eDrive: How BMW’s plug-in hybrid tech is coming to its entire range of cars

Having arrived a little late to the game of selling electric cars, BMW is now set to become a leader in the field.

By the end of 2014 the company will offer one pure electric car and four different plug-in hybrid models – more electrified vehicles than any other automaker – with plans to expand the range quickly if the need arises.

Sales of plug-in hybrid vehicles now seem likely to increase at faster rate than pure electric vehicles, and the key to offering a wide range of plug-in hybrids is a to have a powertrain that can easily and cost-effectively be installed into different models.

BMW’s powertrain is called ‘eDrive’.

Two different sources of power

Plug-in hybrid eDrive powertrains comprise of a powerful electric motor and a turbocharged gasoline engine. The exact configuration can change – for example the i8 sportscar has a three-cylinder engine while the X5 eDrive SUV has a four cylinder engine – but the basic recipe remains the same.

The size of the battery that supplies the electric motor is also variable, although as space is at a premium in all cars the scope for change is limited. The carbon fiber i8, for example, has an electric range of 22 miles from its 7.2kWh battery pack while the heavier X5 eDrive reportedly needs a 9.0kWh battery pack for a lesser zero emissions range of 18 miles. Top speed in electric mode will be around 75mph for all eDrive models.

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The battery pack at the rear feeds the electric motor that’s integrated with the car’s transmission (highlighted)

The i8’s electric motor is also considerably more powerful than the one in the X5 eDrive, highlighting another area where BMW will be able to differentiate between models and, perhaps in the future, trim levels. Just like we currently pay a premium for the same model with a more powerful engine, buyers will be able to spec the electric motor in their BMW eDrive.

Drivers will refuel an eDrive plug-in hybrid’s gasoline tank like they would any other car, but will also need to plug-in to the grid to replenish the battery to get the most from their vehicles.

Why is plug-in hybrid tech so effective?

The simple answer is because it means the car can behave like a pure electric car or a solely gas-powered car depending on circumstance. With a 22-mile range and charge time of 3.5 hours, when the i8 goes on sale many owners will be able to commute during the week using electricity alone, charging up overnight at home and at work during the day.

The same applies to the X5 eDrive and almost any other hybrid vehicle on the market. Volvo’s V60 PHEV has an electric range of 30 miles, increasing the potential for zero emissions commuting and the Chevrolet Volt’s 38-mile electric range even more so.

bmw-edrive-plug-in-hybri-1

More BMW eDrive owners will plug-in to recharge overnight and at work – if they’re lucky

The flip side is that once the lithium-ion battery is depleted the engine awakens to give owners an overall range comparable to conventional cars – there are no drawbacks when it comes to convenience. BMW’s turbocharged engines are also among the most efficient of any car, so drivers will return decent gas mileage even when the battery is completely out of charge.

eDrive BMWs will also have a performance benefit over standard models, as the electric motor and gasoline engine can combine to deliver maximum power. In the X5 eDrive this means 270hp and razor sharp throttle response thanks to the near-immediate torque from the electric motor.

Which BMW models will get eDrive?

The BMW i8 and i3 Range Extender already use plug-in hybrid technology, although its configured quite differently to meet the differing expectations of owners.

The X5 eDrive SUV is due this year, at least in Europe, and a 3 Series eDrive was recently spotted cold-weather testing, suggesting that it will be the second ‘normal’ BMW eDrive model.

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The X5 eDrive will be the first non-‘i’ electric car from BMW, but will act as a template for the entire range

BMW has recently said that it intends to have a plug-in hybrid in each and every model line, which seems ever more likely given the impressive performance and economy gains on offer and ever-tightening European Union emissions regulations.

While the technology helps larger cars like the X5 become a little more responsive and economical, it’s smaller cars such as the new 2 Series that will really benefit from electrification, with longer zero emissions range and greater performance benefits because of their relative lack of weight.

Posted by Richard Lane

Richard is a London-based automotive journalist specialising in future mobility and sustainable design. Having fallen for cars because of the virtues of a particular German flat-six, it's what we'll all be driving next that now interests Richard most. Dream garage: Alfa Romeo GT 1300 Junior and a Detroit Electric SP:01.

  1. The cutaway views of the X5 edrive show what looks like two lead-acid batteries behind the high voltage battery. Does anyone know what those are used for and why two of them?

    Reply

    1. The system uses lithium-ion for the drive battery, flooded lead-acid for the starter and advanced lead-acid for the hotel loads.

      Reply

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