The classic definition of a surge is a sudden over-voltage. That can happen when lightning hits your power line or something happens to your power transformer at the pole. A power interruption is a removal of power followed by restoration of power. Spikes can be generated during that time.
I don't see a problem with power interruption in relation to the battery itself. Your charger may not like being tripped off and back on, but an interruption is not much different than if you unplugged the charger and plugged it back in.
Most smart chargers go through an initiation cycle where the circuit is tested internally and declared healthy, then power is applied to the output. As far as the battery is concerned, every time you hit the fire button on your mod the battery gets a sudden load from the coil. That load can be anywhere from 2A to 20A, depending on your coil and the wattage settings.
I unplug my charger every time I have to leave the house for some reason. When I get back home, I plug the charger back in. That's not a problem. Lithium batteries aren't that fragile, but should only be charged when someone's around to monitor them in case something out of the ordinary happens.