Cordless Phone Batteries
About Cordless Phone Batteries
Cordless phone use general purpose rechargeable batteries or batteries specifically designed for each cordless phone model depending on its power consumption. Most of the phones use Nickel Cadmium (Ni-CD) or Nickel Metal Hydride (Ni-MH) batteries or lithium-ion batteries (Li-ion) batteries.
Ni-CD Batteries
The NI-Cd batteries are made up of Nickel Hydroxide, and Cadmium. Nickel-cadmium cells have a nominal cell voltage of 1.2 Volt. The NiCd batteries suffer from a "memory effect". Due to memory effect the batteries once discharged and recharged to the same state of charge number of times remember the point in its charge cycle where recharging began. During subsequent use the battery suffers a sudden drop in voltage at that point, as if the battery had been discharged. Thus to get full efficiency from NiCd batteries they should be fully discharged before recharging them again.
Th NiCd batteries have smaller shelf life. The NiCd batteries are cheaper than Ni-MH and Li-ion batteries.
Ni-MH Batteries
The NiMH battery uses a is nickel oxyhydroxide (NiOOH as positive electrode and hydrogen-absorbing alloy for the negative electrode . A NiMH battery has two to three times the capacity of a same size NiCd battery. The NiMH do not suffer from memory effect but are costlier than NiCd batteries.
Li-ion Batteries
The cathode of a lithium-ion battery is made of lightweight lithium and anode using porous carbon. The Li-ion batteries have higher energy density than Ni-Cd and Ni-MH batteries. This allows them to store more energy for the same size.
The Li-ion batteries also operate at higher voltages 3.7 volts of than 1.2 volts for NiMH or NiCd. Thus a single cell can be used rather than multiple NiMH or NiCd cells. Li-ion batteries have lower self discharge rate than Ni-Cd and Ni-MH batteries. Thus they can retain their charge for longer period than Ni-Cd and Ni-MH batteries
The Li-ion batteries have complex manufacturing process and are more expensive than NiMH or NiCd batteries. They also need special charging circuit to avoid damage due to due to overcharging or undercharging.
Increasing Battery Life
The life of cordless phones battery can be enhanced with given proper care and maintenance and can be recharged many times.
i. The batteries should be charged fully before first-time use. This prolongs battery life and ensures good performance.
ii. Cordless phone batteries take longer to charge due to charging methodology. It’s best to leave charging for 24 hours or as recommended by phone supplier.
iii. The batteries life can be extended by discharging them fully and then recharging them fully every two to three weeks.
iv. The batteries should not be stored in freezer or hot environment.
v. The batteries should never be left long in uncharged condition.
Points To Look For While Buying Batteries
Date of Manufacture Or Use
The dates of manufacture or use before date are printed on batteries package. The batteries whose date of use is over should not be bought. The batteries which are manufactured more than a year before manufacturing also should be avoided.
Type Of Battery
Use batteries of the type recommended by the manufacturer. As the charger for the cordless phone batteries is built into the base the change in type of battery may not utilize full potential of the battery.
Battery Rating
The battery, apart form the type, is rated for its voltage and capacity (given in milli ampere hour (mAh)). The higher the rating, the longer is the use life of battery. The battery of recommended rating only should be used.
