A microcontroller-based intelligent fast-charger for Ni-Cd and Ni-MH batteries in portable applications

In portable applications, Ni-Cd and Ni-MH batteries are the most frequently used. In this paper, a new fast-charger is presented for these kinds of batteries, which is able to perform a full-protected charge mode. The control and supervision of the whole process is entrusted to the microcontroller, which that must be able to find out the initial battery state (detecting deteriorated devices), decide the fit way to charge the battery (in order to ensure a long cycle-life) and determine when the charge process must be finished. In this way, the state of the battery is perfectly controlled all of the time, in order to avoid any damage; including those related to an incorrect user´s operations. The use of a microcontroller has been considered in order to simplify the hardware required (only a few external components are used), and provide a powerful and intelligent tool to undertake, through the programmed algorithm, complex tasks. This paper presents the implementation of this optimized fast-charger and the experimental results obtained