T480s battery drain

Hello fellow thinkers. Got\* myself a gorgeous 2nd hand touchscreen T480s a few days ago, still under warranty. The battery is at 90% capacity and "green" in vantage, yet drains in like 3 hours. It's a fully updated vanilla W10pro and I'm only running Firefox to be honest. I 've set max oomph at 99% to keep this black beauty sedated and nothing funky runs in the background as far as I can tell. **Any suggestions?** I used to own a T470s with the double pack and battery life was craaaazy.

​

*\*I had to outbid a few people, eventually paying what a brand new acer is worth, but wasn't feeling that cheap...*