A3 eTron Battery Capacity Questions

[avisriv]

The A3 eTron spec sheet shows a 8.8 kwh Lithium Ion battery pack. However it seems that the car only uses 6.2kwh to deliver the 20+- EV range that I am getting. Wondering if anyone has answers/explanations for three questions relating to this:

1. Why can't the car use the full capacity? or at least 80-85% of the capacity rather than just 70%.

2. Do the European model that advertise 30+mile ev range (under ideal conditions) use a different ratio? i.e. are they configured to use more of the 8.8kwh for driving to deliver the extra range? why can't we do that in the US? (software update maybe?!)

Interesting fact: in my area, using time of use pricing, I pay about 5.12 cents/kwh to charge at night - that translates to about 1.6 cents/mile (one-fifth of the equivalent cost with premium gas @40mpg). If I could get 5 more miles of ev range, I would hardly ever use gas at all! That's why I'm so curious about the 'lost' 30% of battery capacity.

 

[Dominic]

1+2: Could that be that rolling in north america call for colder temperature and some of the battery capacity is reserved to cope for cold mornings and additional heating?

The wait has been long for the e-tron to hit the american market. I red that Audi was working on getting things right in regards to climate.

I would bet the difference has more to do with module programmation than software update.

It might be just the way Audi wanted this car to work in a specific market. But... Sooner or later... If it is just coding... I'm confident there will be a way to code that car back to EU specs!

 

[bruintoo]

The A3 eTron spec sheet shows a 8.8 kwh Lithium Ion battery pack. However it seems that the car only uses 6.2kwh to deliver the 20+- EV range that I am getting. Wondering if anyone has answers/explanations for three questions relating to this:

1. Why can't the car use the full capacity? or at least 80-85% of the capacity rather than just 70%.

2. Do the European model that advertise 30+mile ev range (under ideal conditions) use a different ratio? i.e. are they configured to use more of the 8.8kwh for driving to deliver the extra range? why can't we do that in the US? (software update maybe?!)

Interesting fact: in my area, using time of use pricing, I pay about 5.12 cents/kwh to charge at night - that translates to about 1.6 cents/mile (one-fifth of the equivalent cost with premium gas @40mpg). If I could get 5 more miles of ev range, I would hardly ever use gas at all! That's why I'm so curious about the 'lost' 30% of battery capacity.

The ChargePoint at work always tops off at 6.5kWh to 6.7 kWh with the e-tron. I think maybe it has something to do with Audi wanting to always have 204 HP and 258 ftlbs of torque on tap available all the time?

 

[jerry3561]

As per one of my earlier posts from back in May, I have been charging the HV battery with approximately 7.5 kWh when empty.
Also, I don't think that the temperatures in North America differ significantly from those in Europe, so I can't see why they had to work on any "climate" issues.
I'm glad to see that e-trons are now rolling out in North America and can see that you are experiencing similar low temperature performance to the European e-trons.

 

[pkulak]

6.7 kWh at the wall with 90% charging efficiency is about 6 at the battery, vs 7 across the pond.

My top theory is US (California) vs European regulations. To meet environmental targets, EPA rated performance can't degrade for 10 years, which means the battery can't degrade for 10 years. It's why the Volt also uses less than 70% of it's capacity. It's both to keep the battery from degrading as much with the shallow cycling, and (possibly) to also open up capacity as the battery ages so that there is always those same 6 kWh available. Kinda sucky now, but at least we know we'll have tip-top-shape batteries in a decade...

My other theory has to do with some Audi guys a while back saying that they were tuning the car because they didn't think US customers would tolerate the engine coming on during EV mode. If it's true that the engine does come on in Europe, and it doesn't come on ever here (apart from kick down), it could be that they come out of EV mode a bit early here (to avoid too much voltage drop). Then, however, it would stand to reason that hybrid mode would deplete the battery further. I don't know if the battery continues to drain for a short period after EV mode ends, but that would be an easy way to test the theory.

 

[Dominic]

If your theory is deemed true, europeans will eventually see american range on their european car... I would be pissed off. That is false advertising.

 

[pkulak]

If your theory is deemed true, europeans will eventually see american range on their european car... I would be pissed off. That is false advertising.

Eh, all batteries degrade.

 

[Dominic]

You're right. But I like the "I garantee you at least that over the next few years" better than the "You'll get that at least a few times at first" approach!