Pulse Rate:

The highest short-duration charging current (C-rate) that a battery can safely accept for a limited time without exceeding its voltage, temperature, or safety limits.

Enables applications with high sudden current spikes (Grid, CNI, EV)

Cycle Life (80% BOL):

The number of complete charge–discharge cycles a battery can undergo before its capacity falls below a specified percentage of its original capacity (usually 80%).

Enables applications where cost of ownership, total throughput, and reliability are important (Grid, EV, Aerospace)

Calendar Life:

The total elapsed time (usually in years) that a battery can remain usable while in service, regardless of the number of cycles, before its capacity or performance falls below a specified threshold (often 80% of original capacity)

Enables applications where minimized cost of ownership, guaranteed lifespan, and long mission profiles are important (Aerospace, EV, Grid)

Shelf Life:

The period a battery can be stored (typically at room temperature) without significant loss of performance or safety.

Enables applications where the battery may not be used right away (DOD, CNI)

Operating Temperature Window:

The range at which a battery can operate without any damage to internal components

Enables applications where adverse conditions are common (DOD, Grid, Anything with hot/cold climates)

Source: Battery Report 2023 and 2024, Battery Talk: Battery Application Break Down 12/31/2025 (Version 3.0)

Extracted from the PDF; charts and images may read imperfectly.