VIDEO REVIEW: Electric intro

By: Steve Skinner, Video by: Andrew Britten


Fully electric buses seem to be gaining traction around the world

 

Electric automotive technology is making headlines, led by the Tesla battery-powered car which seems to be accelerating rapidly off the mark.

Less well-known but no less significant is electric bus manufacturer BYD, which boasts legendary investor Warren Buffett as a shareholder and says it has sold more than 5,000 units globally.

This month we test drive a fully electric bus for the first time, in the form of a Chinese-built integral coach. It’s housed at the factory being set up by start-up electric vehicle manufacturing brand Ava.

Ava is based in a giant hangar of 12,500 square metres leased at Avalon airport near Geelong in Victoria, and its global ambitions extend beyond buses to trucks, cars and motorbikes as well.

Ava’s owner is Allen Saylav, who until recently was chief executive officer of another electric bus start-up, Brighsun New Energy.

Suffice to say that our review bus this issue has a rather complicated pedigree, but something both sides agree on is that its model name is "Avass".

The Avass is an example of what appears to be exciting bus propulsion technology.

QUIET ON THE OUTSIDE

Early in the afternoon of our visit to Avalon, ABC videographer Andrew Britten and I were standing near the parked electric coach chatting with Ava engineering staff.

Next minute I looked around and the coach wasn’t there – someone had moved it towards the exit, in total silence. The only sound I could then hear was the squeal of tyres turning on a smooth concrete floor.

It was an almost bizarre first experience of what looks like a conventional bus on the outside, but with radically different stuff going on up the back and underneath.

And if it’s anything to go by, residents near busy bus stops can look forward to more peace and quiet in the future if electric technology takes off.

Instead of a noisy diesel engine are several sets of battery packs, containing numerous individual lithium-ion batteries joined in pairs.

The packs are placed down low on both sides of the bus – behind the steer axle and on both sides of the rear axle. This leaves a normal-sized luggage bin in the middle.

The battery packs are water-proof to a depth of 30 metres, which is a global standard that hopefully never gets tested in real life. They are connected to an electric motor near the back of the bus which of course drives the rear wheels.

There is a charging point at the rear left of the coach, and if you blink you miss it. Behind a little door is a female charging socket.

Come charging time you connect up the male part, which looks remarkably like a conventional high flow diesel trigger and hose attached to what looks remarkably like a conventional fuel bowser.

Saylav says charging time is the ‘burning question’ that everybody asks, adding that broadly speaking it depends on two factors: the on-board technology and the strength of the grid supply.

According to the specs sheet, the charging duration for this one is four to eight hours, but Saylav assures us that figure will drop dramatically in the next generations.

Meanwhile on the left side of what is normally the engine bay in a conventional bus sits a cooling system for the transmission and power steering, with a standard reservoir bottle.

On the right side is a pair of standard 12 volt batteries for the LED lights and starting the ignition; and the air compressor for the brakes and suspension.

Rather than belts running off a diesel engine there are separate little motors for the auxiliary systems.

But when you close all the lift-up panels and doors, the coach looks just like any other on the road.

NOISY ON THE INSIDE

You can’t tell this is an electric vehicle by looking on the inside either. Its passenger capacity of 49 is comparable with conventional 12.5m coaches.

However it’s obvious this is a prototype electric bus by listening on the inside as it drives along.

When you’re seated towards the back, there is a loud motor/gearbox whine as the bus accelerates.

The noise level drops away while cruising, but then comes back with a vengeance when the driver takes the foot of the throttle.

That’s because the regenerative braking system is kicking in, using energy from the wheels to put some power back into the batteries. Not helping in the noise stakes is that this trial bus has a PVC floor.

Saylav assures ABC that internal noise levels will be significantly lower in ‘Generation II’ coaches when they roll off the production line at Avalon, which he expects to be around July.

Not only will they have timber flooring, but they will be direct drive and have a drivetrain motor which will be smaller and lighter. This one has a special three speed ZF gearbox attached to it.

Apart from the unusual noises, there’s another internal giveaway to the fact this is an electric bus.

It’s the digital display showing what’s happening with the electrics – placed in amongst the traditional speedo, tacho and brake air pressure dials.

There’s a maximum voltage of 580; an amp meter to see how much power you are using, and how much power the regenerative braking system is putting back; and a reading for how much power you have left.

ROCKET OFF THE MARK

Fully electric vehicles are renowned for having high torque at take-off, and this coach is like a young horse which wants to bolt as soon as you give it a nudge.

The acceleration from a standing start is rapid, as good as you will experience with any diesel engine. You only have to gently tap the accelerator pedal and the thing takes off.

In fact the acceleration is so good that for slow manoeuvring in either direction, as soon as you touch throttle you then have to whip your right foot onto the brake pedal to control the excessive speed.

After a bit of driving around a couple of quiet country roads near the airport, we took the coach onto the Melbourne-Geelong freeway ramp, where it performed well and got up to merging speed as well as you need and expect.

Trouble was, it then literally took a couple of kilometres on the flat freeway to get up to 100 kilometres an hour.

This no doubt had something to do with the highway tourer diff ratio, although Saylav assured us that the coach performs well up hills. But it also has to do with the electric drive being more incremental than fossil-fuelled drives.

Saylav also points out that once up to cruising speed, you drive an electric bus a bit differently to a diesel.

Keeping the foot flat to the floor doesn’t actually make the bus go any faster, but unnecessarily uses more electric "fuel". The trick is to feather the accelerator pedal.

"Once we get the inertia up we no longer need to keep our foot on that accelerator pedal," Saylav says. "We can back right off, the inertia will take over, we just need to blip it just to supply enough current to the wheels."

Another deterrent to keeping the foot flat to the floor was some sort of strange vibration noise at top speed.

But when feathering the pedal, cruising at 100 kilometres an hour sounded and felt no different to what you’d experience in a diesel powered coach, which seemed truly amazing.

ORDINARY TRAVELLING

For our purposes in driving an electric bus for the first time, the performance of this particular prototype from a ride and handling point of view doesn’t matter much.

And just as well, because the driving experience was certainly nothing to write home about.

The turning circle was terrible; the steering was way too loose at high-speed and too heavy while manoeuvring; and the air suspension driver’s seat was bottoming out.

But the proprietary passenger seats manufactured in Turkey were firmly comfortable quad-stitched leather. And the brakes worked well, with the regenerative braking acting as a mild retarder.

There was a maddening beeping noise coming from the dash for the duration of our drive, which the Ava technicians couldn’t get rid of in a hurry. Nevertheless the bus hadn’t been driven since January.

It’s a nice feeling of environmental soundness riding around in this bus, which as it says on the sides, has "zero emissions" and "zero pollution".

That was correct for where we were actually driving it, but of course the ultimate power source was presumably a coal-fired power station somewhere in the Latrobe Valley.

Electric buses powered by renewable energy are further off in the future.

 

SPECS

MODEL: Avass electric tourer.

ENGINE: There isn’t one!

TRANSMISSION: Three speed ZF

AXLES AND AIRBAGS: Dongfeng

WHEELS: Alcoa alloy

SEATS: 49

DIMENSIONS: 12.5m long, 3.6m high

WEIGHTS: GVM 20 tonnes; tare 15.5

 

 

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