New Battery Won't Power Laptop?


Sep 17, 2017
I have an HP Pavillion Dv7. About a year ago, the battery started to not hold a charge, so it would go from 100% to 0% in barely a half hour. So I went and got a new battery and followed the instructions on the package: charge for 4 hours, turn on and let it discharge until dead. It only made it to the 80's before it died. I tried to turn it on again, but unless it was plugged in it was like the battery was completely dead. Frustrated but short on time before moving, I returned the new battery and muddled along with the old one again.

So I just got another new battery and followed the instructions again. Once more, the battery lasted until 87% before dying, and now won't turn on unless plugged in. If I unplug the laptop immediately shuts off as if I don't even have a battery in.

Trying to find a solution online all I can find is "replace the old battery that's what happens with time." But these are two completely new batteries. Part of me wonders if the prior defective one got put back in the shop and I got it again (this one was sent to me from a different branch near where I lived so it's possible), but I can't be sure. My old battery doesn't have this problem, just drains fast. Help?
Are these cheapie aftermarket batteries, or "official" HP batteries you've been buying. Cheapie aftermarket batteries are often problematic.