New Car Focus: BMW i4

By making its latest electric vehicle simpler, Rob Marshall finds that BMW has made the electric car better.

Regardless of whether you are a Bimmer liker, or hater, the company deserves credit for its stance on EVs. Back in 2008, BMW had embarked on ‘Projekt i’, an exercise that involved leasing 500 Battery Electric MINIs to selected North American punters and a further 24 to designated Londoners. This was not environmental greenwash. As BMW saw its moral responsibilities extending beyond the motorcar and into its ‘fuel’, it partnered with Norsk Hydro, the Norwegian hydroelectric firm that generated 28% of Germany’s total electricity supply at the time.

Sure enough, the fruits of the ‘Projekt’ included a continued relationship with hydroelectric power, which BMW now sources more locally and uses it in its factories. This is a crucial point, because EV’s environmental worth is undermined, if produced in a country, where fossil fuels provide most of the electricity, which is the situation in Germany, unlike the UK. ‘Projekt i’ also spawned the intriguing and promisingly different i3 and i8 models. Unfortunately, those high-voltage BMWs were built on expensive bespoke platforms and, despite being interesting and desirable, they are hardly mainstream. The new i4 five-door hatchback, or ‘Gran Coupé’ in BMW marketing parlance, is being launched alongside the iX SUV. Both vehicles are underpinned by the same basic Cluster Architecture (CLAR) BMW’s new i4 Battery Electric Vehicle (BEV) is a Gran Coupé (i.e. a five-door hatchback) with dimensions that are similar to those of a current production 3-series. Pictured is the rear-driven i4 eDrive40 platform that is shared with other petrol/diesel/hybrid BMWs, including the G20 3-series.

The BMW i4 eDrive40 is rear-driven, using a 335bhp (250KW) motor, and possesses a 366 miles range between charges and can dispatch 0-60mph in 5.6s. The i4 M50 has the honour of being the first all-electric BMW M car and is equipped with an additional electric motor on the front axle, giving all-wheel drive capability (albeit still with a rear drive bias) and a combined output of 536bhp (400KW), translating into a 0-60mph acceleration time of 3.9s and a 317 miles stated range.

The fifth generation eDrive drive unit comprises the electric motor, inverter and a single-speed transmission. BMW claims it has a 50% higher energy density than a current i3.

BMW claims that the electric drive motors boast a 93% efficiency rating, which helps to keep down the battery size and weight.

Addressing the critics…

The i4’s handsome but conservative looks hints at technical convention. Indeed, on the surface, there is little to surprise and delight: the battery pack is fixed to the floor pan, while the main motor/transmission/differential is mounted beneath the boot floor. Yet, looking closer reveals clever thinking to address common EV criticisms. While the precise battery cell technology is not revealed, BMW has made the batteries less bulky, championing a cell height of 110mm. It is also another manufacturer that realises how disproportionately heavy battery packs harm handling and efficiency. It has also strived to keep pre-assembly component distances as low as possible. BMW produces its prismatic cell modules in Dingolfing (Germany), the flexible assembly specifications of which vary according to model. The batteries are then transported to Munich. The i4 possesses four modules, containing 72 cells each and three 12-cell modules, giving a gross energy content of 83.9kWh. The battery warranty lasts for just under 100,000 miles, or eight years.

While it cannot do much about the locations in which the precious metals are situated, BMW has taken the human rights problems of cobalt mining into its own hands, by sourcing the rare element from mines in Australia, rather than the Democratic Republic of the Congo. The company has also strived to reduce the cobalt content within the battery packs, although as the ~5% cobalt (traditionally) accounts for ~95% of a traditional high voltage battery’s scrap value (lithium is relatively worthless), this might make it harder to justify recycling from an economics point of view. Even so, BMW claims a 90% recycling rate, compared to the EU legal limit of 50% by weight.

BMW i4 assembly takes place in Munich, on the same production lines as petrol/diesel/hybrid 3-series and M3 models.

The i4’s high-voltage battery pack is fitted to the underside by a fully-automated system.

Perhaps more importantly, BMW utilises electromagnetism to replace permanent magnets within the drive motors, avoiding the need for expensive and rare earth elements to be used in their production. This is a radical departure from convention, by making its EV less dependent on very rare and expensive elements. With the US considering the imposition of tariffs on neodymium magnet imports, BMW’s decision may be crucial to reduce the cost of EV production – although whether these savings will be passed to the customer, or not, is another question altogether.

Under the skin…

The voice-activated HVAC system possesses three zones. The cabin filter uses nano-fleece technology and more conventional activated carbon to enable ultra-fine dust and even certain micro-bacterial particles to be kept out of the cabin. A pre-conditioning function can be activated by the driver via the BMW smartphone app, prior to entering the car.

The basic thermal management (i.e. not just cooling but also heating) for the battery and associated hardware comprises three coolant circuits, interconnected by electric valves, all of which share a common expansion tank. This can, for example, allow heat from the drive motor to warm the battery pack. The new heat pump system uses 75% less energy than the current i3 and consists of a high-voltage refrigerant compressor, a pair of evaporators, a water-cooled condenser, and two 9KW heaters for extremely cold conditions. Surprisingly, the resultant energy savings can increase driving range by up to 30%. While the advantages offered by enhanced battery density, less weight and a more efficient drive unit benefit handling and acceleration, BMW has also considered that EVs tend to have feeble towing capacities. Yet, the i4 can tow up to 1,000 kgs.

Dependent on specification, up to 40 ADAS systems can feature, although they all work using camera, radar and/or ultrasonic sensors. Out of the six categories of automation, defined by the Society of Automotive Engineers, the i4’s systems achieve Level Two (i.e. ‘partial automation’), where both steering and speed are controlled simultaneously. While Distance Cruise Control is hardly novel, the i4’s system can also stop the car at red traffic light signals. While BMW says this feature is unique to the segment, it has not been confirmed if its availability is restricted only to the German market. The Route Monitoring function is another noteworthy feature, because it uses the satellite navigation system to select the appropriate speed for the selected route.

Summary: By normalising its new BEV, BMW has improved the electric vehicle in several important ways, especially by reducing its environmental impact at the manufacturing stage. The i4 will be available in the UK from November. Prices start at £51,905 for the i4 eDrive40 and commence at £63,905 for the i4 M50.

Compared with the i4 eDrive40, the i4 M50’s suspension differs by possessing adaptive M suspension dampers, an additional front strut brace, an increased track width (26mm front, 12mm rear), increased negative camber at the front axle and additional rear axle reinforcement. Both models boast self-levelling rear air springs.

 

Lotus Evija makes its debut in London

The world’s first fully electric British hypercar, the all-new Lotus Evija, has been revealed. With a target power output of 2,000 PS and a price tag of £1.7m.

The Evija is the first Lotus road car to feature a one-piece carbon fibre monocoque chassis.

At the heart of the Evija is an ultra-advanced all-electric powertrain. It has been developed with technical partner Williams Advanced Engineering. The battery pack is mid-mounted immediately behind the two seats and supplies energy directly to four powerful e-motors. With a target weight of just 1,680 kg, it will be the lightest pure electric hypercar ever to go into series production.

The Evija has five driving modes – Range, City, Tour, Sport and Track. It can race from 0-62 mph in under three seconds and accelerate to a top speed of more than 200 mph.

Not only does the Lotus Evija feature the world’s most powerful automotive drivetrain, it also boasts the world’s fastest charging battery. The battery has the ability to accept an 800kW charge. Although charging units capable of delivering this are not yet commercially available, when they are it will be possible to fully replenish the battery in just nine minutes.

Using existing charging technology – such as a 350kW unit, which is currently the most powerful available – the Evija’s charge time will be 12 mins to 80% and 18 mins to 100%. The car’s range is 250 miles (400 km) on the WLTP Combined Cycle, or 270 miles on the NEDC Combined Cycle. Lotus is in discussions with external suppliers on a charging solution for customers.

A £250,000 deposit secures a production slot. Order books are now open through www.lotuscars.com.

Tenneco supplies suspension on Jaguar I-PACE all-electric SUV

Tenneco is supplying suspension components for the new Jaguar I-PACE all-electric luxury crossover SUV. The I-PACE  features Tenneco’s passive front and rear dampers, coil and air spring suspension modules, engineered to improve ride performance and stability.

“These suspension modules incorporate designs and materials that offer important benefits for all-electric vehicles such as light-weighting, underbody space savings and simplified vehicle integration.” said Neville Rudd, Senior Vice President, Tenneco Global Ride Control.

Tenneco’s suspension modules include plastic spring seats, an aluminium top mount and other lightweight components that can help offset the weight of electric motors and batteries, offering improved vehicle performance.

Hyundai Ioniq Electric (AE-EV) (2016-Present)

Introduced in 2016, the Hyundai Ioniq is available in hybrid, plug-in hybrid and all-electric variants. Because the electric version has a much larger battery than its hybrid stablemates, it does away with the usual independent rear suspension in favour of a simpler beam axle. The Ioniq Electric uses a 88kW electric motor and a 28kWh battery. The Ioniq EV’s superb aerodynamics, thermal management and electric drivetrain helped it to become the most energy-efficient car ever tested by the US EPA, with the hybrid and plug-in versions also offering impressive economy figures. This article only covers the electric version which is distinguished by a smooth grey front end.

Battery

The electric version of the Ioniq has a 360V Lithium-Polymer battery pack. The useable battery capacity is 78 Ah/28kWh. There are six 6-cell modules (numbered 1, 2, 3, 10, 11, 12), and six 10-cell modules (numbered 4-9).

Thirteen voltage protection devices (VPD) are located around the battery pack. These are physical switches that are disconnected if a battery module physically expands due to overcharging. In this case, the high voltage system will be switched off and the car undriveable.

The high voltage contactors are located within a Power Relay Assembly- one for the negative and a main and pre-charge relay on the positive side. Pre-charge resistor spec is 40 Ohms. The PRA also contains the two relays for rapid charging (QRA) and for battery heating.

The battery pack is air-cooled. A fan in the offside rear of the vehicle pulls air through the pack from air vents under the rear seats.

The driving power will reduce as the battery state of charge gets low to prevent high current draw at low SOC damaging the battery pack. As with all EV batteries, the full capacity is not used- 28kWh is the useable figure, with the whole capacity being a little larger. Some capacity is also kept back and is used to mask degradation.

Battery charging

The Type 2 CCS charging connector is located on the nearside rear wing. The liquid- cooled OBC (On board charger) is located under the bonnet, sandwiched between the EPCU and the motor.

A Charge Control Module is located under the front passenger seat. It converts the PLC communication from the external charging post into CAN that can be understood by the rest of the car. Charging speed is 6.6kW on AC, and 100kW on DC CCS, although there are not currently many charging stations in the UK that can supply more than 50kW.

Three blue charging indicator lights are fitted on top of the dashboard. The operation of these is similar to that of the Nissan Leaf but not quite the same. During charging, the first light will flash until the battery reaches approximately 1/3 full, at which point the first

light will be on solid and the second light flash, and so on. All three lights on means the car has just finished charging. All three lights flashing means a charging error has occurred. The centre light flashing means a charging timer is set. The end light flashing means the 12v battery is charging, either for a top up, or because remote climate control is on.

The red dashboard warning light indicates charging in progress, and turns green when complete but still plugged in.

Motor

A 88kW permanent magnet three-phase AC electric motor is used, with inverter built into the EPCU. When replacing the motor or EPCU, it is necessary to carry out Initialisation of Automatic Resolver Offset calibration. The cooling system is bled via diagnostic equipment.

Cabin heating and cooling

An electric compressor is used, and a heat pump in addition to a PTC heater. The PTC heater runs from the high voltage system. The PTC heater has a high-voltage interlock circuit which appears to be joined to the HVAC ECU, and then sent over CAN. This would suggest a fault in the HVAC ECU or its network would cause a non-start, although we have not been able to verify this at the time of writing.

The refrigerant circuit is as follows. The system can collect waste heat from the high- voltage cooling system, making it more efficient.

When in cooling mode, the system operates like this. With the various valves in these positions, the system operates the same as any other air-conditioning system. Flaps in the car (not shown) divert the air away from the internal condenser. The internal condenser therefore effectively just acts as part of the pipework. The heat is given up at the front of the car, and passed through an expansion valve to cool the evaporator.

When in heating mode, the valve positions change. The valve shown at the top of the diagram is now closed. There is now a pressure change in the internal condenser, causing the heat to be “dropped” here. The now-cool refrigerant then goes on to collect heat from outside air, and from the heat exchanger (which Hyundai calls the Chiller). The evaporator is now out of the circuit.

For demisting, it is advantageous to operate the heating and air conditioning at the same time. The Ioniq has another trick up its sleeve here. The valves are operated as follows:

This arrangement allows heat to be collected in the car, and dropped in the car. This can demist the vehicle with minimal operation of the PTC heater.

You will notice there is a condenser bypass valve that is in the same position in all the diagrams. This is opened if excess refrigerant is accumulated in the condenser.

Electrical system

A DC-DC converter (known as LDC) is built into the EPCU (inverter). The 12v battery is charged when the vehicle is in ready mode, when charging, and when pre-heating/cooling.

There is an option in the menu for Aux Battery Saver+ (under User Settings > Other features). When enabled, this will automatically charge the 12v from the high voltage battery as required, preventing a flat 12v battery albeit losing a little from the main battery. Aux Battery Saver+ operates for a maximum of 20 minutes at a time, and if the car is unplugged, will check on the battery every 72 hours. If it operates for ten times in a row, the system is disabled as there is either a parasitic drain or the 12v battery is faulty. A dashboard message will tell the driver the battery saver has been used since last parked.

A synthesised noise is created by the car, known as VESS. The Ioniq features various driver assistance systems. These are not covered by this guide or by HEVRA Support at this time.

Braking system

The braking system consists of a Pressure Source Unit (PSU), and a Integrated Brake Actuator Unit (IBAU) on the master cylinder.

The PSU generates and stores hydraulic pressure at approximately 180 bar, and feeds it to the IABU. The IABU can send this to the calipers when regenerative braking cannot provide the necessary brake force. The IABU also handles ABS and ESP functions, emergency backup (hydraulic link to pedal), and simulated pedal feel. A stroke sensor on the pedal measures driver demand- this must be recalibrated whenever it or the IABU is replaced.

If it is necessary to release the pipework between the PSU and IABU, use diagnostic equipment to release the hydraulic pressure. Stroke sensor calibration should be carried out on refitting. In the event of a total failure, a valve within the IABU connects the pedal to the wheels to provide braking on all four wheels with no servo assistance.

Noises from the brake pump when opening the driver’s door, repeatedly pressing the brake pedal, or pressing the pedal particularly hard are all normal. Brake bleeding is quite an involved procedure- see Hyundai factory brake manual.

Further information

Warranty information:

Standard vehicle warranty: 5 years/unlimited miles

EV battery warranty: 8 years/124k miles

Theoretical Layout

Note: Procedures described are for guidance only. Refer to vehicle manufacturer’s technical information for up-to-date procedures. HEVRA cannot take responsibility for injury, malfunction or accident.

 

IMI urges government to invest as much in EV skills as charging infrastructure

Screen Shot 2017-11-19 at 10.09.51The latest data shows that electric and hybrid sales are experiencing record growth while sales of diesels have taken a dive. However, according to the Institute of the Motor Industry (IMI) the EV revolution, and the £51bn contribution it is expected to make to the UK economy, is at risk if the government doesn’t look at the bigger picture.

There is still a serious lack of infrastructure to support these vehicles and the IMI has found the UK has a 13:1 ratio of electric vehicles to charging points. It also found that insurance costs can be 50% higher for electric and hybrid vehicles compared to petrol or diesels; a direct consequence of the fact only 1% of all technicians are currently trained to work safely on the high-voltage technology. The IMI believes the UK will be overtaken by the rest of Europe if the government doesn’t take immediate action.

Steve Nash, Chief Executive at the IMI, says: “With almost all technicians currently trained to work on high-voltage technology working exclusively for manufacturers’ franchised dealers, the UK will struggle to be a leading player in new vehicle technology if government don’t build on the basic foundations such as the infrastructure and skills base to support motorists when they make the switch.

“With a new emissions test being introduced this month, government is clearly taking this matter seriously. A much needed investment in the charging infrastructure would, of course, set the UK apart from competitors across the globe. But it is essential that this financial support is spread further to support the service and repair sector, and in particular the independents, to gain the required knowledge.

“Government is back in office and a new transport committee is in place, so the IMI will continue its campaign for the introduction of a licensing scheme for those working on electric vehicles. We’ve asked the government to contribute £30m to support the uptake of training to facilitate the requirements, and the IMI has a new Electric & Hybrid Vehicle qualification to support this.”