Bidirectional charging — letting an EV send power back to a home or grid — sounds like it should require a whole second set of hardware: a charger that works in reverse, more power electronics, more weight, more cost. A 2024 Cummins grant takes the integration path instead, and it is the more elegant one: use the motor that is already in the car as part of the charging circuit, in both directions.
The record: on September 3, 2024, Cummins Inc. was granted US12077056B2, “Bidirectional electric vehicle charging with multi-phase machines.” The CPC classes are charging and conversion classes — B60L 53/24 (charging using the propulsion system), B60L 55/00 (vehicle-to-grid), H02M 7/537 (DC-AC conversion), plus B60L 2220/54 and 2220/58 (multi-phase machine classes). The “multi-phase machine” is the motor; the patent makes it pull double duty.
Here is the mechanism. An EV motor is a multi-phase machine — its windings and the inverter that drives them form a sophisticated power-electronics system. That same system can, with appropriate control, be reconfigured to act as a charger: the windings serve as inductors and the inverter as a converter, moving power from the grid into the battery, or from the battery back out. The motor is not spinning during this — its electrical components are being borrowed for conversion.
Why is this the clever approach? Because it deletes hardware. A dedicated bidirectional charger of meaningful power is heavy and expensive. If the motor and inverter — already present, already rated for high power — can do the job, you avoid duplicating that capability. It is the same integration logic that lets a powertrain serve multiple functions: stop adding boxes, reuse the capable hardware you have.
Trace it to the product and the significance is making bidirectional charging cheap enough to be standard. If vehicle-to-grid requires an expensive add-on, it stays a premium feature. If it falls out of repurposing the motor, it can become a default capability — which is what would make EVs broadly useful as distributed grid storage. The integration is what scales the feature from niche to normal.
The caveat: a granted method for motor-based bidirectional charging is a technique with real constraints — using the motor windings for charging imposes design trade-offs, and the achievable power and efficiency depend on the specifics. But the principle is sound and consequential. The car is ready to be a two-way energy device; the question is the cost of the wire and the converter. A 2024 Cummins grant answers it by using the motor the car already carries.