A month ago General Motors announced plans to wind down production of several under-performers. At the forefront of news coverage on this are the consequences facing factories making those cars, and the people who work there. The human factor associated with the closing of these plants is real. But there is also another milestone marked by the cancellation of the Volt. Here at Hackaday, we choose to memorialize the soon-to-be-departed Chevrolet Volt. An obituary buried in corporate euphemisms is a whimper of an end for what was once their technological flagship car of the future.
[Andrew Rossignol] has a slightly unusual plug-in hybrid vehicle, a Cadillac ELR, and his latest project for the car sees him building a battery-powered portable mains charging pack for it in an attempt to increase its range. If this seems to be a rather cumbersome exercise, his write-up details the work he put in trying to hook up directly to the car’s internal battery, and how a 4 kW mains inverter and an off-the-shelf mains charging station were the most practical alternative.
His first impulse was to hook a second supply to the car’s high voltage bus from a supplementary battery pack and inverter, but in this aim he was thwarted by a protection diode and his not wanting to modify the car to bypass it. So the unlikely solution was to take his battery pack from a second-hand Toyota Prius upgrade kit and build it into a frame along with the inverter and charger. The result is something akin to a portable generator without the small gasoline engine, and while it is hardly the most efficient way to transfer energy from a wall socket into a car it does offer the ELR a significant range upgrade.
The cost involved has probably kept away many readers who would like to hack their hybrid cars, so we’ve seen surprisingly few. This home made Geo Metro supplements its forklift motor with a small gasoline generator. Meanwhile [Andrew] is no stranger to these pages, among the several times his work has appeared here are his rundown on OBD sniffing the ELR, and from a while back, displaying graphics on an oscilloscope including a Wrencher.
[Dean Kamen]’s company, the people behind the Segway, have created a hybrid car that uses a Stirling engine instead of a standard internal combustion engine. Stirling engines are closed cycle, meaning heat is applied to the outside of the cylinder walls. They are generally more efficient than standard car engines, but haven’t been used much outside of industrial applications. We suspect that the drivetrain arrangement is similar to the Chevy Volt where the engine is used to charge batteries which are in turn driving an electric motor. This is different from modern hybrids that can have either electric motor or gas engine driving the wheels. The article is unfortunately full of classic [Kamen] hyperbole and minimal detail. He calls the Stirling engine “an insurance policy” for the electric car since it can recharge the battery. That’s right, folks. If you run out of juice, you can put gas in the car. I doubt many Prius owners will fall out of their chair over that. Being a Stirling engine, we’d be more impressed if you could charge the thing by rubbing warm toast on it.