Question [Q] (Q) Asus Memo Pad hd7 battery issue.

Hi everyone. I bought ASUS memopad hd7 3 months ago and everything is smooth.
Problems is that since last week, everytime battery goes under 40% the tablet wont boot, showing red battery icon only.
I've searched fóruns for somekind of a fix with no luck at all.
Andy sugestions are apreciated.