Secondary electrical source???

[osmigo]

Will the main drive battery serve as the power source for other electrical items on the car, such as stereos, headlights, other lights, blower fans, wipers, electric windows, instrumentation, etc.?

On a normal car, they're powered from the car's 12V battery, which is kept charged via the alternator. On a Volt, if they're powered from the main battery, it seems like these would all draw down from that 40 miles capacity.

If they're powered from a secondary battery, there's no engine running to keep that battery charged, and several of these items operating at once can drain a standard top-line battery in a matter of minutes.

I couldn't find anything about this elsewhere on the website.

[cburk]

I would think that all systems on the car would be operated from the main battery pack. If you read the documentation you'll see that the battery back is never depleted further than 30% and never charged higher than 80% of capacity. Supposedly this is to improve the life of the battery. The 40 miles per charge is what the volt is supposed to get at the end of the 10 year battery life. I'm sure they have come up with the 40 mpc number factoring in all of the other electrical needs of the car such as AC, heat, fans, blinkers, radio, etc, etc.

What this tells me is that when the car is brand new you may likely get a lot more than 40 mpc especially if you don't need to use the heater, AC, etc, etc.

[darthvader420]

I would think that all systems on the car would be operated from the main battery pack. If you read the documentation you'll see that the battery back is never depleted further than 30% and never charged higher than 80% of capacity. Supposedly this is to improve the life of the battery. The 40 miles per charge is what the volt is supposed to get at the end of the 10 year battery life. I'm sure they have come up with the 40 mpc number factoring in all of the other electrical needs of the car such as AC, heat, fans, blinkers, radio, etc, etc.

What this tells me is that when the car is brand new you may likely get a lot more than 40 mpc especially if you don't need to use the heater, AC, etc, etc.

As far as I know, the 40 mile claim is for a brand new battery and for city driving only.

[b_schmatt]

I too am wondering about normal 12VDC systems. Will they have some type of converter and regulator off of the main LI-Ion battery pack to run 12VDC systems. Which reminds me - did anyone see any 12VDC accessory / cig lighter ports anywhere in the interior photos? Or are there another USB power port besides the USB media port?

[OPEC SUCKS]

So what did the EPA test use ?? The one that supposedly achieved 100 mpg. Aren't the new, post 2007 mileage estimates based upon an AC being on, among other more "realistic" driving conditions ??

[swimdad623]

Will the main drive battery serve as the power source for other electrical items on the car, such as stereos, headlights, other lights, blower fans, wipers, electric windows, instrumentation, etc.?

On a normal car, they're powered from the car's 12V battery, which is kept charged via the alternator. On a Volt, if they're powered from the main battery, it seems like these would all draw down from that 40 miles capacity.

If they're powered from a secondary battery, there's no engine running to keep that battery charged, and several of these items operating at once can drain a standard top-line battery in a matter of minutes.

I couldn't find anything about this elsewhere on the website.

In a prior post a few months ago, one of the Volt designers said that the first Volt generation would still have a 12V battery under the hood. The reason for this was that so many of the accessories (lights, radio, power windows, even onboard electronics) are designed for 12V operation, and it would have been expensive to redesign them for another voltage.

They could have eliminated the battery with a voltage converter that ran off the main battery. However, it's likely that the cost of such a converter would have been more than the cost of a battery and a simple trickle charger.

Now, it's possible that the battery might be smaller - like a motorcycle battery. After all, the Volt battery most likely doesn't have to start the gasoline engine, as in a normal car. However, to support all of the 12V electronics in a normal car, it apparently still needs a battery.

[WopOnTour]

Much like the current 2-Mode GM hybrid, the Volt will likely have a 12V battery to support various 12V accessories and systems, but it wont need to be a large one. The 12V battery is really only there to provide a charging load that looks to stabilize the 12V side of the house and to provide a short term 12V source during certain KOEO periods. Since MG1 provides the starting duties for the V8 engine, the 12V battery isnt really part of the cranking system.

In the current 2-mode it's charge is maintained by an electrical converter built into the hybrid control electronics that steps down the HV (300VDC in the 2-mode) to various setpoints that range from 13.0 to 15.5 Volts which keeps the battery charged and all the 12V components and control modules within their operating range.

There is no alternator required since a significant amount of energy is always being recovered through regenerative braking and of course during regular charging from MG1 which is coupled through a gearset to the ICE.

WopOnTour