Fast-charging high-performance NiMH rechargeable batteries suitable for various applications, including high-current devices such as cordless phones, radios, GPS receivers, flash units, remote controls, and watches. These powerful, rechargeable 1.2 V round cell batteries are designed for resource-saving use. The normal charge time is 16 hours with a maximum current of 100 mA, while the fast charge time is 144 minutes with a maximum current of 500 mA, utilizing minus-delta-U charge monitoring. These rechargeable batteries are specially developed to retain their charging capacity over extended storage periods. With very low self-discharge, they remain ready for use for weeks. Nickel-metal hydride batteries have been extensively tested for charge/discharge performance, high current, short circuit resistance, service life, and size.