Published on February 14, 2026 by Electric Le Mans Initiative

Battery + Charging: The 45-Minute Stint and the 2 MW Pit Stop

One-sentence promise: Our concept depends on two linked targets: a ~45-minute stint and charging fast enough to keep total race math competitive.

Concept-Stage Targets

Current working targets:

• stint length: about 45 minutes
• stint distance: about 13 to 14 laps
• pack size: about 150 to 200 kWh
• SOC window: about 10% to 80%
• charging target: about 2 MW
• stop target: 2 to 3 minutes

These are hypotheses, not validated data.

Part 1: Energy Per Lap and Pack Sizing

A rough anchor can be formed from published high-performance EV references, but direct transfer to Le Mans is risky. Le Mans has long high-speed sections where drag dominates and regen opportunities differ from tighter circuits.

If stint energy demand exceeds expected usable window, only a few levers exist:

• improve energy efficiency at target pace
• shorten full-pace stint length
• change SOC operating window
• increase pack size
• leverage neutralization windows strategically

The immediate requirement is a physics-based internal energy model, not optimism.

Part 2: Charging Time Math

Use:

E_add = P * t

For a 200 kWh pack charging 10% -> 80%:

• E_add = 0.70 * 200 = 140 kWh
• At P = 2000 kW, ideal t = 140 / 2000 h = 0.07 h = 4.2 min

That is ideal only. Real pit execution also includes:

• plug/unplug operations
• safety checks and interlocks
• ramp-up/ramp-down behavior
• thermal limitations of pack, cable, and connector

So a consistent 2 to 3 minute stop is aggressive unless one of these becomes true:

1. Effective charging power is materially above 2 MW
2. Energy per stop is reduced (smaller SOC swing)
3. Neutralization timing absorbs part of charging penalty

Part 3: The Real Engineering Problem

Peak power on a spec sheet is not enough. Endurance viability depends on repeatable execution when hardware is hot and timing pressure is high.

Critical constraints include:

• connector and cable handling
• connector/cable cooling
• HV safety interlocks and isolation checks
• pack thermal condition at arrival
• repeatability over many stops

Open Questions (TBD)

• What is our modeled kWh/lap at target pace with aero and mass assumptions?
• What charging curve should we assume across SOC and temperature?
• For a 2 to 3 minute stop target, what must change first: SOC delta, pack size, or charging power?

Written by Electric Le Mans Initiative