i've found my father's power supply for his handphone.then i take the power supply and use it to charge my r/c batt.the problem is the battery get hot in a minute and the batt is not fully charge at all.the power supply rating 13.38v max7A(what it mean by max7A) and my batt is 7.2v 1200maH.
i've found my father's power supply for his handphone.then i take the power supply and use it to charge my r/c batt.the problem is the battery get hot in a minute and the batt is not fully charge at all.the power supply rating 13.38v max7A(what it mean by max7A) and my batt is 7.2v 1200maH.
Yes, that's the basic difference between a power supply and a charger. You simply calculate the resistor value using ohms law.
The current is the charging current you require, and the voltage is the difference between the supply and battery voltages. You will need a suitable large wattage (wirewound) resistor.