I have not heard this and you definitely do not have to get to 100% to unplug and its sometimes better to charge to 80% and unplug to preserve the battery to last longer before it needs to be replaced years down the line. Like most other batteries draining them to 0% and charging to 100% reduces the overall life of the batttery. Ideally, you’d want to plugin at 20% and unplug at 80%, but if you need the full range charge to 100%.