Apple engineers are in the process of contacting iPhone 4S owners in order to determine the cause of alleged battery life issues. One iPhone owner told the Guardian that Apple engineers “installed a monitoring program” on his iPhone to diagnose the source of the problem:

“I then got a call from a senior [Apple] engineer who said he had read my post and was ‘reaching out’ to users for data and admitted this was an issue (and that they aren’t close to finding a fix!) and asked lots of questions about my usage and then asked if he could install the file below and that he would call back the day after to retrieve the info. I extracted the file from my Mac after a sync and emailed it to him. He was incredibly helpful and apologetic in the typical Apple way!”

The unnamed iPhone user was apparently experiencing a “10% drop in standby every hour”, he turned off location services and Siri in an attempt to troubleshoot which new features exclusive to the iPhone 4S might be causing the battery loss to no avail. We first reported about users complaining about the iPhone 4S’s battery draining unexplainably fast a couple weeks ago. The issue seems to only be affecting a small number of users, although the Apple discussion boards are still full of people experiencing similar problems. If this account with an Apple engineer is to be believed, it looks like Apple is at least acknowledging the issue even if they “aren’t close to finding a fix”. We’ll keep you posted as we learn more.