I have a 2017 Q7 Prestige bought on May 2016. It's been 10 years but I have driven only 60K miles. The battery still seems fine but the question is, shall I replace the battery proactively or wait for it to show some sign of wear. I would like to hear from the members on when and why they replaced their battery on their Q7.
TIA

 

I was in the same situation last year with about 65k on my 2017 Q7. I replaced it proactively, but was not having any known issues. The original battery was a Varta, which last very long, but may also be since the battery in most German cars is located away from the engine compartment ( had a relatives original Varta battery that lasted 22 years). I bought my replacement from Costco, but needed to make sure it had the proper three designation code. Original battery was 850 CCA, replacement was 900 CCA. Independent shop installed and reset battery monitor. When I test the new battery occasionally, it shows around 75% charge. Next time I’m at dealer I may have them recode/reset battery monitor.

 

Didn't you try to replace the battery with the original Varta one? I usually replace only with OEM items especially on my German vehicles.

 

I replaced mine at 7 years when I noted the auto start/stop no longer worked. New battery corrected that.

 

It'd be nice to think all car batteries are built the same, but they are not, even when built in/by the same factory. Varta batteries last longer due to the specifications they are built to internally exceed those of pretty much all other battery brands, and in addition, the Varta batteries generally use advanced electrolyte compounds not found in the typical 'name brand' batteries sold on the aftermarket, etc. It's better build quality and better chemistry combined that make them last so long, and yeah, the BEM system helps to maximize their life-cycle as well. That's why it so important to reset/recode the BEM properly when you change a battery out, and especially if switching to a non-stock battery. LOL, ask me how I know.

If you look up who actually manufactures car batteries, there's really only a handful of factories around the world, and just a couple remain in North America, but they make ALL of the diff store brands you are familiar with. Advance Auto Parts bought the Die-Hard brand name back around 2019 or so, but it's important to understand they don't sell the 'OG', Die Hard batteries formulations/specs. Rather they sell their own batteries under that brand name now as being their store brand, but still order the batteries to meet their own custom specifications from a battery mfg, and then plaster on the Die-Hard brand labeling.

Most important thing for battery longevity on these Q7s, IMO, is to source the correct sized battery/type, program the BEM correctly, and ensure that you don't develop parasitic battery drains over time, which can be from the fancy Audi door handles proximity sensors or lock buttons grounding out, etc. Grounding cables in the engine compartment are also prone to internal corrosion as they age, and sometimes electronic components just get fried, whether from known water leak points or clogged water drains on these cars or just unfortunate circumstances. Be sure you understand the 'known issues' for your year of Q7, as there are likely to be quite a few that create problems with the electrics as these cars age, if left unattended to.

Water drains in my plenum got clogged at some point prior to purchasing the car, and moisture entered the alarm module located near bottom of the plenum area, which then eventually turned into a major parasitic battery drain whenever the car alarm system was active. All of my proximity sensing 'smart' entry door handles grounded out and had to be unplugged inside the door to stop their parasitic drains. FYI: Unlocking the doors still works fine; just gotta tug on the handle and it unlocks. Anyhoo, it'll happen with age, so just be aware of the common known issues with your platform and year model, etc.

 

I am facing the same issue. My 9 year old Varta is at 42% so I am starting to think about it. Anyone know where I can buy a Varta replacement OEM battery from? Given how good the OG has performed, I'd like to get the same.

 

I think everyone is getting too hung up on "manufacturer". All of the different name brands you see in the store are almost all made by 1 of 3 companies. The largest, Clarios (formerly Johnson Controls), manufactures the Varta batteries and a third of the whole market, for that matter.

In my opinion, buy the battery with the best warranty. Since there's a VERY high likelihood that the two batteries you're looking at from two different brands at two different retailers are essentially the same thing, the warranty will set them apart. My 2 cents.

 

I replaced the original battery in my 2019 last fall preventatively. It was fine, but on borrowed time. I bought an AGM at Walmart after extensive research. Made by Eastern Penn Manufacturing and has a 4 year warranty. Coded the new battery with Carista using the code EPM as the manufacturer. So far, so good. If it fails, I can take it to any Walmart in the country for a replacement within 4 years. Not prorated either. The only two things I buy at Walmart are oil and batteries.

 

My suggestion is to proactively change it. For you to have gotten 10yrs. I think is VERY lucky. From what I hear from others there's usually no indication that the battery is about to go IT JUST GOES!!! Just my 2cents on the matter. Good luck

 

Getting it replaced tomorrow with OEM Varta.