Hold Mode Acting Like Hybrid Mode

[LuciaAri28]

Over the last few weeks, I didn’t get much of a chance to charge my A3 E-tron, so I’ve been using Hold Mode to save battery, trying to recuperate as much electricity as possible while driving.

What I’ve noticed is that when I start driving after a stop, the electric motor is still being used for smooth acceleration. The engine only kicks in after a bit of time, which makes it feel more like it’s in Hybrid Mode rather than Hold Mode.

Is this how Hold Mode is supposed to work for everyone, or should I be concerned? I’m going to see my dealer soon to pick up a new EVSE, and I’m wondering if I should mention this to them while I’m there. Any ideas?

 

[cmc]

Hey there, the ICE does not have its own starter it relies on forward motion of the car by the main electric motor to drag start the ICE. Appreciate the creativity in packaging so much into such a small car!

 

[cmc]

Oh and the ICE has to run for 30 secs or so to warm up before it is allowed to drive the car...

 

[THICColasCage]

Hey there, the ICE does not have its own starter it relies on forward motion of the car by the main electric motor to drag start the ICE. Appreciate the creativity in packaging so much into such a small car!

Oh and the ICE has to run for 30 secs or so to warm up before it is allowed to drive the car...

Nice, can you go into any more detail - I'd like to learn more.

 

[etronfan]

Nice, can you go into any more detail - I'd like to learn more.

YouTube Chanel funcarreviews has a lot of info on this car

 

[bros225]

Over the last few weeks, I didn’t get much of a chance to charge my A3 E-tron, so I’ve been using Hold Mode to save battery, trying to recuperate as much electricity as possible while driving.

What I’ve noticed is that when I start driving after a stop, the electric motor is still being used for smooth acceleration. The engine only kicks in after a bit of time, which makes it feel more like it’s in Hybrid Mode rather than Hold Mode.

Is this how Hold Mode is supposed to work for everyone, or should I be concerned? I’m going to see my dealer soon to pick up a new EVSE, and I’m wondering if I should mention this to them while I’m there. Any ideas?

I think your car is working as designed. In "battery hold mode" your car is still a parallel hybrid (e.g. Toyota Prius). The electric motor and the ICE work together always. The battery power is obtained by regenerative breaking and I have a suspicion (but I can't verify it) that the ICE also provides some charging. Your MMI display and tachometer show you when the engine is on or off. "Hybrid" mode is a little different. It makes your car behave as a typical hybrid as I described above, but adds the bonus of using your stored battery power (the power you add when you plug in). I like to think of this as "super hybrid" mode. This mode gives you better mileage than "battery hold mode" because it is utilizing more electric power than a standard hybrid engine. After the stored battery power is used up, the car goes back to being a standard hybrid.

 

[Kenny1678]

I think your car is working as designed. In "battery hold mode" your car is still a parallel hybrid (e.g. Toyota Prius). The electric motor and the ICE work together always. The battery power is obtained by regenerative breaking and I have a suspicion (but I can't verify it) that the ICE also provides some charging. Your MMI display and tachometer show you when the engine is on or off. "Hybrid" mode is a little different. It makes your car behave as a typical hybrid as I described above, but adds the bonus of using your stored battery power (the power you add when you plug in). I like to think of this as "super hybrid" mode. This mode gives you better mileage than "battery hold mode" because it is utilizing more electric power than a standard hybrid engine. After the stored battery power is used up, the car goes back to being a standard hybrid.

Not just suspicion, but fact. Using an OBD tool to monitor battery current while driving, after cranking over the ICE, even while accelerating you will see the battery regain some charge. It seems like it will use some charge, then use the engine to recover almost all of what it used. Also, if you regenerate a lot while in battery hold, say by going down a long hill, it will choose to use up that charge immediately after.

From what I can tell, being in "D" battery hold, the car will choose to let the battery drain slightly if it thinks it will be more efficient. In sport mode, the car will always choose to increase the overall battery percentage instead of decreasing it (of course using the electric power during acceleration) at the cost of efficiency.

In general, this seems like normal behavior and the pattern of your driving will greatly dictate how well "hold" mode actually holds charge. On a flat and level highway, you will see absolutely no change in charge, but in city traffic or a hilly highway you're likely to see the charge decrease slowly over time.

 

[cmc]

Also the 30 seconds or so when the ICE is drag started and is in its warm up phase it is actually charging the 12V so not totally wasting the energy... I don't know if it also charges the HV battery. Toyotas have an extra motor to start the ICE. The A3 does not... A single propulsion motor does everything. AC is electric, so is water pump, brake assist, steering, cooling fan etc... Fantastically elegant design. I think in S mode if the battery is completely drained it will actually do some charging so that some boost is available.

 

[Kenny1678]

Also the 30 seconds or so when the ICE is drag started and is in its warm up phase it is actually charging the 12V so not totally wasting the energy... I don't know if it also charges the HV battery. Toyotas have an extra motor to start the ICE. The A3 does not... A single propulsion motor does everything. AC is electric, so is water pump, brake assist, steering, cooling fan etc... Fantastically elegant design. I think in S mode if the battery is completely drained it will actually do some charging so that some boost is available.

Looking at this snippet from the A3 e-tron Audi self-study program, it doesn't "drag start" the engine, but rather connects the electric motor to the engine to get it up to speed before starting combustion. It does feel like a drag start because you can feel the sudden loss of power as the ICE engine is being spun up.

Also, the 12V is always being charged by the HV battery, which can be seen with the "generator current" value you can see on the gateway module when using an OBD tool and the "Car Scanner" app. It's surprising how much current the car pulls (around 40A) when idling.


This page provides a lot of info on the drive modes, but doesn't really answer all the questions.

 

[dlinkA3]

Looking at this snippet from the A3 e-tron Audi self-study program, it doesn't "drag start" the engine, but rather connects the electric motor to the engine to get it up to speed before starting combustion. It does feel like a drag start because you can feel the sudden loss of power as the ICE engine is being spun up. We have never felt any loss of power as the ICE is started in our 2017 A3 e-tron. It is the smoothest PHEV we have ever driven, and I have driven many for Electric Vehicle events in California.

Also, the 12V is always being charged by the HV battery, which can be seen with the "generator current" value you can see on the gateway module when using an OBD tool and the "Car Scanner" app. It's surprising how much current the car pulls (around 40A) when idling, but the voltage is no higher than ~12.6V, which is not sufficient for providing power to refrigerators in a towed trailer..

This page provides a lot of info on the drive modes, but doesn't really answer all the questions.

 

[bros225]

View attachment 55Looking at this snippet from the A3 e-tron Audi self-study program, it doesn't "drag start" the engine, but rather connects the electric motor to the engine to get it up to speed before starting combustion. It does feel like a drag start because you can feel the sudden loss of power as the ICE engine is being spun up.

Also, the 12V is always being charged by the HV battery, which can be seen with the "generator current" value you can see on the gateway module when using an OBD tool and the "Car Scanner" app. It's surprising how much current the car pulls (around 40A) when idling.

View attachment 56
This page provides a lot of info on the drive modes, but doesn't really answer all the questions.

Wow! Thanks for the awesome documentation.

 

[bros225]

I might add about battery hold mode: although it is designed only to maintain the battery power that you stored while plugged in and not to accumulate power, I have had one or two occasions where I did accumulate enough power to be able to switch back to EV mode for a short period of time. This happened after a long downhill with breaking.

 

[PHEVophile]

I think your car is working as designed. In "battery hold mode" your car is still a parallel hybrid (e.g. Toyota Prius). The electric motor and the ICE work together always. The battery power is obtained by regenerative breaking and I have a suspicion (but I can't verify it) that the ICE also provides some charging. Your MMI display and tachometer show you when the engine is on or off. "Hybrid" mode is a little different. It makes your car behave as a typical hybrid as I described above, but adds the bonus of using your stored battery power (the power you add when you plug in). I like to think of this as "super hybrid" mode. This mode gives you better mileage than "battery hold mode" because it is utilizing more electric power than a standard hybrid engine. After the stored battery power is used up, the car goes back to being a standard hybrid.

I always use battery hold for highway trips, as it retains the power (electric mileage). I still get better mileage than I did in my most efficient ICE vehicles. I never use the hybrid mode, I don’t find it useful, it uses up the electric range too quickly. Around town I use pure electric. I have had long term mileage lower than 1.8 litres/100km. I don’t live in a large city.

 

[PHEVophile]

I always use battery hold for highway trips, as it retains the power (electric mileage). I still get better mileage than I did in my most efficient ICE vehicles. I never use the hybrid mode, I don’t find it useful, it uses up the electric range too quickly. Around town I use pure electric. I have had long term mileage lower than 1.8 litres/100km. I don’t live in a large city.

Yesterday, drove about 300km on battery hold, at speeds of 80 to 120 km/hr (mostly 120), and my consumption was 5,9 litres/100km (39.86 mpgUS). And that’s with the rolling resistance of snow tires! I’m pretty happy with that.

 

[Nuje]

The 1.4T in these cars is indeed a pretty good engine - excellent combination of fuel economy as well as pretty decent get-up-and-go.
Our fuel economy on highway trips (typically up/down Vancouver Island) yields pretty close to the same 5.9L/100km - rarely been over 6.0; had it as low as 5.6L (favourable winds that day).

 

[cmc]

I bought this car with the full expectation that the 1.4T was going to be used and not a boat anchor. A lot of critics of PHEVs say that the gas engine is lugging around a big heavy dead battery.... They forget that the inverse is also true...