Why Tesla’s Metal Air Range Extender Patent Seems Pointless to Us
Awhile back, Tesla Motors filed a patent for a range-extending metal air battery (link to patent filing here).
Though Tesla filed the patent, we don’t see why the automaker would consider pursuing such a device for use in its vehicles.
Here’s the patent abstract:
Abstract: A power source comprised of a first battery pack (e.g., a non-metal-air battery pack) and a second battery pack (e.g., a metal-air battery pack) is provided, wherein the second battery pack is only used as required by the state-of-charge (SOC) of the first battery pack or as a result of the user selecting an extended range mode of operation. Minimizing use of the second battery pack prevents it from undergoing unnecessary, and potentially lifetime limiting, charge cycles. The second battery pack may be used to charge the first battery pack or used in combination with the first battery pack to supply operational power to the electric vehicle.
The problem is that metal air batteries basically self destruct over time. Repeated use renders them absolutely useless.
It’s believed that metal air battery technology is at a stage where only approximately 100 charge cycles can be endured before the battery itself is useless.
So, why would Tesla fit an expensive second battery pack to one of its vehicles to increase range? The answer, at least to us, is that Tesla won’t do this.
The Model S already has more range than anyone could ever desire and we believe that few, if any, buyers would opt for say a $10,000 range extender with an extremely limited lifespan. And, once depleted, how many Model S owners do you think would whip out another $10,000 for a replacement range extender when they realize they seldom used the original one?
The Model S needs no range extender. Perhaps other electric vehicles out there with only 80 or so miles of range could use some sort of range-boosting device, but not the Model S with its up to 265 miles of EPA-rated range.
There’s other arguments that could be made against this use of metal air, including that the vehicle’s primary battery pack would have to be made smaller (hence reduced range prior to the kick in of the range-extending battery) to allow room for the metal air.
Upon seeing this patent filing, we thought it immediately absurd. We know that Tesla will never drop an ICE range extender in one of its vehicles, so the use of a second battery to extend the range would be fitting of Tesla’s promise to remain completely electric, but this metal air tech just ain’t the way to go.