Long time lurker, short time member, first time poster so be kind if this is a stupid or redundant question. I purchased the 29 w charger and cable at the Apple Store 2 days ago to take advantage of the fast charge. The Apple tech at the time told me it would make no difference. Based on what I had read here and elsewhere, I politely disagreed. When I returned the charger today because I found it cheaper(open box) at Best Buy, I was told not to fast charge often as it would fry my battery. Now the folks here seem to understand battery wattage ,trickle charge, etc. far better than I do. My question: was she blowing me smoke or is there some truth?