I've looked a little to find this answer and was unlucky. Can you charge your liPo's the night before you use them? Wanting to know if I could save some time and start running as soon as I get to the track.

That would not be a problem.
Have fun at the track

Thank you

You are very welcome!

You can do it, many do. At the very least avoid high temps and temperature swings while charged.

But for the best performance, to keep the Internal Resistance down, it's better to limit time sitting at full charge. Since I quit charging ahead of time I've seen lower IR and better life span.

Others have reported more puffing issues over time with a lot of sitting at full charge, but generally for more than overnite.