Batteries DC Power in a box
Everything has a purpose, this ethos lies at the core of our decision-making at Element 82 and batteries are no different. Cranking/Starting or high power/burst energy vs. Deep Cycle which is the term used for a discharge of energy before any recharge. That's the basis or starting point from there, capacity, expected life cycle, physical size, and layout considerations. There are so many options because batteries have so many applications.
Deep Cycle is used in house/service batteries in applications like a boat or motorhome when there is a sustained discharge from them before a recharge might occur overnight connected to mains or in a boat when the motor is started and recharge is provided via the alternator. Many brands of AGM batteries have a high power discharge capability, having said that it might only be 5-8 times its Amphour rating. So if a 100Ah battery refers to its ability to discharge 10 amps over 10 hours, it might also have a fast discharge capacity of 600 amps, referred to as 600CA (Cranking Amps). In these instances, while the battery might be classed as a deep cycle it has usable power for cranking. Numbers only get better when it's a 200Ah battery with 1200CA, you can see how this is sometimes why AGM batteries might be referred to as Dual Purpose Batteries.