Answers (2)
If you still have any sites open on your mac, it may be killing the battery, I'd just suggest turning your Mac off, sleeping mode is for when your gonna be out for about an hour or so and you can come back and get right on, your not suppose to always leave it on sleeping mode. Goodluck!
Well first the sleeping mode is made if you will just leave your mac on a very short period of time, second even if its in the sleeping it still consume your macs battery energy, third it can also be that your mac battery is starting to deteriorate that is why it is so easily to die so you might need to replace it.If that is the case you can look from here.