Thought I needed an extra battery for UK trip and purchased a "genuine" Canon BP-511A off EBay. It came with impressive original looking packing and plastic sealing.
It has charged in the original charger, but wont fire the 5D. Nothing.
The differences between this battery and the original are as follows:-
Darker grey colour
Painted words Canon Li-ion BATTERY PACK (Original charactors stamped into plastic case)
The initials RFP on rectangular recess on back of battery (Original has a small circular depression further recessed with no initials)
No number between longer contact strips on back (Original has 69C6 on mine anyway)
The two shorter, wider contacts are not quite as deep where they turn up the end of the battery and arn't quite as high.
Just thought I would throw this in and perhaps save someone else getting caught.
What really hurt with this is the original battery lasted all day with heavy use and was ample for my daily use anyway.
Nostalga ain't what it used to be
PPOK 'n welcome