btw what driver are you using
Li-ion chargers do not charge to 4.20v they charge at 4.20v +/- .05v.
I give away the LiitoKala lii (HKJ liked them) to people who aren’t even using NiMH — it’s a gateway drug charger.
Start them with a few decent NiMH and tell them to get good advice before trying li-ions if they ever want to.