Lithium chargers completely stop charging when the battery is full. Even if the charger remains plugged in, the battery will not be receiving power

That said, letting a lithium battery sit at 100% indefinitely is not good for it. If you can, reprogram the charger to fill the lithium to 80% instead, otherwise just let the battery sit at 100% as usual and just replace it after a few years when the runtime no longer is long enough for your application

I believe things are different for Lifepo4 which IIRC is more accepting of a float charge when full, although not ideal.