Thanks
Andres

I basically agree with Mitch’s statement:
“I think that the Volt will monitor battery temp, if plugged in…”

Apologies if I’m repeating what someone else has said.

If GM allows us to schedule pre-heat/pre-cool of the interior compartment if plugged in, (e.g. Turn-on the air conditioner or heater 5 minutes before we leave), then an option to pre-warm the battery should also be included if the car detects the battery temp is too low. I would also like to inhibit the startup of the genset if only defined performance band of the car is affected and it will not damage electronics or battery. Driving the car will eventually warm the battery from current draw. The goal for this driver is to not use gas. How about a secondary “energy conservation” or “car performance/behavior” menu that allows us to choose how frugal the car should be on energy usage. Give Joe Blow the default menu, but allow the rest of us to buy the shop manual (if required) and fully take advantage of that limited energy contained in the battery. Definitely don’t apply the same thinking, where on my 1988 Toronado where there is no way to bring air in through the dash vents without running the air conditioner. Everyday that the temperature is over 40 some degrees Fand the climate control system is on, it will run the gas consuming air conditioner compressor. Other GM cars had an econo button that would disable the compressor. I’m expecting all sorts of options similar to this to make the car stretch those electric 40 to 50 or 60 miles. Surely GM will offer “presets” of normal, sporty, or econo modes.

Will this make the software too complicated? The car already has to address these issues for basic car operation, so while the control modules are written, behavioral constants can be used to dictate the cars behavior, where those constants can be loaded from default firmware or flash ram holding the owners preferences. I’m NOT asking for a user scripting language to taylor car behavior.

GM knows how to do electric motors, inverter/controllers and even batteries. The real product advantage will be the driving experience and the human to machine interface. Once all of the physical design issues are layed out, software is what will make the Volt a dream or a nightmare to drive. I have confidence that GM can do the software very well if they want to.

Of course GM has thought of this before, just want GM to know that the consumer is also thinking and has similar expectations.

Yes, I’ll raise my hand to be a Beta or even an Alpha tester for the above software features fully well aware there could be some bad experiences. Cars are finally advancing and I will gladly participate!

When I was at a competitor OEM we had a an engine ECU developed with TargetLink while the vehicle controller was both hand-coded C and Embedded Coder auto-generated C. Then you look at supplier developed systems like ABS and transmission controls, they will be a mix depending on what the supplier is comfortable with.

On the Volt there will be code developed by GM, code by the Battery Supplier, code by the Charger supplier, etc.

I generally find references to li-ion technology as used in cell phones and laptops freezing and becoming permanently non-functional at -40. I can’t find a credible source to reference, however, so take it with a grain of salt.

I looked at A123’s specs for their ANR26650 product and it specifies operation range from -30C to +60C.
Maximum storage (non-operational) range -50C to +60C.
http://a123systems.textdriven.com/product/pdf/1/ANR26650M1_Datasheet_AUGUST_2008.pdf

So, indeed, -40F/C is somewhere around the point of permanant battery damage. It’s clearly out of the safe operation range. So, if you’re unfortunate enough to have to go to work when it’s -40C (or, heck, even comparatively balmy -30C (-22F)) out and parked your car outside for 8 hours the batteries (A123’s chemistry, anyway) won’t function. Lutz is presenting a credible scenario even for temeratures quite a bit higher than -40.

Remember that there are many systems in the vehicle being written by various groups so multiple appproaches will be used.”
———————————————————————-

While you sound as if you know what you are talking about… I’m somewhat doubtful.
“Multiple approaches” may be used, but I doubt the programming language will change… ALL of GM uses the same CAD software, I bet all of them also use the same programming language… but I admit I might be wrong.
Undoubtably thoughout one system they all use one language. I can just imagine someone trying to compile a java file with a C++ file with a java compiler and it would have a hissy fit about any pointers! !

It is called the “customer depletion point” because that is the lowest ‘point’ a ‘customer’ can ‘deplete’ the battery. In these sorts of battery major deregation occurs closer to 20% capacity not 30%. My bet is that this zone is what is going to be used for peak power and your additional miles to home.

Note: You do not want to use the ICE to fully charge the battery, no matter how much you think you do. The reasons being: 1. It wastes a lot of energy to charge the batteries.. and then later use that charge to move the vehicle – it makes more sense to just move the vehicle with that energy. (It loses efficiency 2. Shallow charges are bad for battery life. 3. It would take a long time to gain any charge on it.

Once at 20 – 23% my bet is that the battery will completely shutoff and the car runs only on ICE. My thought around this is that if you make many short trips around your home, the battery will not deplete enough to go out of the warranty (ie reduce lifetime). If you drive without gas, my guess is that you won’t get any power from the battery at 15-20% – it’ll be like running on fumes. (It may allow you to drive until 0% but that I’m sure will void warranty)

Those are my thoughts and opinions on that. (Subject to change of course)
~Bob

Remember that there are many systems in the vehicle being written by various groups so multiple appproaches will be used.

And as far as OnStar logging the use and possible abuse of the battery – this is not really necessary. The battery controller will certainly be monitoring the environmental and operational conditions that it sees and this information will be recoverable. Whether this is used to deny warranty claims or not will most likely be a policy decision by GM, not a question of it not being available.

Engine ECUs already capture this kind of information for the ICE.