i have a lenovo 110 i3 i just got it and charged it to 100% and then unplugged it and let it get to 91% then plugged it back in and it saids on ac not charging so i unplugged it and ran it down to 89% then i tried it again and then it started to charge .My question is why is that? why wont my new laptop charge till im at 89% or less?thanks for any help..