Inspect a swappable main battery, a fixed reserve and equal-energy alternatives. Compare the same requested route and payload; retain independent battery states and explicit service events.
Open the interactive system comparison ยท Open the same scenario in Design
Problem โ solution โ effect โ trade-off
Problem: an operational return reserve leaves energy in a pack that is about to be swapped.
Solution: provide a separately available reserve and lower the main-pack return threshold.
Effect to test: additional main-pack energy used before service, completed duty and minimum reserve margin.
Trade-off: more hardware, mass and maintenance; the reserve may be unavailable when cold, depleted or power-limited.
Problem: a fixed reserve is not refreshed by swapping the main pack.
Solution: track its own state, temperature and recharge opportunity across trips.
Effect to test: repeat-trip completion and replenishment time, including finite site power and ready-pack inventory.
Trade-off: an initial-trip advantage may disappear if reserve recovery cannot keep up with the duty.
Problem: usable kWh does not guarantee enough traction power on a grade.
Solution: separate charge and discharge limits, cold derating and source supervision.
Effect to test: requested versus delivered power, unmet energy and pack temperature.
Trade-off: higher-power or cold-capable variants require characterized cells, cooling and control. The variants here are declared assumptions.
Compare the single-main baseline with a policy-only change to isolate the effect of the return threshold. Compare the dual system with an equal-energy fixed pack to distinguish architecture from added capacity. Retain the same requested route, payload, ambient condition and service requirements. Report incomplete duty alongside energy use: a system that travels less must not look more efficient merely because it delivered less work.
As nominal capacity arithmetic, 95% of 432 kWh is 410.4 kWh and 70% is 302.4 kWh: a difference of 108 kWh, or about 35.7% relative to the latter. The operating-window difference is 25 percentage points. This illustration assumes a 100% starting SOC; it is not an exact terminal-energy result. The default study instead starts at 95% SOC and uses a 5% dual-system return threshold, a 90% charge-SOC window. Modeled terminal energy also depends on voltage, the selected state window, power and temperature limits, and losses. Neither calculation establishes a measured range increase or higher cell energy density. Reserve energy is accounted separately and is not counted again after it has served the load.
A 3C charging rating does not establish reserve discharge power or full charge time. Source handover must also be checked against bus voltage, current limits, protection, contactor or converter behavior and an explicit transient time scale. This route study does not verify the announced millisecond switching claim.
Software verification of declared reduced models. Pack advancement uses the shared native Design solver; route, service-event and comparison orchestration use shared Design JavaScript. Generic parameter assumptions are not measured validation of the announced truck, reserve, switching hardware, ageing or station network. Fleet cost calculation is deferred.
Fleet cost calculation is the next stage. Download operational data from the full study to feed a later cost model.