Not all batteries are alike. Some are based on different technologies, while some are different sizes having been designed for specific applications. Some are rechargable while some are not.
“The nickel-cadmium battery (commonly abbreviated NiCd or NiCad) is a popular type of...Nickel-cadmium battery
“A nickel metal hydride (or NiMH) battery is a type of rechargeable battery similar to a...Nickel metal hydride