EOTech with batteries

How Long Do EOTech Batteries Last?

Batteries are critical on nearly all pieces of electronic equipment, but on a weapon sight, the longevity makes the issue especially important. The batteries dying at a critical time could be a fatal error.

EOTech’s are chosen by some of the finest instinctive shooters out there, so how long do the batteries last in an EoTech?

EOTech gives the batteries a longevity between 600 and 2000 hours in their products. This depends on battery type, style, usage, and number. In practical terms, it’s recommended to swap out the EOTech batteries every 3 to 4 months.

Battery life is subject to consumption and brightness settings from the user. 

Some of them give you an option to switch off after 4 hours automatically which stops battery depletion, as well as having a motion assist which leaves the battery on permanent standby until the movement is detected.

Let’s find out more about EOTech batteries and some of the ways you can extend their battery life.

eotech fake sight look up

Comparing The EOTech Models With Battery Life

There are two main types of batteries for EOTech systems – AA batteries and CR123 batteries.

The AA batteries have been in use for longer, and they are often heavier, easy to find, and cheaper. The CR123 batteries were introduced a few years back, and they’re more powerful and expensive. 

They also make it possible to achieve a lighter red dot sight. 

Below are some of the most popular EOTech sights, their battery types, and estimated battery life.

Model Battery Type Battery Life
XPS2 CR123 1000 hours
XPS3 CR123 1000 hours
512 2 x 1.5 V AA batteries 2200 – 2500 hours
EXPS3 CR123 1000 hours
558 1.5 AA batteries (It also supports CR123) 2500 hours
518 2 x 1.5 V AA batteries (It also supports CR123) 2200 – 2500 hours
552 2 x 1.5 V AA batteries 2200 – 2500 hours
556 2x 3.0V Lithium 123 batteries 1,100 continuous hours at nominal setting 12
EXPS3-4 A single 123 lithium battery 600 continuous hours at nominal setting 12

If the EOTech battery has a 1000 hours battery life and switches off after every four hours, you can use it 250 times. 

This translates to approximately 3 years, rather than the five years depicted by the manufacturers. 

However, the battery also drains when in the sights, even when you’re not using it. It would be best to not let the battery last more than six months in the sights.

EOTech Battery Life Without Use

When the sight is off, the battery will still lose some voltage. That’s just what happens with electronic equipment.

How long a battery lasts will largely depend upon this draw.

The laser unit is the only thing that turns off when not in use. 

Otherwise, since the microswitch requires power at all times, the capacitors and microprocessors do not turn off. 

The manufacturer advises the users to remove the battery if they do not use the red dot sight in a long time. How many people do that is anyone’s guess.

Luckily though, EOTech systems will not lose its zero since it’s mechanical.

eotech battery compartment

Extending EOTech Battery Life

The EOTech holographic sight has more to offer compared to iron sights. That is why it would be disappointing if the EOTech batteries run out unexpectedly. Luckily, there are ways of prolonging the battery life of your EOTech. These include;

  1. Swap the batteries: Make a habit of swapping the existing batteries with new ones. Preferably after three to four months of use. Have a bunch of batteries in stock to allow frequent swapping.
  2. Change to lithium batteries: That is if your model supports the CR123 batteries. On average, lithium batteries can last for 3-5 years. Why? Unlike alkaline batteries that have a steep voltage drop, lithium batteries have a steady voltage curve. This constant voltage curve runs throughout the whole battery life. With the desired long-lasting effects, the CR123 lithium batteries don’t come easy and cheap. But, why save a few coins buying the alkaline version and spend more on replacing them often?
  3. Take out the batteries: If you are not using the EOTech, remove the batteries. As mentioned earlier, the sights aren’t really “off.” The capacitors are still running as long as the battery is in there.
  4. Use the switch off option: Some of the sights have the option to switch off after every four hours. So take advantage of this setting in case you forgot to turn the sight off.
  5. Use lower intensities: EOTech systems use a more powerful laser that takes a toll on the batteries. Some of the sights have up to 30 intensity levels. So to conserve the battery life, you can keep the intensity at level 12 or lower.

Final Thoughts

Different models of EOTech red dot sights will use different batteries, perhaps even doubling up with them. Even on the lowest battery life, that’s 600 hours of usage.

In theory.

It really all depends upon how often you use the sight, and whether you have long periods of non-use. Don’t expect the batteries to last forever in there.

Some models run better on the alkaline battery version like the classic 522, while others like the XPS series operate safer and longer on the CR123 lithium batteries. Some will also run with both batteries.

Therefore, make sure before you purchase, you understand the model and the recommended batteries for use. Nonetheless, lithium batteries take the crown when it comes to durability. 

Whichever battery you’re using, remember to replace them every three to four months to prolong their lives and maintain a consistent supply of power.

After all, you do want the sight to work when it matters most.

Even with all the battery life issues, nothing beats the EOTech brand when it comes to holographic sights. The performance of its models is commendable and endorsed by the Navy Seals.


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