Comments on: The Vauxhall Ampera — Experienced By A Doubter

By: Zachary Shahan

Zachary Shahan — Fri, 29 Jun 2012 00:38:00 +0000

Yeah, much prefer the look of the Ampera.

By: Bob_Wallace

Bob_Wallace — Tue, 26 Jun 2012 15:04:00 +0000

“The Volt’s 149-horse electric motor spins the sun gear. When starting off, the ring is locked to the case and power flows to the wheels through the planet carrier, providing more mechanical advantage than the Prius’ 80-horse electric motor gets driving the wheels directly. At about 70 mph, the Chevy’s motor is starting to spin too fast to be efficient, so the ring gear unlocks from the case and locks to the smaller motor/generator. Now both e-motors spin, propelling the Volt to 101 mph turning at reasonable rpm in electric mode. The Prius’ gas engine must start turning when vehicle speed exceeds 62 mph.
Once the Volt’s battery is depleted, the engine fires up and clutches to the generator to produce the power required to drive the car. Above 70 mph, when the generator couples to the ring gear, the engine gets a more efficient direct mechanical connection to the wheels. In defense of Chevy’s earlier stance, the only way this gas engine (or the Prius’) could ever drive the wheels without lots of help from the battery is if you somehow MacGyvered up a way to jam the sun gear to a stop.”
Read more: http://www.motortrend.com/features/editorial/1010_unbolting_the_chevy_volt_to_see_how_it_ticks/#ixzz1yubDwUen

By: Gaz

Gaz — Tue, 26 Jun 2012 14:34:00 +0000

Why would you want to charge the batteries from the ICE

By: Neil Blanchard

Neil Blanchard — Tue, 26 Jun 2012 12:54:00 +0000

Hi Bob,

The ideal serial (aka series) hybrid has several advantages that I think make them much more efficient than a multi-mode hybrid; or even a pure parallel hybrid:

The engine required is much smaller because it only needs to charge the battery a little faster than the average consumption rate. (Any engine that has to be able to drive the entire vehicle all by itself must meet the peak rate.) So the serial hybrid engine weighs a lot less, it has no multi-gear transmission, and has correspondingly smaller and lighter fuel and cooling systems, too.

The serial hybrid’s engine only runs part of the time, so no fuel wasted for idling, and the cooling system can be closed up when it is not needed, which greatly improves the aerodynamics of the vehicle. By using the battery as a buffer, the engine can be run as little as 1 hour out of 3.

The smaller engine warms up quickly, and most importantly — it can be fully optimized to run at a fixed RPM because it can drive a fixed load; the generator. This eliminates the need for variable valves and the intake and exhaust systems can be finely tuned to always be running at the peak efficiency.

So, a serial hybrid has a much smaller displacement engine (500cc-1L) that is purpose made for a fixed RPM at it’s peak efficiency. This is ideal conditions for any ICE. It weighs much less, and it can run in electric mode much of the time, so the aero drag can be optimized as well.

A pure parallel hybrid also has some of these advantages, but the engine must be bigger than a serial hybrid because it has to move the vehicle in less than ideal conditions (say up hills) and over a range of speeds, so the RPM must vary and it may require a couple of gears. Also, it cannot charge the battery, so you would often be left without a charge for the end of a long trip, and would have to limp along on the undersized engine at low speeds.

A multi-mode hybrid has more complexity than any other drivetrain — read: has much more weight, and none of the modes are fully optimized. More often than not, both the electric and the ICE have to be used together, hence the uber-complex CVT transmissions in both the Volt/Ampera and the Prius.

Neil

By: Stan Stein

Stan Stein — Tue, 26 Jun 2012 12:26:00 +0000

You guys…..geez….read it again……the 1.4 engine doesn’t runs the wheels…….it’s a generator. It says the electric motors ALWAYS drive the car…(“so at all times, the motors power the wheels”)….so, you have the regen brakes always active when the batteries aren’t fullly charged…..they top the battery off continuously, and the same for the 1.4….it’s function is to keep the battery charged.
I’m a scientist in the renewable energy sector, so I am qualified to say, that all these electric cars are designed backwards….,just like most all renewable energy devices…….my company is just now patenting 4 new technologies, which are a giant step forward in renewable power generation……look for us….Advanced Consulting & Scientific

By: Ross

Ross — Tue, 26 Jun 2012 06:02:00 +0000

Assuming that in extended range mode the petrol/gas engine is driving all the cars electrics it would be unnecessary for it to do an inefficient recharging of the battery.

Presumably regenerative braking does still work and charge the battery.

By: Bob_Wallace

Bob_Wallace — Mon, 25 Jun 2012 22:48:00 +0000

There would be a power loss from driving a generator -> charging batteries -> powering the electric motor.

Possibly less loss to go directly to the power train from the ICE.

By: Neil Blanchard

Neil Blanchard — Mon, 25 Jun 2012 21:57:00 +0000

I don’t think the Volt/Ampera actually charges the battery with the ICE — they supply electricity to the electric motor and/or power the wheels directly with the ICE; but they do not charge the battery.

Which is a poor design decision, in my opinion.

Neil

By: Nicolas Zart

Nicolas Zart — Mon, 25 Jun 2012 18:37:00 +0000

Great job! However, unless the Ampera is different from the Chevrolet Volt, which I don’t believe it is, the gas engine also powers the wheels when needed making the whole Extended Range Electric Vehicle bit far fetched. It’s a great plug-in hybrid.

By: Ross

Ross — Mon, 25 Jun 2012 17:16:00 +0000

Vauxhaul/Opel Ampera has nicer styling than the Chevy Volt which is the same car.

Is it possible to fully recharge the battery using the built in petrol engine if there isn’t a charging point nearby? I know that’s mad from a cost perspective. Is it really any old 240volt outlet, do the local power distribution utility not want to certify it because of the load?