The connection starts with the fact that there are only five major parts differences between the Voltec Drive unit in the second-gen Volt and the new Malibu Hybrid. Greg Hubbard, GM's chief engineer of global electrification, said that these five items are the engine input damper, one of the stators, two of the rotors, and the fact that the Volt's one-way clutch was removed.
While the drive unit is similar, the battery is where the two models are obviously and dramatically different. The Volt's 18.4-kWh pack is an entirely different beast from the 1.5-kWh pack in the non-plug Malibu. The battery cells, for example, are made by Hitachi in Japan instead of by LG Chem in Holland, Michigan as they are in the Volt (GM's first-gen eAssist hybrids also used Hitachi cells, but the ones in the Malibu Hybrid are 75 percent more power dense). The Malibu's pack is the first power-dense battery that GM engineered in-house, since the Volt battery was designed to be more energy-dense, said Andy Oury, GM's lead engineer for global hybrid battery packs. The focus on power density helps the Malibu Hybrid pack eliminate the need for a 12-volt starter. Using the Hitachi cells shipped from Japan, the Malibu's battery is made at the Brownstown Battery Assembly Plant right alongside the Volt packs.
The Malibu's pack is the first power-dense battery that GM engineered in-house.
Even after the Volt left the engineering department, it influenced the Malibu. Hubbard said that Volt drivers made it abundantly clear to GM that one of the things that they enjoyed the most about their car was the quiet, smooth electric drive. And that's why the Malibu emphasizes that EV aspect as much as it can, despite its smaller battery pack.
Looking forward, Hubbard said that the Voltec powertrain could be expanded and scaled up dramatically to other models and for more mass-market vehicles. Those of us who remember all those hints and rumors about a plug-in CUV from about five years ago wonder if it's about time for GM to finally reveal what it's been working on.
UPDATE: This post has been updated to clarify that the Malibu Hybrid does have a 12V battery, but it does not have a 12V starter. The engine is always started by the HV battery and the motors inside the drive unit.