Previously I had heard that the volt was getting a 3 cyl 1.0L engine for "recharging the battery". GM announced today that they are building a new engine plant that will be building a 4cyl 1.4L engine for the Volt and that said engine would run a generator for directly powering the vehicle. Only a small amount of engine power would be utilized for recharging the battery.

Sounds more and more like that Volt is going to be just another normal PHEV (if there is such a thing as "normal" yet). Although, it does make a lot more sense than previous descriptions. The idea of a tiny engine trying to recharge a depleted battery pack while the car was being driven sounded potentially troublesome in some driving scenarios.

One of many links to this story here

 

I read it would not charge the battery at all. Only plug in and regen braking would do it.
Still sounds like a step forward in my opinion. Link

 

I think essentially what this means is once the battery pack is depleted to a certain point (after your 40 miles of electric driving), the car will use the battery the same way a conventional hybrid does... maintaining a reasonable charge "above" the minimum thru regen braking AND engine to ensure the vehicle has at least a few minutes of full performance (max engine + battery) available (hill climbing, passing, etc). People would be PO'd if they found the car's performance to drop significantly after 40 miles.

What it won't do is run the engine at 3000 rpm at the red light desperately trying to bring the battery back up to full charge (something that the original 3cyl 1L engine was supposed to do). Doing that nullifies the value of the whole plug in concept by using a lot of costly gasoline to provide full charge back to the battery. The full recharge will wait until you get back to your garage and plug back in...

 

"Edmunds Inside Line stirred up kind of a hornets nest yesterday when they made the claim the Chevy Volt won't use the engine to recharge the battery. Turns out they weren't exactly right. GM's VP for Global Program Management, John Lauckner, rebuffed Edmunds' claims and stated, in no uncertain terms, that the engine can recharge the battery, but recharging the battery is not its objective. Engines are most efficient when operated at a steady state — tons of tricks can be implemented to optimize performance at a constant RPM, and that's the plan for the Volt.

As with any steady-state output, sometimes there will be surpluses. Those surpluses of electricity not used by the electric motor, as might occur during light loads, will be dumped into the battery so that energy isn't wasted. But recharging the battery is not the objective of running the engine. In addition to extra electricity from the engine/generator, energy reclaimed from regenerative braking will also be stored in the battery. Over an extended period of these surpluses being added to the battery, it's possible for the engine to switch off and the car to return to all-EV mode for an unspecified distance." [EdmundsInsideLine]

 

That does make sense that the ICE would primarily propel the vehicle and only trickle-charge the battery pack. I wonder if the Volt will still have a conventional 12 volt backup battery for starting the ICE if the main battery pack ever gets fully depleted.

 

I have read this a few days ago. Hope I could find a video of this one.

 

The volt runs on an EREV (extended range electric vehicle). When you start out after a full charge, you are driving on pure electric power. Once the batteries get depleted, the small ICE kicks in to recharge the batteries. The ICE NEVER propels the car. It's 100% electric drive. This is a better system than the PHEV, because with the PHEV you still have to use a bit of gas, even for short trips.

In my opinion, the reason for them giving the Volt a larger ICE is to bring costs down. It can now share an ICE with other GM vehicles.

 

Is there any manual control as to when the ICE will come on and start to charge the battery? If the range of the battery is 40 miles and I have a 35 mile drive until charge, I would not want the ICE to come on since I know I can make it home without the ICE charging the battery.

Can the charge provided by the ICE keep up with the discharge of the battery to propel the car? For example, if you are driving on a 60 degree day at a steady 65mph down a flat highway with no wind, will the energy provided by the battery to keep the car moving under these conditions be greater or less than the charge input into the battery from the ICE? This could be another condition where one would want manual control of the ICE charging the battery. If I am about to start out on a long trip under the conditions mentioned above and the ICE cannot keep up with the energy demands, I would want the ICE to start charging the battery right away. This would provide the maximum range for the vehicle. As I start out on a trip, the ICE would not know if I am just going to go 35 miles or if I am going to try and go 500 miles. You can see where manual control of the ICE would help.

 

GM hasn't announced exactly how the car works. However, I'd imagine that there is no way to control the ICE.

The ICE's charge will NEED to keep up with the rate of battery discharge otherwise the batteries will run low.

I'm pretty sure it will always start out in EV mode, then after about 40 miles, it the ICE will kick in and charge the batteries. It shouldn't matter too much. The car's total range is only around 300mi, but I don't think having the ICE going for the first 40 miles will do anything. If your battery is already charged, there will be nothing for it to do. If the battery isn't charged, it will kick in to offset what you are depleting.

 

Forgive me but the underlined part is not exactly correct.

The ICE most certainly will propel the car when the batts have discharged. What makes the Volt interesting is that the ICE lacks a mechanical drive line to the wheels (which is what I assume you were trying to say). There is going to be a mechanical pathway the from the ICE to the generator and then an electric path from the generator to the electric "traction" motor.

The pure electric part of the pathway is fairly efficient, perhaps over 90% when going: ICE-generator-motor.

The reason the ICE's primary job is NOT going to be to charge batteries is because charging batteries with the ICE is very inefficient perhaps down below 30% when going: ICE-generator-batts-motor.

Near as I can tell the Volt has always been designed this way, nothing has changed as far as the ICE-generator-motor pathway is concerned.

If you check out the design of hydraulic hybrids you will find no mechanical connection between the engine and the wheels. The engine powers a hydraulic pump and hydraulic motors push the vehicle. In spite of the missing mechanical drive line the engine still provides all the motive force to move the vehicle.