QUOTE(earl-ku @ Dec 21 2016, 11:08 AM)
short start stop drive pattern?
maybe need to get a ctek battery charger and charge it every month or 2 weeks once
Mmm.. my daily drive consists mostly of around 20km of drive to work, and pretty much the same back home. At times, a bit more if I decide to avoid the main road due to traffic and the the scenic route. I rack serious miles with my mk7 too.
If it makes any sense.. when my stock batt died, I've owned the car for like.. a year +? Cool, since the car is pretty much almost a year old before I purchased it (let's not talk about VGM stock clearing here..), so the battery is pretty much, 2 years old, roughly. So I had the car towed to my dealer, claimed warranty, no prob, done.
However, the replacement battery lasts less than 6 months - I got a bit annoyed, and just outright ordered a Varta AGM from Varta Malaysia (which is technically just as expensive as the inferior stock EFB, if I had to purchase it at my dealer). Still holding up so far, fingers crossed.
So I've been talking with other owners overseas.. and from what I can gather, mk7s, or any current VW with Start&Stop; has battery management module, along with EFB/AGM batteries - these needs to be coded every time a new battery is installed. They argued that, over time, as the stock battery degrades, and the alternator would increase the charging rate, to compensate. When a new battery is installed, without coding the battery management module, the alternator would just overcharge the new battery gradually, and boom, dead, new battery.
It's all pretty much speculation and discussion among owners.. though I've 2 friends, with the exact issue. I've hooked them, and my cars to VCDS and found stock codes in the battery management module, although it's supposed to be coded/changed upon installation of new battery. And all 3 cars just died suddenly one day, w/out the usually Low Battery warning, previously like with the stock battery - as in the car didn't know a new battery was installed, and not sure about the correct State-of-Charge. So I came to the conclusion that my dealer didn't code my car (or my friend's) after the battery claim, perhaps on the expense that none of the previous VW cars here needed to do so..? It's not like dealers know everything or as meticulous as they're supposed to be, aye? My mk7 was even delivered to me at first day, with the tires 20psi more than recommended rating.
Pretty much X-Files conspiracy and all that.. anyone is welcome to chime in their opinion. I've bought the Ctek Ct5 Start/Stop, too, just in case, anyway. It's fine if it's other VWs - I can just go around the local battery shop and buy a replacement. But there's no EFB/AGM that can fit the mk7 sold locally here, so.. yeaaa it's a pain. But since batteries are only warranted for 2 years, I've taken the liberty to advise my fellow local mk7 owners to just straight up swap to the Varta AGM, instead of buying a pricey, inferior EFB from the dealer. My dealer, at least..