I had and Acer laptop, its battery "acted" the same.. It did not hold a full charge relatively quickly.
B-U-T, i mistreated my battery, for example, i would keep it plugged while on AC for weeks or days, even though it was fully charged..
If i remember correctly, Acer provides 3 months of warranty for their batteries, but i'm not sure.
You can use this tool if you want to check your battery's health:Battery status
Any how, if you ask me you'll probably need to replace you battery soon.. I Don't believe in any calibrations or other suggestions for "healing" the battery, BTW - Li-on batteries no longer have the memory effect, so that's not the case here.