# Quick Answer: Do I Need A Resistor For Each LED?

## How do I know what resistor to use with LED?

To calculate the resistor needed for a simple LED circuit, simply take the voltage drop away from the source voltage then apply Ohm’s Law.

In other words….

## Can I connect a LED directly to a battery?

Powering an LED is not as easy as simply hooking it up to a battery. An LED has almost no internal resistance. Therefore, if you hook it up directly to a battery, it will burn out quickly as the current flows unimpeded through the LED. You must add a resistor to the LED circuit.

## How many LEDs can a 12v battery power?

The answer should be the source voltage divided by the voltage drop of 1 LED. So if your source is 12v, and your LEDs have a voltage drop of 3.5, 12/3.5v, gives you 3 LEDs. If the the forward voltage drop of the LEDs was exactly 3 volts, you’d be able to drive 4 of them, and would not need a current limiting resistor.

## Can I connect 12v led to car battery?

Answering your question: you can’t use a 12v battery to power a 12v led strip directly. a fully charged lead acid will have 13.8v which will burn out your led strip if you are doing so. You don’t need a current limited device.

## Is 9v too much for an LED?

A 9V battery can’t supply very much current, but without series resistor the current may still be too much for the LEDs. … In theory you could do without resistor, but the LEDs are never exactly 4.5V and your battery is never exactly 9V.

## What happens if you don’t use a resistor with an LED?

If you don’t put a resistor in series with the LED and you apply power, the current through the LED will exceed its rating and it will be destroyed. You can use the following equation to solve for R. Vdiode is the diode’s forward turn on voltage.

## How many resistors do I need for LEDs?

We’ll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms. To use several LEDs in parallel, sum the current values.

## How many LEDs can be connected in parallel?

Wiring LEDs in parallel allows many LEDs to share just one low voltage power supply. We could take those same four 3V LEDs and wire them in parallel to a smaller power supply, say two AA batteries putting out a total of 3V and each of the LEDs would get the 3V they need.

## Can I connect led without resistor?

Never Ever Connect an LED Without a Resistor, Mostly. When hooking up an LED, you are always supposed to use a current-limiting resistor to protect the LED from the full voltage.

## Do I need a resistor for a 12v LED?

Originally Answered: In order to light an LED with a 12V, what resistor value is needed? Normally, you want to minimize waste, so you connect as many LED in series as possible to consume the voltage provided, then you use a resistor to limit the current to the correct value. White LEDs are universally using 3.0 volts.

## What is the maximum voltage a LED can withstand?

about 3.0 voltsThe maximum voltage applied it a single white LED is about 3.0 volts. Several LEDs in series can match a higher voltage supply, or a resistor (or other current limiting circuit) can be used to limit the current.