How To Reduce Battery Voltage? – 9 Steps

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Electrical components have specific ratings such as ampere rating and voltage rating; these ratings must be considered when connecting the component to an electrical circuit. If the rating was exceeded, this could endanger the component safety; however, the voltage rating is different from the current rating. Therefore, it can’t be skipped; the voltage must be reduced. 

How To Reduce the Voltage of a Battery?

To reduce the voltage of a battery, you will need to build a voltage divider circuit. To build a voltage divider circuit, you need to follow these steps:

  1.  Step One
    Grab a multimeter, adjust the multimeter to resistance mode “Ohms,” and then use the multimeter to measure the resistance of the circuit. The resistance should be measured to know what other components you need to build the voltage divider circuit.
  2. Step Two
    Choose a random resistor; the resistance value of the resistor doesn’t matter because it’s not always the resistor that you will end up using in the circuit. Instead, you are using the random resistor to determine the ratios of the resistances required to reach the voltage value you want.
  3. Step Three
    Add the value of the resistance of the circuit you measured with the multimeter to the resistance of the random resistor. Then, multiply the circuit’s resistance value by the resistance value of the random resistance; after that, divide the product by the sum.
  4. Step Four
    The value resulting from the division of the product by the sum is the effective resistance, which is the actual resistance of the circuit when these two resistors are connected. Next, divide the battery voltage by the voltage you want to have; the result is the multiplication factor that your second resistor needs to form the voltage divider.
  5. Step Five
    Multiply the multiplication factor by the effective resistance to get the resistance value you need to reach the required value. Now, you need to find a resistor with the value that resulted from the multiplication step; if you can’t find a resistor with the same value, you can repeat the process to get a new lower value.
  6. Step Six
    The two resistors have to be connected one after the other, so you need to bend their leads straight down and then connect them to the circuit that needs reduced voltage. The arrangement doesn’t matter when connecting resistors because they have no polarity, so you can connect them in any way.
  7. Step Seven
    Use the soldering iron tip to solder the two resistors on the board by touching the tip to the lead of the resistor, where it connects with the board. Connect one lead to the board for each resistor, then connect the other lead of the first resistor to the second one.
  8. Step Eight
    Prepare several wires of short length by removing one inch of their insulation; you remove the insulation from any end you prefer. Next, choose any wires and solder one of them to the battery’s positive terminal, and solder the other wire to the battery’s negative terminal. Solder the first wire’s free side to the first resistor free lead, and solder the second wire’s free side to the second resistor free lead
  9. Step Nine
    Solder two wires from the wires you have prepared to the smaller resistor; these two wires will be used to provide the low voltage to the component you want to connect

Why Reduce the Voltage of a Battery?

Because the voltage of some batteries could be larger than what the connected components require, the voltage must be lowered to protect the components. The voltage is the pressure that pushes the electrical particles to move through; this movement is known as the electrical current. 

You can imagine the voltage as the pressure of a river on a rock; meanwhile, the current is the water in the river. The rock can tolerate a certain amount of water pushed against it, but when the pressure increases, the amount of water pushed will increase and exceed what the rock can tolerate.

Therefore, sooner or later, the rock will be affected due to the excess amount it’s facing; it’s the same thing when it comes to voltage and electrical components. In normal conditions, the devices only draw the amount of current they need, so it’s fine if the produced current is more than what it needs.

However, when the voltage is above what is required for the device, it forces the device to draw more current than what it needs; this could damage the device.

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How Does a Resistor Affect the Voltage of a Battery? 

The resistor, when connected to a circuit that is supplied by a battery, the voltage across it can be determined by multiplying the current passing through the resistor and the resistance of the resistor. For example, if the current passing through the resistor is 1.2 Amperes, and the resistance of the resistor is 10 ohms. Therefore, the voltage across the resistor is 1.2 * 10 = 12 volts.

When you connect another resistor, the voltage across the first resistor will change; for example, if you connect another resistor of 5 ohms. The circuit’s total resistance is 10 + 5 = 15 ohms; therefore, the current will decrease as the resistance has increased, and the current will be 0.8 amperes. 

The voltage across the first resistor will be 0.8 * 10 = 8 volts; meanwhile, the voltage across the second resistor will be 0.8 * 5 = 4 volts. This means the battery’s voltage will be the same 8 + 4 = 12 volts; meanwhile, the voltage across the first will decrease from 12 volts to 8 volts. 

How Does a Resistor Affect the Current of a Battery? 

The current generated by the battery is affected by resistors due to their resistance; the resistance is a physical obstacle that the current faces when passing through a resistor. When the resistance increases, the current decreases; for example:

If the current is 1.2 amperes when the resistance is 10 ohms, the current will decrease to 0.8 amperes when the resistance increases to 15 ohms. The current lost when passing through a big resistance is transferred into heat, and the electrical chargers start to collide with each other, and they lose their energy in the form of heat. 

Conclusion

To sum up, to reduce the voltage of a battery, you will need to build a voltage divider circuit. To build a voltage divider circuit, you need to follow these steps:

  1. Grab a multimeter, adjust the multimeter to resistance mode “Ohms,” and then use the multimeter to measure the resistance of the circuit.
  2. Choose a random resistor; the resistance value of the resistor doesn’t matter because it’s not always the resistor that you will end up using in the circuit.
  3. Calculate the effective resistance of the circuit.
  4. Next, divide the battery voltage by the voltage you want to have; the result is the multiplication factor that your second resistor needs to form the voltage divider.
  5. Multiply the multiplication factor by the effective resistance to get the resistance value you need to reach the required value.
  6. Find a resistor with the same required value, or repeat the steps to find a more suitable value if you can’t find a resistor with the same required value. 
  7. The two resistors have to be connected one after the other, so you need to bend their leads straight down and then connect them to the circuit that needs reduced voltage.
  8. Use the soldering iron to install the two resistors to the board by fixing one end from each resistor to the board.
  9. Connect the two resistors to the battery, and then connect the small resistor to two wires used to connect the component that needs lower voltage. 

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