My macbook had been suffering lately - more than 600 recharge cycles on the battery, less than an hour of runtime for basic browsing etc.
Repair was super easy (just swapping out the battery). Purchased a "Stock A" battery that arrived in mint condition with only 4 recharge cycles logged on it, at a significant discount from buying a new battery from Apple. Battery health is now 100% as opposed to the 45% I had been clocking in.
Check with iFixit for one of these OEM batteries in stock before going 3rd party or buying direct from Apple.