Various car battery sizes

There are various car battery sizes to suit different types of motor vehicles. Some are customized to specific climates or engine types. You can’t put any old battery into your sports car. Some batteries require maintenance on a regular basis, i.e. adding water. Others only require you to check once in a while to see if any gunk has congealed at the top of the batterey. The good thing about modern cars is that a lot of the newer types tell you how charged your battery is. Things can also go wrong that cause you to have a flat battery, such as alternator failure. This of course has nothing directly to do with your car batterey, but it will cause it to decharge fully.