We use a smart charging chip from Texas Instruments inside the light, this communicates with your charger and negotiates for higher charge power, while monitoring the battery. If you plug into a slow charger, it will charge slowly. A fast charger like a 5V / 3A or QC3.0 rated one will charge the lights fastest. If you plug in a massive 100W PD charger or something, the light will just limit the max current to 3A into the battery, to protect both the charger and the light, so you can't possibly blow up the light or damage anything with the "wrong" charger because the light controls those limits. As a result, this means you can leave it plugged in indefinitely after it's fully charged and it won't "over-charge" or cause issues. Basically: just plug it in and leave it, it'll do the rest and be completely safe.