I didn't know we were allowed to send batteries. We were informed not to handle battery issues over the phone because there are too many variables that could not be determined over the phone so now we are instructed to send the customer to an Apple Store where they have application or method to test the battery. There are times where we can determine given the exact information and iLog would notify us that the battery was indeed defective.
What's the point of phone support if your just going to send the customer to an Apple Store? Personally, I get irritated when AppleCare Reps recommend that as the first course of action. Mostly because the nearest Apple Store is some 160+ miles away. I generally cut them off.
This conversation happens every time I call for a mail-in MacBook repair, and is a complete waste of my time:
REP: Oh. Sure, we'll be glad to help you with that. I recommend you take your [insert product here] to one of our Apple Stores to have it checked out.
ME: The nearest Apple Store is 160 miles away. I would like you to send me a box.
REP: Ohhh ... OK. Let me check if we have any Apple Service Providers in your area.
ME: The nearest one is 50 miles away. I just want mail-in service.
REP: We have three Apple Service Providers in your state. One in [city that's 50 miles away], one in [town that's 45 miles away] and one in [town that's 200 miles away].
ME: Those are not exactly near me.
REP: OK. Well, we can do the mail-in service.
ME: Thanks.
As a consumer, your best bet is to do basic troubleshooting on your own depending on the issue (reset your PRAM, reseat your battery, use the hardware diagnostic test on your disk, etc).
I've used AppleCare phone support for user replaceable parts, mail-in repairs and on-site repairs. In all cases, they've been more than helpful.
I try not to waste AppleCare's time. So, I'm probably in the minority that tries everything before calling. I would say my average AppleCare phone time (after the Rep picks up) is maybe 10-15 minutes with most of that being on hold while they setup the repair/order.
My new favorite AppleCare perk is this:
http://www.apple.com/support/expert/. Your customer information and problem description pop-up on their screens. Very efficient.