How to make a power supply charger
Charge the batteries directly from the power supply can not be. It is necessary to ensure limitation of the charging current. Depending on the type of power supply, it can be done in one of two ways.
Instruction of how to make the power supply charger
Check the type of battery. It should be either nickel-cadmium (NiCd or designated as NiCad), or nickel metal hydride (denoted NiHM). Never charge lithium-ion, lithium-polymer and lithium-iron-containing compounds and other lithium batteries with any chargers other than the factory. Electrochemical cells, especially those in which metal lithium is used, no charge at all.
The simplest case occurs when your existing power supply has a constant current mode. This unit has two regulators: voltage and current. It operates in the stabilizing mode, a predetermined voltage specified by the first control, as long as the input current exceeds a predetermined second. He then switches to the constant current mode, from which emerges after the load current falls below the predetermined value. In this case, just set the voltage to one volt greater than the nominal battery, and the current - a current equal to the charge. Then, connect the battery to the unit, the polarity (ie, connecting like poles and the battery unit), then turn on the unit.
Most often, however, there are power units, capable of stabilizing the voltage only. If at your disposal there is a device in series with the battery switch on the current stabilizer. The simplest such stabilizer is a conventional incandescent bulb. The voltage at which it is calculated shall be equal to the difference between the output voltage and the voltage on a fully discharged battery. The same, which should be designed lamp, select the closest to the charge current. When the battery is connected in such a way as to observe the polarity. Be sure to measure the current in the circuit, and if it is not equal to the calculated, use a different bulb.
Battery current itself calculate the following formula: I = c / 10, where I - the charge current, A, c - the battery capacity Ah
Charging select equal to fifteen hours. Neither charged nor discharged battery under any circumstances short-circuit.