The nickel-cadmium battery (commonly abbreviated NiCd or NiCad) is a popular type of rechargeable battery for electric-powered R/C models as well as portable electronics and toys. Active chemicals are nickel (Ni) and cadmium (Cd). In general, NiCd batteries have a lower capacity than nickel metal hydride (NiMH), alkaline or carbon-zinc batteries of the same size. For example, an alkaline or carbon-zinc AA battery is rated at 1.5 volts while an AA NiCd is rated at only 1.2 volts, making it somwhat underpowered for use as a primary battery in some appliactions. However, they are generally more robust and less sensitive to abuse and overcharging than NiMH batteries, and therefore don't require a peak charger.