Drivetrain &
Technology

The Mazda MX-30 is Mazda’s first production battery electric vehicle, but Mazda has a long history of technical innovation when it comes to alternative power sources and battery powered vehicles that includes a host of concept cars and limited production prototypes. This includes the radical 1970 Mazda EX005 bubble car concept, which featured a rotary engine charging electric motors. The 1972 Mazda Chantez EV was another early concept and it was followed by other concepts like the 1991 Bongo EV, the 1997 Demio fuel-cell EV FCEV and the 2013 Mazda2 EV with its rotary range extender. There was even a trio of Mazda MX-5 EV prototypes produced in 1993.

So alongside Mazda’s famous development of hydrogen powered test cars in the 90s and 2000s, electric power has long been in the sights of Mazda’s engineers. Key to Mazda's philosophy is the idea and concept of the right power source in the right place at the right time. The company's 'well-to-wheel' approach to emissions measurement concerns not only the CO2 emitted by cars themselves whilst driving, but also the emissions caused by the extraction and refinery of fuel, or the generation of electricity. Moreover, in the context of EVs and the batteries they use, Mazda considers it important to consider the need to reduce CO2 emissions over their entire life cycle.

Life-Cycle Assessment (LCA) is a technique designed to measure - in addition to well-to-wheel emissions - the total environmental impact of a product over its entire life, from the extraction of the raw materials necessary for production through to end-of-life disposal. Following a study by Mazda and the Kogakuin University, the company's LCA research has shown that, over their entire life cycle, EVs with smaller batteries tend to produce lower CO2 emissions than comparable diesel-engined cars. To that end, Mazda believes that the MX-30's battery capacity of 35.5 kwh provides the optimum balance between a driving range which gives customers peace of mind and CO2 emissions from an LCA perspective. Furthermore, this keeps overall vehicle weight lower for good handling and greater agility, which is currently not the case for many EVs.

Mazda’s e-Skyactiv system's high-voltage components include the motor, battery pack, inverter, and DC-DC converter. The inverter converts direct current from the battery to alternating current to drive the motor, while the DC-DC converter steps down the voltage to supply power to the car’s 12V auxiliary equipment. The motor, inverter, DC-DC converter and junction box are integrated into a single high-voltage unit that is mounted toward the front of the car. The size of the high-voltage battery mounted beneath the floor was carefully chosen to minimise CO2 emissions throughout its life cycle, from resource extraction through to battery disposal. The motor is a water cooled AC synchronous unit with a maximum power output of 105Kw and maximum torque of 265Nm. The prismatic cells of the 355V lithium-ion system battery generate a total electric power output of 35.5kw.

To reduce its height and minimise its intrusion on cabin space,  the battery pack features a high-density battery module, thin busbar wiring to reduce the size of wiring between high-voltage parts, and a thin cooling system.

The battery case is rigidly integrated into the MX-30 bodyshell to enhance overall vehicle stiffness. And both normal and rapid charging ports are packaged together and accessed from the right rear quarter panel in the traditional fuel filler location, with the onboard AC charging cable stowed in the luggage area.

Another feature is the harmonious control between the system and the vehicle that reduces power consumption to maximise the amount of energy that goes directly toward driving. With a maximum system power of 107kw/145 PS and a maximum torque output of 271Nm, the front-wheel drive MX-30 will accelerate from 0-62mph in 9.7seconds and has a governed maximum speed of 87mph. The MX-30's WLTP measured driving range is 124miles+ .

The MX-30 battery pack features a refrigerant cooling system that cools the battery pack when the temperature rises. The compact system adopts thin cooling tubes attached to the bottom plane of the battery module, which make contact with a heat exchanger. A sensor constantly monitors the battery’s temperature and controls the flow of coolant as needed. By maintaining the best possible battery temperature even on hot days, the system helps protect the battery pack from degrading due to heat. Co-operative control between the air-conditioning and battery cooling systems achieves effective cooling performance for both systems.

Safeguarding the high-voltage components, a control system instantly shuts down power flow when it detects any irregularities, and a protective structure protects the battery from external forces in the event of a collision. These measures prevent electric shocks in the event of accidental damage to the high-voltage components.

The e-Skyactiv system can be charged using AC power of up to 6.6kW, or rapid-charged using DC power. The model supports 125 A DC charging with COMBO standard and the battery can charge from 20% to 80% in 3 hours using AC power, or in 36 minutes using DC power ++.

For extra reading on Mazda’s ‘right sized battery’ approach click here: 

https://www.insidemazda.co.uk/2020/06/29/mazda-mx-30-right-sized-battery-strategy/

+ The actual range depends on various factors such as individual driving style, speed, route profile, load, ambient temperature, and the use of components in the car that consume electricity (e.g. air conditioning, heated seats).

++ 36 minutes charging time is based on an ambient temperature of 20°C. The exact charging time depends on various conditions at the time of charging, e.g. the type of charger, battery condition, charging patterns, as well as the battery temperature and ambient temperature. In cold conditions, both battery and ambient temperature will impact the charging time required and, in certain situations, this may lead to a significant increase in the charging time.