angrypengu

As most of you know, the D5 introduces some MHEV components, and top of mind for me is the 48V LI-ION battery that's beneath the trunk floor.

As we all know, batteries hate heat, and all of our collective summers are getting worse and worse. Parking a hot car in a garage in the dead of summer is worrying to me. Yes, there are ways to potentially mitigate this, including leaving the garage door open, or whatnot.

I've even been looking at garage ventilation options, or perhaps throwing the odd bag of ice packs in the trunk on a hot summer day.

My main issue is that once the car is off, the ventilation for the 48V battery stops, and when the car is baking in the hot sun or in a garage, that poor battery must die.

I know that the Audi eTron batteries and such are designed to last 8 (or was it 10) years and 160,000 miles. Audi has publicly stated this. That said, short of learning that the 10AH batteries in our cars are probably made in China, there's not much I have learned or found out about Audi design specs for these batteries.

That said, at $3500/pop and not covered after the new vehicle warranty, obviously, I'm thinking about what I can do to maintain these things as I'm owning the car outright. I accept this cost of playing this game but want to see if any of you are also thinking about how best to maintain this MHEV cars.

Or, if I'm really the only **** person on this forum, then I suspect this thread will die into oblivion, but I thought I'd ask because MHEV is only going to proliferate more. These cars are at P0, so we're just at the beginning of this hybridization.

Thanks!

derfA8L

gk1

angrypengu

Please do!! My garage temp gets to the same too!!

angrypengu

No..

Https://www.wardsauto.com/engines/continental-chinese-firm-form-48v-mild-hybrid-jv

angrypengu

To build on this I can confidently say it's not the Bosch battery because Continental is the supplier, for sure, for the BAS. While there are no public documents indicating who the vendor is for the 48v battery on our cars, all publicly stated documents from Audi indicates the battery is air cooled. The parts diagram references those ducting components too so the Bosch battery is out as it is passively cooled.

angrypengu

Also, just to add something here. The part # for the 48V battery is 4N0915105B

I literally wrote down back in mid 2018, the part number in CAD is $3519. Now in early 2019, based on Google searches, it's probably around $1500 CAD now, so not sure if anything has changed. That said, the purpose of sharing the part number is to see if anyone wants to help me locate the vendor of that battery. Based on the Continental link above, it's CALB--,high capacity lithium battery,EV car battery,Energy storage battery but I don't see any 10AH battery but that's probably because the JV between Continental and CALB = hush hush, so it's not publicly available.

My hope is to dig up that part using the part # and to try and figure out the supplier. In the meantime, hoping @derfA8L has some good luck with his dealer so we can learn a bit more about this battery.

Interestingly enough, in the Audi Canada 2019 warranty booklet, there is an actual paragraph on the eTron which states that the vehicle must not be parking >45'C for longer than a specified period of time (which I think is ridiculous because >45'C is easily the temp of most garages in the summer here)

Edit: I found CALB's USA link here: http://www.calbusainc.com/

It flat out states that their batteries start at 40AH, so...now I'm more confused than when I started this.

angrypengu

Take a look at page 18. Time to figure out which one is in our D5s!

angrypengu

My investigation into the cathode that is used in the 10AH battery, as well as who the supplier is, have been absolutely fruitless.

I'm just about to read this, and thought I'd share. It's the SSP for the 48V system, and more.

https://edoc.site/ssp0664aen-5-pdf-free.html

angrypengu

Bingo, although bad news. As per the SSP, the voltage of the MHEV is 3.68V. There are three types of cathodes, and the operating parameters and their pros/cons can be found in the paper attached. Start at page 11 of the PDF.

The only type of cells that support a 3.7V is NMC/Graphite, which as per the other PDF above, does not offer superior safety, or longevity, when compared to the other two cathodes. Audi states the MHEV system can generate 12kW of energy which is also inline with NMC/Graphite.

Perhaps not great news, but at least we have our info. There are some advantages though.

I quote.

"NMC/Graphite cells show a higher voltage of 3.7 V and therefore a superior energy density. The power is 6kW/kg (11kW/l). The good high temperature performance is shown in a storage test at 70 °C with SOC = 60 % where after 12 weeks 95 % of the initial capacity is retained. The advantages of this cell chemistry are the compactness through high power and energy density, the low cost per energy due to high cell voltage and common usage with HEV chemistry. Due to the incompatibility with the 12V system the preferred application is the 48 V dual battery (100-400 Wh, 8-12 kW)."