A battery charger, recharger, or simply charger, is a device that in an by running through it. The charging protocol—how much and current, for how long and what to do when charging is complete—depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging after the battery has been f.
How does a battery charge work?
The constant voltage is applied till the current taken by the cell drop to zero, this maximizes the performance of the battery. Charge Termination:- The end of charging is detected by an algorithm that detects the current range that drops to 0.02C to 0.07C or uses a timer method.
The complexity (and cost) of the charging system is primarily dependent on the type of battery and the recharge time. This chapter will present charging methods, end-of-charge-detection techniques, and charger circuits for use with Nickel-Cadmium (Ni-Cd), Nickel Metal-Hydride (Ni-MH), and Lithium-Ion (Li-Ion) batteries.
How long does a battery take to charge?
About 65% of the total charge is delivered to the battery during the current limit phase of charging. Assuming a 1c charging current, it follows that this portion of the charge cycle will take a maximum time of about 40 minutes. The constant voltage portion of the charge cycle begins when the battery voltage sensed by the charger reaches 4.20V.
An intelligent charger may monitor the battery's voltage, temperature or charge time to determine the optimum charge current or terminate charging. For Ni–Cd and Ni–MH batteries, the voltage of the battery increases slowly during the charging process, until the battery is fully charged.
How do Inductive battery chargers work?
Inductive battery chargers use electromagnetic induction to charge batteries. A charging station sends electromagnetic energy through inductive coupling to an electrical device, which stores the energy in the batteries. This is achieved without the need for metal contacts between the charger and the battery.
How does a battery charge cycle work?
The constant voltage portion of the charge cycle begins when the battery voltage sensed by the charger reaches 4.20V. At this point, the charger reduces the charging current as required to hold the sensed voltage constant at 4.2V, resulting in a current waveform that is shaped like an exponential decay.