Very hard to impossible to test a lithium battery for remaining life.. it usually either works or does not, it may be on the last 20% of remaining cycles and you will not know it. Hopefully GM will make the pack tamper proof.

I am sure that a dealer or a repair shop will be more than willing to test your batteries to make sure they are in good shape before you buy, just as they do today for a used car.

“Good article Lyle,

It would be interesting to understand the inner workings of how exactly it gives out the same approximate range from beginning to end. I guess that means it expands pack usage over time, but I wonder if this expansion comes from data on charge cycles, linear usage or real-world practical performance metrics

It would seem they are really trying to optimize the life of this battery, I wonder if that is out of a true desire for efficiency or a serious concern about the viability of the pack over time.

I will also note this statement with a little concern, “So that fact whether its 38.2 miles or 40.2 miles when you’re out of electric range….” is the first time I have ever heard any number but 40 from GM, and we are talking potentially on the very first use.

It sounds like my Volt out of the box might not be getting 40 miles.”

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I agree, another 5 star article from Lyle. He is so good at cutting thru the BS and getting good info straight from the original source.

I’m just guessing (but I’m pretty sure about this guess) that GM will program the Battery Controller so that you always get enough energy required to drive 40 miles *on the EPA prescribed drive cycle* (say 8 kWh, or whatever the exact figure is). The battery could give more than that when new, but not giving more energy extends the battery life. And it is very important to get maximum battery life!

Now, if you drive exactly like the EPA, you get 40 miles. If you drive more carefully, you can go more miles on the allocated kWh of energy. If you drive like I do, it takes more energy to go 40 miles, so the engine will kick on before I get 40 mi.

BTY, I really enjoy reading your posts here at GM-VOLT.

GSP

Agreed. In fact I think I’ll splurge and put in two gallons.

“But I’ll live with it and realize that it is good that the Volt is an E-REV rather than a BEV.”

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Yes, you have two energy sources in the Volt. Your current car has only 1 unless it’s a hybrid like the Prius. I’m just not sure why people are always looking for a safety net against their own miscalculations and poor judgment. How difficult is it to keep a gallon of gas in the tank which will give you 50 miles, or enough to get to almost any gas station?

Agree generally.
Maybe half as much AER at 60 mph than at 30 mph.

I’m thinking (like I think that aerodynamic drag forces may be equal to all other drag forces (such as rolling resistance) at 30 mph, and the aerodynamic drag increasing by a factor of four between 30 and 60 mph. Things are of course complicated by the different start/stop patterns between city and hwy, but presumably the regenerative braking diminishes that aspect.

OK, maybe not Pike’s Peak. That would be asking too much.

“Easy” to do 40 every time. Just provide more than enough battery storage to:
1. cover off warranty related battery aging, and
2. 40 miles AER no matter what (almost), and
3. start the meter running when the batteries are full,
and then turn on the ICE at 40 miles every time, or some minimum SOC whichever comes first. Presumably the design would comfortably hit 40 miles first most times under a wide variety of driving conditions.

Per #21, the CDP just slowly creeps down over the life of the car to some minimum. After that minimum is reached, say after 3650 full charge cycles, it would be held, and the 40 mile AER number will start to creep down.

NO PLUG NO DRUGS NO SALE NO WAY =D——-