There’s a Hybrid Concept that Mazda Enthusiasts Wish Will Materialize

Did you know that Mazda has been giving us a lot of information about a possible future hybrid sports car? According to documents filed with the United States Patent Office, at least one electrified roadster is very likely brewing at the automaker. And a recent patent granted to the Japanese company is particularly amazing. It details a hybrid drive system for a rotary-powered “one-row seat vehicle,” with a bank of swappable batteries located behind the driver. It’s a very interesting system that Mazda claims could boost range and keep the car lightweight. The document itself goes back to June 2021, when it was first filed. Published a few days ago as a granted patent, it’s absolutely related to at least one previous doc that describes a similar system. This time, much more detail is provided.

I’m excited to share with you some details about the foundation of the system – a hybrid drivetrain with a rotary engine and three electric motors. You may have read about this before in Mazda patent posts. The main permanent magnet motor, which is mounted to the back of the engine, provides 25 kW (34 horsepower). Additionally, there are two 17 kW (28 hp) induction motors, one for each front wheel, which are driven by a bank of four battery modules, all under 60 volts. It was not mentioned in the old patent why the voltage was relatively low for an automotive traction application, but it seems that it was designed for the safety of workers in the factory, as well as the end user. Rest assured that this system is designed with safety in mind!

According to Mazda’s documentation, they claim that their “workers” will be responsible for replacing the battery. However, their system is designed to make battery replacement a simple process, which can help address any concerns about cruising distance. It’s hard to imagine a Mazda employee riding shotgun in your car after it’s been sold, so it’s unclear who would be responsible for this task in the future. Regardless, it’s important to ensure that this issue doesn’t spoil the fun of driving your new car.

I recommend wiring these modules in a 2P 2S configuration, meaning two modules should be connected in parallel and then connected in series. The parallel/series connections can be completed with MOSFETs, which are high-power switches that are electronically controlled. It’s worth noting that the nominal voltage can vary, and the patent states that anything from 48V to 96V could be provided.

It’s interesting to note that even though the voltage provided by the modules can vary, it’s still relatively low for a hybrid car. However, according to the document, the inverter or other related power electronics can boost this voltage in at least three stages, which allows for higher motor speeds despite the battery’s size. This is a technique that Toyota has been using for years in their hybrid systems, and it can even be done on small projects like a homebrew go-kart. The reason for the low module voltage is likely due to their size and the fact that they need to be handled regularly. Mazda plans to keep two of these modules in the car at all times, while the other two can be removed and replaced. So, unfortunately, you won’t be able to turn it into a pure internal combustion roadster just by taking out all the batteries.

It’s interesting to think about the battery capacity and weight of Mazda’s hybrid car. According to a previous document, the battery capacity was reported to be 3.7 kilowatt-hours, which is a reasonable 925 watt-hours per module. The weight of the modules depends on the type of cells used and the internal cooling present in the casing. Based on a 2-kWh 48V module used in a go-kart, the weight could be around 15 lbs per module, resulting in a total pack weight of approximately 60 lbs. However, this is just speculation. What’s really exciting about this system is that it’s the first of its kind in terms of user-swappable batteries. Although Mazda’s approach to hybrid cars may seem unconventional, it truly makes sense from a driving enjoyment perspective.

It’s fascinating to consider the possibilities of Mazda’s innovative approach to hybrid cars. By utilizing two different electric motors that deliver power in unique ways, Mazda is pushing the boundaries of what we thought was possible in terms of power delivery. The result could be a driving experience unlike any other hybrid vehicle on the market. It’s exciting to think about the potential of this technology and how it could change the way we think about hybrid cars.

Photo Source: Mazda USA