This circuit uses a microcontroller and simple algorithm managing voltage regulator ics and discrete components to control charging of nickel cadmium batteries.
Simple nickel cadmium battery diagram.
Circuit diagram circuit operation.
Nickel cadmium batteries generally require a constant current charging.
Figure 1 shows a schematic diagram of a simple circuit that can be used to dissolve the whisker formation that prevents nickel cadmium batteries from receiving a charge the circuit consist of nothing more that two fully charged series connected nicad batteries b1 and b2 and a switch s1.
The below shown nicad charger circuit is developed to supply either 50ma to four 1 25v cells type aa or 250ma to four 1 25v cells type c connected in series eventhough it could simply be modified for various other charging values.
Hence it is widely used in hand held and compact electronic devices.
Nicd batteries provides better performance in compact size.
This circuit can also recharge common dry cell battery for fewer times at certain level.
Nickel cadmium batteries at the 1 2h rate yield twice the energy density of lead acid batteries i e.
Previously we have built many types of charger circuits that incudes solar mobile charger float charger circuit 12v battery charger power bank circuit etc.
This circuit has a built in automatic current regulator.
Today we are going to build charger circuit for charging ni cd battery the process of charging nickel cadmium batteries can be done in two ways.
In the united states part of the battery price is a fee for its proper disposal at the end of its service lifetime.
So nickel cadmium batteries come in multiple of 1 2 v for eg 2 4v 3 6v 4 8v etc but it maintains constant voltage throughout their service life and about 0 8 1 v when discharged.
Nickel cadmium cells have potential of 1 2 v.
It provides a steady charging.
Nickel cadmium batteries are used in various developmental electric vehicles.
They operate over a wide temperature range give approximately 2000 cycles and can be charged in less than 1 h.
When fully charged the positive plate is ni oh 2 and negative plate is cd oh 2 while discharging the positive plate converts into ni oh 3 and the negative plate is converted into pure cd.
The chemical reaction in the nickle cadmium battery or cell is perfectly reversible.
Simple nicd battery charger circuit made with few easily available.
The chemical conversion is reverted when a discharged battery is charged again.
Ni cd batteries contain between 6 for industrial batteries and 18 for commercial batteries cadmium which is a toxic heavy metal and therefore requires special care during battery disposal.