car batteries...

[E21_Ross]

at the moment i just have a 'normal' halfords battery in my car:

http://www.halfords.com/webapp/wcs/stores/servlet/...

which is about 3 years old now and i'm looking to replace it. i've found this bosch one

http://www.alpha-batteries.co.uk/buy-online/car-ba...

but what is the difference between a heavy duty battery and a normal battery? the specs look identical between the batteries. and is there any harm in getting a battery with more power? say this one for instance:

http://www.alpha-batteries.co.uk/buy-online/car-ba...

thanks guys.