New macbook pro battery randomly took longer to charge last night

Hi guys,

I recently got my macbook pro battery replaced and a brand new charger. I also had diagnostics run on my computer and they all came back fine. The battery life is as expected for a machine this age and it worked for the first two weeks or so just fine, but then last night overnight I woke up and realized it had randomly taken 3 hours to charge from 40 to 96%....I'm using it now and the battery isn't draining any faster than usual, and it's condition is also normal, I checked. It also seemed to be charging faster when I woke up it up, and slower when I put it back to sleep. This only happened once so I am going to reset the SMC/PRAM and see if that helps, does anyone know if flukes like this happen and why, or if something else is wrong with it?