Do not charge batteries directly from the power supply. The charging current must be limited. Depending on the type of power supply, this can be done in one of two ways.
Instructions
Step 1
Check the battery type. It must be either nickel cadmium (designated NiCd or NiCad) or nickel metal hydride (designated NiHM). Never charge lithium-ion, lithium-polymer, lithium-iron or other lithium-containing batteries with any charger other than those supplied by the manufacturer. Do not charge electrochemical cells, especially those using metallic lithium.
Step 2
The simplest case occurs when your existing power supply has a current stabilization mode. Such a block has two regulators: voltage and current. It operates in the mode of stabilization of the set voltage set by the first regulator until the consumed current exceeds the set by the second. Then it switches to the current stabilization mode, from which it exits after the load current falls below the set value. In this case, simply set the voltage one volt higher than the nominal for the battery, and the current equal to the charging current. Then connect the battery to the unit, observing the polarity (i.e., connecting the same poles of the unit and the battery), then turn on the unit.
Step 3
Most often, however, there are power supplies that can only stabilize voltage. If you have just such a device, turn on the current stabilizer in series with the battery. The simplest such stabilizer is an ordinary incandescent light bulb. The voltage for which it is designed should be equal to the difference between the output voltage of the power supply and the voltage on a completely discharged battery. The same for which the light bulb should be designed, choose close to the charge current. When connecting the battery in this way, also observe the polarity. Be sure to measure the current in the circuit, and if it is not equal to the calculated one, use a different bulb.
Step 4
Calculate the battery charge current itself using the following formula: I = c / 10, where I is the charge current, A, c is the battery capacity, Ah
Step 5
Choose the charging time equal to fifteen hours. Do not short-circuit a charged or discharged battery under any circumstances.
