lithium ion car and motorcycle batteries

Here is a good read on reserve capacity and why it is an important consideration for choosing an automotive battery. Generally, the larger a battery physically is, the greater its reserve capacity. There are exceptions, but not many. I personally have always thought reserve capacity is the single most important factory to consider when choosing a battery. Most people go after a mega amount of cold cranking amps (CCA) but the truth is, you only need about 1 CCA per cubic inch of engine displacement. IMO, reserve capacity is much more important.

http://www.optimabatteries.com/en-us/experience/power-source/battery-reserve-capacity/