Does Applecare cover mbp's battery replacement or you have to pay for it?Yes,
the cost of a single repair will far outstrip the cost of applecare.
The only reason why I may not purchase applecare for a MBP, is that I plan on selling it after year 1 which is not generally the case for me.
Batteries are not covered by warranty or AppleCare, except in the case of manufacturing defects.Does Applecare cover mbp's battery replacement or you have to pay for it?
AppleCare Protection Plan:This warranty does not apply:
(f) to consumable parts, such as batteries, unless damage has occurred due to a defect in materials or workmanship;
b. Limitations. The Plan does not cover:
(ix) Consumable parts, such as batteries, except in respect of battery coverage under APP for iPod or unless failure has occurred due to a defect in materials and workmanship;