modality - a method of therapy that involves physical or electrical therapeutic treatment. rehabilitation - the treatment of physical disabilities by massage and electrotherapy and exercises.
Alkaline AA batteries are rated 1.5 volts, while NiMH AA batteries are rated at 1.2 volts. NiMH generally refers to a battery being rechargeable and to the materials from which the battery is constructed.
Typically, it may take 3 to 4 hours to charge any type of AA battery; however, all these depend on your requirements. Charging Time for Different Types of AA Batteries. Nickel-Metal Hydride (NiMH): Ultra Fast AA/AAA battery chargers take about 4 to 6 hours to simultaneously recharge four batteries. Conventional battery chargers may take up to 8 to 10 hours for charging two batteries.