I have an Asus ROG strix gl502 gaming laptop that is about a month or two old. It's supposed to have 3 and a half hours of battery life but lately it's only had 1 and a half on full charge. I have been doing things such as updates, downloads and gaming and sometimes I have to plug it in while doing these things because the laptop needs charging. Have I killed my battery? or have I just got a dud. It never lasts 3 hours at all anymore.