We have a 2013 QX56 that we purchased in 2018. This has been a great car and we take good care of it ie all fluids changed regularly, anything makes a sound gets fixed etc...
We noticed within the first year and every year since that this car eats batteries (On battery 5 since 2018). Meaning, within a year the battery no longer has cranking amps and needs to be replaced. I am not sure if this is related to the starting issue or not - but randomly, could be 6 months, could be a week - but ALWAYS when my wife has the car with the kids she gets stranded...the car just wont start. Most times, I can get it to either start itself (after multiple attempts of cycling through start acc and off) or jump it to get it started. This all depends on the dome lights inside - sometimes they are very dim or completely out and I know it is battery related. Other times when the lights are bright, I know something else is going on such as going through the security protocol of closing all doors unlocked, putting the key in the door to lock, then locking with the fob, then unlocking with the fob and getting in and starting - sometimes this works and is probably something to the degree of my kids flipping the locks in the backseat to get out instead of waiting for my wife to unlock. However, 2 days ago it wouldnt start and the yellow light was on for the key. I changed the battery in the key fob and that didnt help but the car wouldnt even try to turn over. So I pulled the battery terminal off and waited 30 seconds and put it back on which allowed the starter to at least engage - I then jumped the car and took it immediately to Infinity.
We had Infinity run a draw test overnight last night and they said nothing is drawing power on the car when it is off. I initially thought was the starter was sounding worn out so I replaced that 3 weeks ago - 2 days ago was the first instance of the no start since. Infinity could not find any issues and just said maybe it was related to the intelligent charging feature and said sometimes when these cars get older that system acts up - so they disabled it. That was all Infinity could figure out - just a hunch.
So to sum it up - I am having a random no start issue sometimes battery related, sometimes not. There is no draw on the battery and now the intelligent charging system has been turned off. The starter is new and the battery is as well. I swear I am losing my mind trying to figure this out - please help!