battery charger

[Mart]

I don't think an old fashioned charger would drain the battery but I have a "modern" one which puts a light on when you connect it to the battery. This is with the plug not plugged in. When I plug it in the power light comes on and the light that was on indicates it is charging.
So would a charger flatten the battery if connected but unplugged?
Old fashioned charger: not sure but suspect not.
My "modern" charger: I think it would.
You "modern" charger: Don't know.

Not much help am I.

Best bet is to disconnect.

Mart.