AC Adaptor?

[Al Skierkiewicz]

Ed,
That is a still a chancy situation. In most cases the battery provides enough stabilization to keep the charger from producing higher than normal voltages. Keep in mind, though, that chargers still must output a voltage higher than the battery in order for charge current to flow to the battery.

Raptor9,
Please be advised that a simple rectifier fed from the line voltage still has the ability to place the supply at 110 VAC above ground depending on the way the electrical power is wired. Transformers of some type are needed to isolate the power line from circuitry that humans can contact.