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With a temperature change to 30-35F, my e-Tron battery charge of 80% is only giving me 142 miles which is 71% of the expected 205 miles. has anyone else seen a drop in battery performance with colder weather?
battery charge in colder weather
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I can't say that it's apples to apples, but I was used to 2.3 miles/kW at 75 mph in 110 deg F weather a couple months ago and today I was at 1.8 miles/kW at 65 mph in 55 deg F weather. It's not scientific but strange. I expect that the heat pump at 55 deg F is just as efficient as the AC compressor at 110 deg F. I wouldn't expect the resistance heater blocks to be on in the colder mode.
Completely normal, all EVs suffer reduced range in cold weather. 20-30% reduction is probably pretty much the average. Not helped in practice becuase you also tend to use energy-consuming accessories (lights, heater, wipers, screen defrost etc).
Yep, normal. It should improve as you drive and the battery warms.
Can you try garaging, charging and pre-conditioning prior to departure?
Those are steps I’d take when starting a road trip, or when range is important. Otherwise, no big deal.
Can you try garaging, charging and pre-conditioning prior to departure?
Those are steps I’d take when starting a road trip, or when range is important. Otherwise, no big deal.
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is this because the heater will be on? and by 20-30% reduction you mean as compared no heating on and heating on?
No, the battery efficiency and capacity is pretty strongly affected by temperature. Cabin heating is an additional loss. Batteries will take up maximum charge and will discharge with maximum efficiency at a temp of around 70F. Both of those drop as the ambient gets warmer or cooler.
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even when it gets warmer? I thought this was just a cold issue... makes sense now.... I checked a couple of cars in the summers and the range showing at 100% was less than what I saw a car today at 90% charge
in the summers the temp was about 110 F and right now the temp is 60 F. So I guess weather is the factor.
Yes, especially as it gets warmer! The falloff in efficiency/capacity is actually worse on the high-temp end of the plot, than on the low. That's why Audi put so much effort into thermal management for the battery.
The batteries will be a lot happier at 60F than at 110F
Based on the available data, charging the vehicle while it is in ambient temps this high, and letting it sit with a full charge in this type of heat are the worst things you can do as far as battery degradation.
If I were you I'd follow the 80% charge rule Audi recommends, and if you are charging to 100% for a trip or something, don't do it long before the trip. Set it up so it's only sitting at 100% for a few hours.
You might find this document of interest, particularly page 131:
https://static.nhtsa.gov/odi/tsbs/2019/MC-10155750-9999.pdf
At temperatures above 95 deg F, the car starts to actively cool the battery. I would think that would translate into an additional drop in mileage. (Elsewhere in the document it seems to say active battery warming does not start until the temp drops below 14 deg F--except during DC charging)
https://static.nhtsa.gov/odi/tsbs/2019/MC-10155750-9999.pdf
At temperatures above 95 deg F, the car starts to actively cool the battery. I would think that would translate into an additional drop in mileage. (Elsewhere in the document it seems to say active battery warming does not start until the temp drops below 14 deg F--except during DC charging)
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Yes my mileage exactly
Since August decreases sequentially from 196 at 80% charge to 160 now to 142 with same 80% setting
Weather 25-55 F
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As I start my second Wisconsin winter with my etron I always start charging as soon as I pull into the garage from a trip to start with a warm battery and keep a small heater going while charging.
Also aways try to charge in the daytime when the garage is warmer. I got a 162 mi 80% charge yesterday in my 35 degree garage.
Also aways try to charge in the daytime when the garage is warmer. I got a 162 mi 80% charge yesterday in my 35 degree garage.
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Yesterday I had about 25 mins of pre-heating and it was up to 1.8kwh/mi after a mile or so of driving (it was 24 out and it was about 37 in the garage). Drove 35 miles of mixed driving and averaged 2.4 kWh/mi. This was my first local trip on the 19" Audi winter wheel package vs. the 21" wheels. Looking back to last winter I was lucky to see 2.0kwh/mi on any trip, especially when the temps were below 30.
Was your preheating just the 30 minutes of heating by 1) starting it instantly through the MyAudi app, or 2) was it part of a Charge-and-Precondition timer set up through the MyAudi app to be completed by your departure time? I know the downside of "1)" is that it heats the cabin by pulling charge from the battery (while "2)" conditions the cabin by pulling charge from the wall), but if it really gets your efficiency up fast, I wonder if the trade-off in "lost charge by heating" is more than offset by getting to maximum efficiency more quickly.
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Most of the time it's not plugged in when I pre-heat via the app. Last winter I used the app to pre-heat on just about every time I drove it and used the MMI option any time I went into a store. Never kept track of lost range - it's all about comfort in the long Wisconsin winter.
It's so nice to get into a warm car! Having said that, my Q7 sat in the garage for most of the winter.
It's so nice to get into a warm car! Having said that, my Q7 sat in the garage for most of the winter.
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