Introduction & Audi A3 E-tron Battery Health

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DrT

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Hi I'm Neil from the UK.

Been using VCDS for a while but purchased a 2nd hand Audi A3 E-tron 2018. Which adds an extra dimension to the complexity of the old ICE engines as we now call them.

One question that is always being asked is the state of the health of the battery and can we tell it's capacity. My car was in for the 93H4 recall and I asked for a battery health check. The workshop manager and then the senior technician both spoke to me and confirmed that the battery was ok based on the cell balance. However they couldn't tell me what if any capacity reduction there was. They are looking into it and will get back to me hopefully. I think most things are governed by procedures now. However it does raise question if Audi/VW will replace a battery holding less than 70% charge, how will they know?

I've read the other posts and mainly Andy's maps from his car, which have been very helpful.

Values from 8C module show my cell percentage is between 94 and 95% charge when the car has a full charge.

The other information seems to be contained in the CAN Gateway 19.

Looking at the SOH_P and SOH_Q, I think this relates to the 12V battery as I think I've also seen it on my Skoda Octavia. Values below. Has anyone changed a battery and can confirm this?

ENG106155-ENG118436 EM_prcSoh-SOH_P 87 %
ENG106155-ENG118435 EM_prcSoh-SOH_Q 87 %

The most useful value I could find is

IDE09057 HV battery charge state 100.0 %
IDE09080-MAS08265 Energy storage unit-Energy content of HV battery: RWB-internal deduction 6825 Wh

also in the CAN Gateway.

Looking at this value, it tracks the driving range and percentage. When the ICE kicks in it reads 0 Wh and HV charge state was 1%.

Can anyone else read theirs and confirm if this is just a arbitrary value or dynamic based on the health of the battery. I know it doesn't confirm the reserved capacity.
 
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Andy

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Dunno if it helps but I did another full set of maps 2 weeks ago and my A3 e-tron is currently at the dealership having 93H4 done. Check out the fresh maps here:

 
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DrT

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Dunno if it helps but I did another full set of maps 2 weeks ago and my A3 e-tron is currently at the dealership having 93H4 done. Check out the fresh maps here:

Hi Andy

Very useful thanks.

I was wondering if the info in the CAN gateway was an arbitrary value as mine always reads 6825Wh on 100% charge. It's appeared at that value with a few different battery temperatures. It does deplete to 0Wh before the ICE kicks in giving a indication of usable Energy.

I noticed yours is

IDE09080-MAS08265,Energy storage unit-Energy content of HV battery: RWB-internal deduction,6425, Wh
with the charger reading
IDE09057,HV battery charge state,100.0, %

However your cell charge is at 95% and 96%, mine always reads 94% and 95% on full charge. Also battery temp ranging from 10degreesC to 25degreeC it always reads the same.

The dealer has not got back to me the info regarding battery capacity. I'm hoping the value stored in the CAN gateway might be dynamic and the best info I can find at the moment.

You don't by any chance a earlier reading at 100% charge of the CAN gateway?
 
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Andy

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I'll see what I can find but from a non-VCDS perspective when fully charged my car usually shows 24 miles of range but every once in a while when conditions are just right (recent driving with excellent 4.0 mi/kWh avg, warm temps, etc) it shows up to 26 miles of range (I saw 27 only once). Of course that's nowhere near realistic, the most I have ever gotten is 20 and change. But it does not seem to have degraded over the past 3 years and 16k miles.

Edit: this post may be of interest:

 
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DrT

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Having bought the car at 2 years old I have no idea of it's charging history. I can see that the car got plenty of connections but the trip hadn't been reset since the car was new and read 45mpg That'll be euro gallon at 4.54l per gallon. So I can assume if it was charged the ICE had been doing most of the work. Getting to the bottom of battery health is more an interest than a necessity, but I do plan on keeping the car for a long time, hence why I will call on the audi 8 year battery warranty if required.

My car shows 25 miles of range most days now that we are in colder weather, it was showing 26 previously and does show it now and again if I've had a good average. In the warmer weather it has shown 27. My commute to work and back is 22 miles, with a mix of heavy traffic and a few miles of what we call back roads which are 60mph limit but with twisty bends. Also a section of main road at 50 to 60 mph constant speed. I use the manual control to slow down for bends to get the energy recovery on the back road, but this section by far drains the battery the fastest and were I'm most likely to use the ICE if I don't think I'll get home with any battery remaining. Most days I manage and know I have to have 3.3mi/kWh to make it. I have no chance if I have to use the heater or AC. It's amazing how tight I've become with the heating :)

I've also read that my car has the worst options for range mainly 18inch alloys and the digital display dash.

I just wondered if the 6425Wh has been degraded over time or maybe a difference between regions for your car Andy and mine. Will keep an eye on mine and report back if I see any differences for everyone's interest.

Main thing is it doesn't sound like the batteries lose much if any detectable range. If we start getting 15 miles real world driving we'll all be queuing up at the audi dealers.

So next is to convince my work to install a charging point so I can use the car heater to get to work and back or stop being tight and use the ICE. Either that or move closer to work or buy the new model with 14kWh battery both more expensive options.
 
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Uwe

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So next is to convince my work to install a charging point
We gave Andy an extension cord to where he parks his car. Since we have 120V service, I think that only charges him at about 1 kW, but given that the battery capacity is less than 8 kWh, that's sufficient if he leaves it plugged in all day. :D

-Uwe-
 
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DrT

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We gave Andy an extension cord to where he parks his car. Since we have 120V service, I think that only charges him at about 1 kW, but given that the battery capacity is less than 8 kWh, that's sufficient if he leaves it plugged in all day. :D

-Uwe-
Such a good boss. Either that or you want to get 8 hours work out of him :)

My colleague had the Mitsubishi PHEV when they first came out. They let him run a cable out the window, that's until someone called it a trip hazard!
 
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DV52

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we have 120V service.
@Uwe : Probably one of America's worst decisions - IMHO!! Only good for the copper/aluminum industry (extra insulation is far cheaper)!!

Don
 
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PetrolDave

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@Uwe : Probably one of America's worst decisions - IMHO!! Only good for the copper/aluminum industry (extra insulation is far cheaper)!!
When paired with many installations actually being 60-0-60 installations it does have positive safety aspects - indeed the vast majority of building sites in the UK now insist that all power tools are 110V fed via a transformer (down from the nominal 230V) that actually produces 55-0-55, which has reduced building site electrical incidents.
 
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Uwe

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When paired with many installations actually being 60-0-60 installations
I'm not aware of any such installations. US residential electrical supply is 120-0-120. So we have 240V available for high-power things, and 120V for most everything else.

FWIW, our office has 208 3-phase, which yields 120V to ground from any of the three phases.

It's still a safety advantage over the 380-400V three-phase used in much of the rest of the world, that yields 230-240V to ground on any single phase.

-Uwe-
 
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PetrolDave

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I'm not aware of any such installations. US residential electrical supply is 120-0-120. So we have 240V available for high-power things, and 120V for most everything else.
Of course you're right Uwe - as I know from my stepsons house in MA (120V for everything except the washer and dryer in the basement).

I blame it on my fingers typing faster than my brain, and thinking about the 55-0-55 on UK building sites :mad: :banghead:
 
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DrT

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Well didn't have to wait long. Did a drive today which got the battery temp to 27degreesC from 15. Put it straight on charge on a 7kWh charger (I know it's restricted to 3.5kWh)

IDE09080-MAS08265 Energy storage unit-Energy content of HV battery: RWB-internal deduction 6900 Wh
Battery cells at 95% to 94% with a battery temp of 25degreesC (although this was about an hour after max charge was reached).

I have used this charger before and did check that it read 6825kWh.

So the value appears dynamic, but I wonder if charge rate and battery temp have something to do with the increase in reading.
 
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PetrolDave

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So the value appears dynamic, but I wonder if charge rate and battery temp have something to do with the increase in reading.
Cold batteries definitely hold less charge.
 
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DV52

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Cold batteries definitely hold less charge.
@PetrolDave Dave: 101% true - and let's not forget that if the car in question incorporates regeneration (I suspect OP's E-Tron has this), the energy management system MUST by definition allow a "headroom" margin below full battery capacity (so 100 % SOC never happens via traditional alternator charging)!

Don
 
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DrT

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Completely agree with temp altering battery capacity. Its just difficult to determine the exact capacity available on the e-tron for EV driving and if this altered under different charging conditions. However I am closer to assuming the parameter in the gateway is now dynamic and gives that value.

Cell percentage runs typically on my car from 95% to 20% on EV mode. Giving that 5% head room at the top for regeneration and 20% at the bottom.

So assuming 7kWH for EV mode would take it to the 8.8kwh capacity.

I checked a few times with battery temps between 10 degreeC and 25degreesC and it always read 6825wh. Starting charging at 27degreeC has lead to the 6900wh figure.

I guess time will tell if we can see degradation in battery performance from this figure. Which was ideally what I was looking for.
 
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PetrolDave

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The 20% "headroom" at the bottom is most likely to prevent deep discharge of the batteries, which if repeated would definitely cause loss of capacity.
 
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Uwe

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The 20% "headroom" at the bottom is most likely to prevent deep discharge of the batteries, which if repeated would definitely cause loss of capacity.
With Li-Ion cells, both deep discharges and time spent at "full charge" (max rated cell voltage) is bad for the cells. Since VAG gives a pretty good warranty on these batteries (8 years / 80,000 miles in the USA), they try to avoid both conditions. Check out the cell voltages when the battery is ostensibly "full" and "empty".

-Uwe-
 
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Andy

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This might have been my best EV only range. With 1 mile shown remaining 20.7 miles at 4.1 miles/kWh works out to 5.05 kWh on a battery pack ostensibly rated for 8.8kWh. Even if that last mile brought it up to 5.5 kWh that's still less than 2/3 of the total battery capacity actually being used.
 
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