"NiCd" refers to a battery that contains nickel cadmium as its chemical base; other abbreviations include "NiCad" and "Nicad." It is the first type of portable rechargeable battery produced and is still widely in use in power tools and cameras.
"NIMH" refers to nickel metal hydride; it's an updated and better version of a NiCd battery. It has more power and doesn't need to be fully discharged regularly, unlike a NiCd battery. It operates well in digital cameras, motorized children's toys and cordless telephones.
"Li-Ion" and "LiPo" batteries refer to lithium ion and lithium polymer respectively. They are the latest versions of rechargeable battery and produce three times the voltage of a nickel battery and last three times as long. They are widely used in cell phones and, laptops; LiPo in particular is the favorite battery for remote control enthusiasts.
"SLA" means "sealed lead-acid" and is the battery you probably have in your vehicle. It's a sealed unit meaning no maintenance is required; it produces 12 volts and about 50 amperes of current.
"AGM" stands for "absorbed glass mat" and is the latest technological advance in vehicle battery design. It doesn't contain any fluid; it is completely safe if the casing gets damaged. AGM batteries have very long shelf lives; they can withstand freezing temperatures and long periods of inactivity.
The term "mAh" means "milliamp hours"; it is on most rechargeable battery labels. It refers to the amount of time you can expect a fully charged battery to last. For example, if the battery label states "2,400 mAh," it means the battery can power a device that uses 2,400 mAh for one hour.
You see the letters "CCA" on most car batteries. It means "cold cranking amps" and is the power the battery can generate to start your car on a cold day.
"V" means "voltage"; it's the force of electricity from the battery to the device it powers. "Ah" means "mpere hours"; the same as "mAh," except 1 Ah is equal to 1,000 mAh. "CA" means "cranking amps" and is usually labeled on deep-cycle batteries used to power golf carts and wheelchairs, where CCA is not so important.