All 012 car batteries use 12v of power and have a length of 207mm, a width of 175mm, and a height of 190mm upwards. All batteries of this size will fit cars with battery bays of these dimensions. Yet the one you choose should depend on the conditions to which you expose your car. You should also consider whether or not your car is capable of benefitting from the power that different types of 012 battery provide. Lead acid 012 batteries are essentially standard, like-for-like replacements for those found in most cars when they leave the factory. They usually last for up to 20,000 starts. Calcium-powered 012 batteries are the next step up in terms of power and lifespan. This type of battery will allow you to start your car around 30,000 times, whereas an absorbent glass mat (AGM) battery offers up to 50,000 starts. If you have trouble starting your car on those cold winter mornings, you may benefit from the extra cold cranking amps (CCA) that these higher-grade batteries offer.