What You Need to Know About the 14500 Lithium Battery

In recent years the 14500 Lithium-ion battery has proudly found its place among its AA battery next to a 14500 lithium batterylithium cousins. As pictured here, (for comparison) a 14500 lithium cell is identical in shape and size to a standard AA battery. But that is where the similarities end.

Similar, Yet Different

  • All standard alkaline batteries are 1.5 volts. Most lithium batteries (incl. the 14500 lithium battery) are 3.7 volts. That’s a major difference!
  • Standard 1.5 volt batteries are disposable. The 3.7 volt 14500 lithium cell is rechargeable.
  • For most devices, a 14500 battery provides at least double the sustainable power as an alkaline cell, and being rechargeable, they’re just better all around. 

Check Your Voltage!!

voltsWhat is absolutely essential, is that the device that is intended to be powered by a 14500 cell, be able to accept a 3.7 volt battery!! Again, the list of devices that are made for 1.5 volt batteries, but are also able to utilize a battery of this voltage are VERY limited.

 LED Flashlights

Many, if not most flashlights that run on ONE AA cell, can also accept a 14500 lithium battery. MOST flashlights that use TWO AA cells, CANNOT accept 14500 batteries. This edc lightsis because the voltage of the light will typically not go above 4 volts. Ergo, ONE 3.7 volt battery is okay, but TWO of them, is TOO MUCH voltage! It would physically kill your flashlight to feed it that much power! 

For a 2xAA flashlight to be able to run on two 14500’s, the light would need to be able to accept up to 8 volts. I don’t know of any that do. The only reason for using a 14500 in a flashlight is to get a boost of lumens. Most should be brighter, but it depends on the light. It’s also a good idea to read the manufacturers specifications carefully, which should indicate the working voltage range. Sometimes even though the light might accept the cell, the manufacturer might void the warranty if the cell causes the unit to fail. This is dependent upon whether the manufacturer stands behind the use of lithium cells. If they advise against it, it’s their right to void the warranty.

Heat Advisory

Sometimes, using a 14500 battery in a flashlight can cause it to become unusually hot. Caution is advised in that case, even though many flashlights have protective measures at dealing with LED generated heat. Try to make sure the device you’re powering can handle voltages over 1.5, or the extra power could cause irreversible damage. When using Lithium-ion batteries it’s very important to know how to handle them, and to be aware of the possible dangers… such as added heat. This post talks about handling lithium cells safely.

14500 lithium batteries can do great things… just make sure your device can handle the extra boost of power!

For purchasing options of 14500 batteries on Amazon; click here!


Was this article helpful?
Sign up and receive free updates straight to your inbox. I will never share or sell your email address with anyone.
I agree to have my personal information transfered to MailChimp ( more information )
Please follow Lightsngear and like us:


  1. dummy AA cells (with a wire conductor + and – internally) can be had to allow 14500 to be used in devices that accept 2xAA

    • Yes… I don’t have any AA spacers, but thanks for the info.

    • fully charged 14500 of 4.2 volts are still much higher than 2xAAs of max 3 volts. you’re just lucky that your device accepts the extra 1.2 volts.

      • Thanks for commenting!

        Yes 14500 batteries are excellent alternatives when looking for an extra boost in power. There are many flashlights that can accept them.

      • Fully charged Li-ion batteries can be as high as 4.35v, depending on the charger. Programable chargers can charge to an specified lower voltage, which is good for the longevity of the batteries. Milspec is to charge them to 4.00v, which gives many more cicles for a modest reduction in capacity. The recommended cutoff voltage is 3.00v, in any case. It is safe to discharge to 2.75v with the same caveat of a higher charge voltage.
        Brand new Alkaline batteries can be as high as 1.85v each, or 2×1.85v=3.70v, 3×1.85v=5.55, and can and should be discharged to 0.9v, or 1.8v combined for two and 2.7 for three.
        So it is safest and most compatible to use one Li-ion to replace three Alkalines.

  2. I have an LED flashlight that has a ring at the positive end. It allows some + tip batteries to reach the contact but others do not. WHY are 14500 batteries with “different overall lengths” and “different + tip lengths”. I had to buy 3 times to buy one that would make contact with both ends. Yes all three work if I added an extension of the + tip but one shouldn’t have to. Why is this? Since all are the same 3.7V.

    • It’s an interesting question Mike, and it doesn’t ONLY affect 14500’s. 18650 batteries can also vary in length, and sometimes in thickness as well. With regards to length, it usually varies because of the protection circuit that’s added to it. I’ve experienced this too, and have a few 14500’s that won’t work it certain lights. That CAN be one particular problem when buying single AA/14500 lights. There’s always a chance that some brands of batteries will be too long. The solution is to power them with unprotected 14500’s, which USUALLY fit more easily. Olight (for example) makes great batteries, but their protected 14500’s are typically longer than most.

      So, the unfortunate answer to your question, is simply “because they can be”.

  3. Can a 14500 1200mAh 3.7V Li-ion battery be used in a Xbox one controller?

    • First of all, there’s no such thing as a 1200mAh 14500. The MAXIMUM capacity is 750mAh. If you HAVE one (or have seen them for sale online) that claims 1200…I’m afraid it’s not the ‘real McCoy’. So. I don’t own an Xbox, but from what I’ve seen, they use two AA’s. Is that the case with yours? And if that’s true…then NO they will NOT accept 14500’s because the voltage will be WAY too high! If you’d like to use rechargeable batteries in it, then you’ll need to get 1.2 volt NiMH Eneloop cells. You can get them off Amazon, and they even have them under their “Basic” label as well.

      Thanks for the question Chad!

  4. One thing to keep in mind is the loss of voltage when in cold temperatures. Have a “KLARUS 750mAh 14500” which went from full charge to below safe operating voltage when below freezing during the night. so always carry some regular “ALKALINE” batteries for my Headlamp.

Leave a Reply

Your email address will not be published. Required fields are marked *