I was sitting here working at home and was overcome by a plastic/burning smell and eventually tracked the smell to my charger. It was charging 4 batteries and when I took the batteries out one of the charging indicators was still blinking despite there being no battery in it. It wasn't especially warm, but the smell was strong. It's still strong even though the thing has been unplugged.
Needless to say, time to buy a new charger.
Needless to say, time to buy a new charger.