. I have a 2007 Audi Q7. For the past 2 months I have had to periodically get my battery jumped. The other day I was driving and the car just quit. We bought a new battery, thinking that was the issue. It didn't solve it. The esp fault flashed on the dash. Where is a good place to start

 

You need to scan it, and with something better than a generic OBD2 reader.
Even without and check engine light on the dash, there are a ton of other codes your car is probably throwing that will lead you in the proper direction.

VCDS is the best, OBDeleven is cheaper and does what most people need.

 

Welcome to the forum! Always a good idea to post up your model year, engine type, and mileage, FYI.

All Q7s develop parasitic battery drains from their exterior door handle sensors/buttons; the car reacts very badly to low-voltage and throws codes across the control units. In most cars, testing alternator/charging system as good and replacing battery is all you do...no so on the Q7. The battery needs to be 'coded into the car', and it's best if you buy the factory/OE battery on this car too, which also has the code to interface with the car's BEM system, and tell it all about the battery. Then you have to go back and rescan the car completely and clear out all the many, many trouble codes it throws when the battery is disconnected related to low voltage sensed, etc., etc.

Even if you do all of the above perfectly, you can still find yourself with a dead battery again if you don't take care of the those door handle power-drain issues, as they are draining the battery 24/7, 365 days a year until you do. It's an easy fix though...see "Got Parasitic Battery Drains..." thread. You won't get very far though, if you don't get a decent VAG-(Volkswagon Auto Group) compatible diagnostic scantool. As noted prior, if you DIY get the VCDS cable setup ($200 for Ross-Tech Hex V-2). If you just need to clear and read the trouble codes, the OBD-Eleven ($60 on Amazon) is fairly cheap in it's basic configuration, which is all you need to read & clear codes...buying the programming access annual subscribtion on the OBD-Eleven is a waste of your $$, as it just has very limited access on the Q7 platform...believe me, I've tried.

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What do you mean code the battery to the car? I am not very knowledgeable on this.
It's a 2007 Audi Q7. 3.6 L with 218,000 miles. This is the first time I have had an issue with it in the 3 years I have owned it.

 

What size/type/capacity battery did you install?

Great cars, as is evidenced by your's at 218k miles and trouble-free for past 3 years.
Q7s do require specific processes when performing maintenance tasks, like changing the battery. The car monitors the battery state and charging system, and well, pretty much everything of any consequence on this car is monitored. So, if you don't manually 'tell the car' that you replaced the battery and what type of battery (wet cell, AGM, etc.), capacity (amp hours), etc., you installed, then the car's not going to know what you did, and it's going to keep doing what it was doing based on your prior old batteries age/parameters/etc. That means you aren't going to get the proper charging for a new battery unless you 'code' the battery into the car, which you do with a diagnostic scantool that speaks VW/Audi. Generic OBD2 scantools do not work with this car; you need one that is VAG-compatible, and it must support battery coding, etc.

Lot's of threads on here cover that topic ad-nauseum, as well as workarounds for coding non-OE batteries, and bypassing the BEM monitoring entirely. While you can get away with a generic battery (I have an H8 AGM in one car, and OE, wet-cell in the other), it's best to buy the OE battery rated for this car's voracious electrical appetite...it's huge, fairly priced, and has the amp hours capacity, and endurance to last 6-8yrs in this car, if you code it, and resolve the constant, parasitic drains from the door handles.

You can wade-in or get tips in the new member section on how to find topics; pretty much everything you could ever need is already documented. LOL, I killed a new H8 AGM battery in about 10 months with just a couple of grounded door handles; it goes a lot faster the more bad handles you have on the car. Good news is that's easy to resolve, and free...it does generate trouble codes though, so I sense a VAG-compatible scantool in your future.