I needed to replace the battery on my spec C and had a bit of a search around on here. One of the recommendations is a Braille Autos racing job which looks great if you want an even smaller, lighter battery.

But I was after a direct replacement and found this site: Car Battery Car Batteries Sealed Car battery - Performance Batteries and bought the 054 model. £50 including delivery next working day and a perfect match in terms of size and rating.

Well recommended if your battery's on its way out.

 

Pretty low though at 340 cranking amps mate.. will that be enough?

Admittedly its a little more but an Oddysey PC680 is only 6kg and has 680 cranking amps. Can be had on fleabay for about £80

 

One of the guys in South Wales has one of the small Alphaline ones in that link on his Spec C, don't think he has any problems with it and it was sold/recommended to him by Powerstation. I'm planning on getting the 053 for mine (same battery but with the larger terminals)

 

Fair enough..

 

i found a direct replacement in halfords.