I did mean the T480s, singular. The increased portability is valuable in my opinion, but I'll grant that it's a tradeoff. Replacing the built in battery is a 3

I did mean the T480s, singular. The increased portability is valuable in my opinion, but I'll grant that it's a tradeoff. Replacing the built in battery is a 3 minute job if you know how to work a screwdriver. (Literally just a Phillips.) Unless the battery is completely shot I'd argue that you should perhaps leave the OEM one, unless you know how to identify a genuine replacement.