so i bought an original bl-5j battery from a local store (i cant use a credit card right now to buy the scuds) and i noticed there are differences with the battery that originally came with the N900.

here are 2 pictures of the 2 batteries
left: the battery that came with n900
right:battery i just bought



the new battery (right one) has a small bump next to 3.7 volts is this something to worry about?



the new battery (right one) has an additional marking CE
and there are differences at the serial number.
Anybody can help me short this out?

P.S
sorry if I am posting kind of off-topic.