I was faced with exactly this dilemma a couple of years ago on my 2005 Focus.

In the end I opted for calcium, not silver-calcium. My understanding is that silver-calcium is better able to withstand high temperatures, but that this is not critical in this car. I have had no problems whatsoever with it in around 30,000 miles.

I found this:

"A Lot of companies will specify that their vehicles must use a Silver Calcium battery. This is not true, the only advantage that a Silver alloy gives above lead-Calcium batteries is an improved ability to cope with high temperatures generated under the bonnet. As long as the product is Calcium - Calcium then there is no cause for concern when fitting to a vehicle that requires a Silver - Calcium battery."

(from www.ukbatteries.co.uk/technical/faqs - no idea of how authoritative this is.)

See also: tinyurl.com/p2vq4f3 - which links to a pdf which seems a little more learned.

Edited by FP on 19/07/2014 at 15:51

Halfords offer both types. Navigate to the Battery section of their website; input your car's registration details and you should be offered a range of types and capacities (including lead-acid, which you do NOT want).

Edited by FP on 19/07/2014 at 17:16

I have bought two car batterys in the last 8 months, both were purchased from

performance batterys of tewksbury, delivered by courier the next working day

superb service and the best price ( Half the cost of a well known motoring store) and with a four year guarantee

check out their website & car battery finding tool, phone them if you have any questions

before ordering............ps they price match as well