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How Long Do LED Lights Last On Batteries

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LED lights powered by batteries are versatile and economical. Whichever type you have, it is meant to serve you for a long while. This begs the question, how long do LED Lights last on batteries? We went through the statistics and research to figure out this important fact for you.

How Long Do LED Lights Last On Batteries?

Standard LED battery light sets should ideally last about 18-24 hours on a set of fresh 3 AA batteries. The lesser insulated Micro drop LED light sets should go for more than 100 hours with 2 round C-batteries or a new set of 3 AA batteries.

When buying either the LED lights or the batteries used, you won’t be given the exact time the batteries will last. This is because the lifespan of the batteries depends on how long or how frequently you use them. Additionally, the type of LED light and batteries used will inform how long they last. 

Woman wondering how long do LED lights last on batteries

How Can You Calculate The Time?

To get to the figures we have mentioned above, you can apply a simple, mathematical formula to show how long a battery can last. The electrical power formula states that Watts = Amps × Volts.

For example, consider your batteries have a capacity of 6500 milliamp-hours (mAh) or 6.5 amp-hours (Ah). On the other hand, your LED light set runs on 12 Volts. Using the formula, this translates to 78 Watt-Hours, which is the battery capacity in time

If the total wattage of your LED lights is 20 Watts, divide that battery capacity by this figure. You will find that our batteries can sustain the light set for 2.9 hours (78 / 20). Therefore, you expect your LED lights to go off after almost 3 hours.

The type of batteries you get can make or break the deal. This is why we recommend you get quality ones from high traffic stores that have numerous battery turnover. Before settling for a brand though, you should know which batteries can run your lights.

Types of Batteries Used in LED Light Sets

There are several battery types used to fire up LED lights. For instance, we expect the batteries you use for LED work lights to be different compared to flashlights. In general, there are three common types of batteries used with LED lights: 

Alkaline Batteries

These are the types of AA, AAA, and C with an advanced shelf life of 5-7 years. They follow the reaction that takes place between zinc and manganese dioxide. Compared to zinc-carbon batteries, these have higher energy density.

These batteries are popular because they are affordable compared to others with better energy densities like the silver oxide ones. While most are one time, there are rechargeable alkaline batteries too.

You can use these for high draining devices like a LED lantern, moderate drain devices like digital cameras, and low drain devices like LED flashlights. Ultimately, how much and often you use them determines their real life span.

Lithium-ion Batteries

These are rechargeable with a voltage of 3.6 and many people refer to these as Li-ion batteries. You can recharge them for approximately 500-1000 cycles. Many people divide them into subcategories based on chemistry, price, performance, and safety features.

Although Li-ion batteries depend on Lithium ions to function, they are different from Lithium primary batteries which are disposable. When they are working, the lithium ions, from the negative electrode in the cell are attracted to the positive electrode.

LED flashlight

As you recharge them, the reverse reaction occurs until they are full. When it comes to uses, most people use them in consumer electronic products like rechargeable LED headlamps, among other applications.

This is mainly due to their high energy density, lack of memory effort, and a relatively slow loss of charge. Though a bit costly, manufactures are looking for ways to make them more affordable without compromising their quality.

NiMH Batteries

Nickel Metal Hydride batteries have a voltage of 1.2 and are rechargeable, with an estimated 100-500 charging cycles. They offer the same energy density as the Lithium-ion batteries. Moreover, they can hold up to triple the charge compared to nickel-cadmium batteries.

In these batteries, the positive electrodes consist of nickel hydroxide. The negative electrode, which is capable of absorbing hydrogen, is an alloy. Compared to the standard 1.5V cells, NiMH is a little lower.

Thanks to their compact dimensions and small size, many people use them to replace Nickel Cadmium batteries. That’s also why many people use AA batteries of the range 1100mAh to 3100mAh.

If you are looking for high-density cells with a small size, these are the ones you need. Luckily, they come at very economical prices.

Why You Need To Use Resistors

Most LEDs in the market are 5V. Ideally, you can connect them to a power source of the same voltage drop without any damage. However, if you plan to connect them to a power supply of above 5v, you need an external resistor.

Though they usually have an inbuilt resistor that regulates voltage, it is inadequate at higher voltages. External resistors have different values. You need to get one that fits your series. To determine the right one, you need to figure out the required resistor value.

To achieve this, we use Ohm’s law, which dictates: voltage = current × resistance. Take a case where a LED light set needs 5V and our batteries are 9V. We will need a resistor that will be able to drop that voltage by 4V.

If you have a current of 20 milliamps, you substitute the values in the formula to find the resistance. R = 4 / 0.02 = 200 ohms. Therefore, you will need a 200-ohm resistor for your LED series.

After understanding how batteries and resistors work, you should try out connecting a LED light series. If you have no idea how to, worry not. Here is how you can achieve that:

How to Connect LED lights to a 12V Battery

The reason a lot of people love LED lights for their households is that they are cost-effective. Why not go the whole way and save more bucks by fixing it yourself? You will need:

LED bulb lights
  • 12V Battery
  • LED lights
  • Electric Wire
  • Resistor
  • Voltmeter
  • Diode test function meter
  • Wire strippers or utility knife

Like any other project, you need to do a little planning ahead. Decide forehand where you want the lights to be. Most batteries for LED lights don’t need the same support as those going high up in the chandelier.

As expected, this will determine where you need to place your box or other preferred support systems. Besides, it will dictate how long your electric wire will be. The length should be enough to connect the LED light set to where your on/off switch will be.

Once that is settled, check if your batteries and switches are working. You can wire both items to a working device, like a lamp. If you have a voltmeter, check the current. With that done, everything is set for installation:

  1. Assemble your LED lights where you want them to be and find the leads. The lead attached to a larger node is the positive one, the negative lead is the shorter one or the one with a flattened section on a round LED.
  2. Do the diode test to confirm you have identified them correctly. If the diode test function meter lights up, the red test lead will be attached to the anode and the black test lead to the cathode.
  3. Using your wire stripper or utility knife, cut two pieces of the electric wire according to your desired length. Strip off an inch of insulation on all ends for soldering.
  4. Connect each wire onto the ends of the resistor. It can limit the current through the circuit from either side.
  5. Connect one end of the resistor to the cathode and the other to the anode.
  6. Solder the electric wires to your batteries.
  7. Ensure the positive lead (anode) connects to the on/off switch, which in turn connects to the positive port of the battery.
  8. The negative lead (cathode) should connect directly to the negative port of the battery.
  9. Switch them on and check if the LED lights are working.

Reasons Why Your LED Lights Might Not Illuminate

If you connect your lights and they do not work, there are many reasons why this could happen. The best part is that you can easily rectify most of these problems. 

Loose Connection

You might have soldered your electric wires loosely at a point between the LED lights and the battery. As a result, no current is passing through. To correct this, check where the hitch possibly is or connect the series afresh.

Damaged LED

In most cases, when a LED is damaged, the driver is the problem. The chips responsible for illuminating light might be perfectly fine. That being so, you need to get a new driver as opposed to the whole LED. If you have a warranty, you’ll get another one for free.


Did you enjoy reading this informative article? We believe now you can correctly tell how long LED lights last on batteries. If you want to try out LED lights on batteries for your house, what we have discussed will take you a long way in achieving a successful light series.