Hi all,
2015 TDI, battery replaced June 2021 by dealer (previous owner).

Couple questions:
1) can I have an auto parts store do a load test via the jump terminals?
2) can anyone give some guidance on the attached data from VCDS? The was car off / key on, drivers door open. The car sat yesterday for about an hour or so (spring cleaning) with the doors open, or opening and closing. Same this morning as I finished cleaning. Then it went for a few drives around town. Cold morning, at 18f and it cranked slowly.

Once it came back from Sunday errands, I ran VCDS. By the data, it wouldn’t surprise me if the battery was nearly toast. While running VCDS the battery light came on too, and it failed to start. It is now sitting with a charger on the jump ports.

 

The Q7 has a lot of electronics and auxiliary systems onboard and when you leave the key on all that stuff remains active. Same with doors open; the doors have multiple courtesy/puddle lamps on them using halogen bulbs for the most part, and doors open triggers dome lights on, etc., etc. Lots of energy consumption from leaving the key on.

Having battery drain issues is also quite common on these Q7s, either from failing, grounded sensor/switches (exterior door handles w/smart entry and lock buttons), as well as liquid damaged components, etc., as specific water leaks and clogged drains are common issues also.

Charge your battery properly and it'll likely be fine, if it's the OE, VARTA battery w/110Ah capacity. Those will last a really, really long time if you resolve the parasitic battery drains and keep them topped off either by driving longer distances regularly or a battery charger periodically, etc.

The remote jump terminals under the hood won't offer the best test results, as they don't give true voltage of the battery. My jump terminals typically read 0.2 Volts lower than the reading taken at battery terminals related to resistance loss in the cables, but your mileage may vary in that respect.

On mine, I had to flip the seat up to access the battery directly when I had mine tested, but that was for a battery warranty claim, etc., so it needed to be accurate.

With VCDS, pay attention to any fault codes related to grounded door handles if your car has push-button starting; there are separate codes for the proximity sensor and for the locking button on the handles, and those codes show in different areas of the scan data. Those faults are all constant, parasitic battery drains.

I guess the good news is the OE battery normally gives you a 4yr warranty on it. The bad news is that Audi Stealer probably won't honor it if you didn't buy the battery, and/or have the purchase and or W/O receipt for it. I ran into that scenario with one of our Q7s. The OE VARTA is a very good battery though. Folks who owned their Q7 since new often post of the battery lasting 6-8 yrs or even longer before they needed a new one. A lot of that is regular use of the car and trickle charging upkeep if it's not getting driven enough to keep the battery up.

 

Thanks for all that! No push button start, pretty sure no proximity sensors in the doors. Premium trim line (lowest?) So less bells and whistles.

Attached is the screen shot from this morning - looks far more normal. However, the charger threw a code of an open cell in the battery, so I suspect SOMETHING is going on. Battery is still technically under warranty for another 3 months, but it was done at a different dealer, and by the previous owner. I suspect they will pro-rate the warranty and I’d be stuck paying 90% of an overpriced battery.

The one thing that did look a bit off was the resistance in the battery yesterday, but better today. But again, how accurate that is to anything is anyone's guess.

 

If you got the service receipt for the battery install at Audi dealer, they'd most likely warranty it. No receipt, and you are probably out of luck unless happens to be same dealer that installed it originally, and that's still a longshot, IMHO.

The thing is, an Audi dealer is going to find some way to make money off you, such as charging you to run a diagnostic scan, remove battery from car/install fee, test the battery...etc., etc., so even if you have the receipt and they will honor the battery warranty, it could still end up costing you more than just buying a battery outright and swapping it yourself, etc.

I'd be looking for free confirmation that the battery will test 'BAD' before I'd spend too much time thinking about if Audi will cover the warranty. If it does test 'BAD', then you need to get a hardcopy of that test result, and if that's not possible take several pics of the individual testing the battery and results, etc. Then I'd call the Audi Stealer parts desk and see if I could just carry it in, have them verify it's bad and swap it at the parts counter. Most dealers did just send out service coupons in the mail, so you can ask about those too, if you'd rather drive it in and let them do all the work.

 

A four year old battery isn’t the hill I’m going to die on with the dealer. In the last year they’ve pulled the engine twice for a reseal and are about to replace the cat. I’ll just swap the battery myself if the local parts store confirms it has issues via a load test.

 

Good to hear.
I will say that the OE Varta flooded battery (110Ah) has an excellent longevity reputation, and my next battery I buy will definitely be the flooded type.

I really haven't had good luck with either of our Q7s swapping them to the AGM type battery in H9 size, which equates the the OE battery sizing/capacity. I got one AGM from Advance Auto parts, and the other Q7 I bought the AGM from Autozone. Programmed both into the BEM system, etc., etc., and on both cars have unplugged the external door handles related to the battery drain/fault codes for grounded handle sensors/buttons. I've had several of the AGMs test BAD and gotten them replaced by the auto store under battery warranty on the AGM (3yrs). Still, that's a big PITA to swap the battery every 1-2yrs, even though I'm really quite good at changing the battery now, lol.

I do think I've got the dreaded alarm system battery drain issue, which relates to water damage to the alarm component situated at bottom of the windshield plenum...just above the water drain that is known to clog and back-up, etc., so I've got a bit more troubleshooting to do in that regard, but just anecdotally from what I've read on here it kinda seems like Q7 owners have a lot more trouble with the aftermarket AGM (H9 size) car batteries. You don't want to buy an H7 or H8...those are just lower capacity batteries, but cost the same as the H9 sizing, which seem odd, but that's how they are priced. Auto stores will try to sell you what they have on the shelf...you need the big battery.

 

Ah, well, if you have had it at the dealer for that sort of work, it is very likely that the battery's issues are simply the result of prolonged low state of charge due to sitting. Like you said, though, probably not worth the hassle of arguing over it.