48V System in NA Cars

[FBAnder]

I seem to recall this system effectively does nothing in NA cars but add weight. Is that correct? Does the 48v system start the engine or does the traditional 12v battery do this? If the former, what is the 12V battery used for? Maybe (probably) I am dumb but I haven't found much useful information on this when Googling. Thanks in advance!

[scsu]

I seem to recall this system effectively does nothing in NA cars but add weight. Is that correct? Does the 48v system start the engine or does the traditional 12v battery do this? If the former, what is the 12V battery used for? Maybe (probably) I am dumb but I haven't found much useful information on this when Googling. Thanks in advance!

You may want to search using "Audi 48V mild hybrid". Found some good videos (some right from Audi) and write ups that explain the system.

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[FBAnder]

The 48 V system in the RS6/7 and guessing RSQ8 doesn't seem to do any of that engine off while coasting stuff. It seems like it may function as an assist for the 12V system and helps with the 4 cylinder mode but that's about it.

[HL_Nya]

RSQ8 might be benefited by the active anti-roll bar.

[RMode]

NA as in North American, or NA as in Naturally Aspirated?

The 48v system runs, among other things, stop/start, cylinder switch on/off

https://www.enginetechnologyinternat...rs6-avant.html

[FBAnder]

NA as in North American, or NA as in Naturally Aspirated?

The 48v system runs, among other things, stop/start, cylinder switch on/off

https://www.enginetechnologyinternat...rs6-avant.html

North America

[BucksCtyMike]

You also see the 48v utilized is electronic anti roll bars across the audi range, although currently not in the RS6.


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[19_hole]

It also powers the electric turbo charger.

[HL_Nya]

It also powers the electric turbo charger.

i dont think RS6/7 doesnt have any electric turbos, only in 2.9T V6 in c8 S6/7

[S4-2-RS6]

i dont think RS6/7 doesnt have any electric turbos, only in 2.9T V6 in c8 S6/7

That is correct.

[icr]

I seem to recall this system effectively does nothing in NA cars but add weight. Is that correct? Does the 48v system start the engine or does the traditional 12v battery do this? If the former, what is the 12V battery used for? Maybe (probably) I am dumb but I haven't found much useful information on this when Googling. Thanks in advance!

Just a guess but it looks to me like it may be a full 48V Lithium system with a "spare" 12V battery & DC-DC converter to make it more user friendly due to the fact that no one will have capability to jump or charge a 48V lithium battery. Again, just a guess, but if the 48V lithium gets low, it could be charged back from the 12V battery. Then if the 12V battery gets low, it could be jumped or charged with conventional means.

[shammyh]

I seem to recall this system effectively does nothing in NA cars but add weight. Is that correct? Does the 48v system start the engine or does the traditional 12v battery do this? If the former, what is the 12V battery used for? Maybe (probably) I am dumb but I haven't found much useful information on this when Googling. Thanks in advance!

In the RS 6, the 48V system is simply to improve the start/stop operation; it serves no other purpose. The car is a 12V native system, so all modules/components run off 12V, not 48V. The only exception is the starter/generator itself, which uses/produces 48V. And there's actually a separate 12V starter that is used for the initial cold crank start.

In the S/RS Q7/Q8, the 48V system is also used for the active anti-roll bars, but that's about it.

Additionally, although some reviews mention the starter/generator adding hp/torque while driving, this is incorrect. The 48V system never contributes any power directly to the driveline.

So yes, unfortunately, it's pretty much just dead weight. 🤷

[BucksCtyMike]

In the RS 6, the 48V system is simply to improve the start/stop operation; it serves no other purpose. The car is a 12V native system, so all modules/components run off 12V, not 48V. The only exception is the starter/generator itself, which uses/produces 48V. And there's actually a separate 12V starter that is used for the initial cold crank start.

In the S/RS Q7/Q8, the 48V system is also used for the active anti-roll bars, but that's about it.

Additionally, although some reviews mention the starter/generator adding hp/torque while driving, this is incorrect. The 48V system never contributes any power directly to the driveline.

So yes, unfortunately, it's pretty much just dead weight.

Don't we have an electric AC compressor? I seem to recall that was also factored into the stop/start system, keeps AC system operating while engine is off.
That could have been another car though, not sure.


Edit: never mind, found the article, electeic AC compressor is in Audi’s future plans with the system.

[icr]

...
So yes, unfortunately, it's pretty much just dead weight. 🤷

Thank you for the information. I found one source showing the 48v battery to be only 10kg, so not too bad if that is correct weight.

[allenyao09]

In the RS 6, the 48V system is simply to improve the start/stop operation; it serves no other purpose. The car is a 12V native system, so all modules/components run off 12V, not 48V. The only exception is the starter/generator itself, which uses/produces 48V. And there's actually a separate 12V starter that is used for the initial cold crank start.

In the S/RS Q7/Q8, the 48V system is also used for the active anti-roll bars, but that's about it.

Additionally, although some reviews mention the starter/generator adding hp/torque while driving, this is incorrect. The 48V system never contributes any power directly to the driveline.

So yes, unfortunately, it's pretty much just dead weight. 🤷

Thanks for the information. I was under the impression that the 48V MH system should add some power. It could never shut off the engine when coasting. But I did hear a little bit of electric whining sound when gently accelerating. Thought that was the electric motor doing its work. I could be wrong.