I have run into a first "problem" with my MacBook. Sometimes, my battery is at like 90% then the next minute it would be like at 78% or so. Another instance, in like 5 minutes my battery was drained from 68% to like 31%. Then in a minute or so after that it would be like at 23%. My battery on my MacBook drains too fast. I have to keep my MacBook plugged in with the charger. It's not really a "portable" laptop anymore. Should I get a new battery? Thanks for the help.