Ever wondered how many options are available for powering your headlamp or flashlight? As technology advances, a once simple choice becomes difficult but rewarding, and suited precisely for your needs. Nowadays you can go with the oldies but goodies AA or AAA batteries which are widely available or with the newer giant, the 18650, which can be charged many times and possibly be the right fit for not just your headlamp or flashlight, but other devices. We have compiled a bunch of information regarding all you need to know to make the right choice when it comes to powering your lighting devices.
Headlamps and flashlights use a variety of batteries. Your choices are AA, AAA (Alkaline or Nickel Metal Hydride), Coin Batteries (CR2032), 18650, and Li-Ion (Lithium-Ion). We have created a list for you to refer to. Your choices are, again, as follows:
| Type / Size | Rechargeable | Non-Rechargeable |
| Alkaline AA | √ | |
| Alkaline AAA | √ | |
| NiMH AA | √ | |
| NiMH AAA | √ | |
| Coin Battery (CR2032) | √ | |
| 18650 | √ | |
| Li-Ion | √ |
Lifetime Of Batteries
AA/AAA
The lifetime of all of these varies so much that once you have chosen a type you should conduct research on your own. We have found a video on YouTube that makes it easy for AA/AAA. These are some of the best solution for someone who does not want to purchase new chargers or do lots of research and they are the tried and true batteries we all know of. We have personal experience with the Duracell line and highly recommend the 2450 line as they have held their charge consistently over the last year of ownership.
Coin Batteries
Coin batteries are rarely seen in a headlamp, but they are definitely out there and can make for amazing backup devices or even running headlamps as the enclosures are typically small and lightweight. The typical battery life for coin batteries in a headlamp with 15 lumens will be about 10 hours. These batteries can also be found in the rechargeable form, but I have not come across a reliable brand or set that I can recommend. One of the best headlamps I have come across that use this battery is the Petzl e+LITE.
18650
The battery life of an 18650 cell will range from 45 minutes – 200 hours depending on the settings you use. If we assume you are using a headlamp with a maximum lumens of 1000 in the lowest setting (10 lumens) you can expect 140 hours, and 1 hour and 10 minutes on max when using a 3000mah battery. When it comes to 18650, it is generally considered a good idea to stay away from Chinese batteries as they often make great claims and deliver poor results. Many of the big electronics manufacturers like Sanyo, Sony, Panasonic, and Samsung make their own 18650 batteries and these have consistently proven to deliver what they promise.
The 18650 is a BIG battery, however, and while it looks like a AA or AAA you must know that it is almost twice the size of a AA battery. It measures 18mm by 65mm hence the name 18650. In order to use the 18650 your device must have been built for it. These have tons of battery as they are huge and they are also rechargeable which makes them a top pick at Vincenox.
Li-Ion and NiMH
Li-Ion and NiMH batteries, when found in headlamps, are often non-replaceable and you may never know exactly what quality battery you are getting, but if you purchase form a trusted manufacturer you can realistically expect to get a quality battery. As they are not replaceable, however, they will more typically be used in headlamps where the user might not need to depend on them for days on end since a readily available power source would be needed to recharge them, usually via USB cable. The lack of a replaceable battery also makes the headlamp’s life span shorter as it is dependent on the battery.
Non-Rechargeable Batteries
AA and AAA batteries are the bread and butter of the non-rechargeable battery world. They have been around for a long time and can be purchased almost anywhere thus making them the most reliable and easy to use. These non-rechargeable batteries are also known as alkaline or single-use batteries. Single-use batteries do exactly what the name describes: when they run out of power you have to have another set ready to go because there is nothing you can do with them. Recycling the batteries is certainly possible but unfortunately there are fees that come with this service. Nevertheless, these batteries are cheap, plentiful, and immensely reliable if purchased from a good manufacturer.
Rechargeable Batteries
Now we step into the world of the ever-popular rechargeable batteries. More and more we are seeing 18650, Li-Ion, and NiMH batteries in the devices we use in our day to day lives. These batteries will almost certainly cost more upfront, but you will get to use them for many charges in their lifetime and will DEFINITELY be worth it in the end if your headlamp or flashlight is built for them.
18650
Most 18650 batteries have a lifetime of 300-2000 charge cycles, but this is depending on your personal use and charging habits. These batteries are used in high-drain devices since they have superior capacity and excellent discharge rates. 18650s are often charged via USB while they are inside of the device you are using them with and you will not have to worry about purchasing an external battery charger UNLESS you have multiple batteries that need to be charged frequently. 18650 batteries are a Li-Ion rechargeable battery and are also known as 18650 cell batteries.
Li-Ion
Li-Ion batteries are widely used in rechargeable headlamps and flashlights as they are reliable, long lasting and can easily be built into the devices. When we refer to Li-Ion devices we are speaking of the headlamps and flashlights containing built in batteries that are not meant to be replaced. These are seen more and more as time goes by, but they have one big downside: these batteries are non-replaceable and if you are the type of person that does not lose things easily, your headlamp might outlive its battery. The positives are numerous, however, and include a light weight, long operating times, quick recharge times, and many recharge cycles depending on manufacturer of course.
NiMH
Nickel Metal Hydride batteries are a variant of the AA and AAA batteries. These are essentially AA/AAA batteries built for devices with a higher power consumption. Whereas an alkaline AA/AAA battery will be great in a remote control or clock, a NiMH battery will perform better on a device like a headlamp or flashlight. Most alkalines are not rechargeable but come with a slow discharge rate while NiMH batteries are rechargeable, but the discharge rate can be quite extreme at 1% daily making these batteries less useful in storage or long-term use devices.
Tips For Longer Battery Life / Battery Safety
- Never throw batteries in a fire. This is a recipe for disaster as they can rupture and let out all kinds of crazy contents.
- Extreme weather can greatly affect the performance of a battery. If you find yourself outdoors, in the cold, do your best to keep your batteries or devices with batteries near your body to keep them warmer. If you are in a hot environment/season, do your best to keep them cool.
- Think of batteries like food and try to get the freshest batch if at all possible
- If you have not used your NiMH batteries in over a week, it is best to recharge them before use in order to get the most out of them as they tend to lose their charge quickly
- Do not mix brands or chemistry in the same device. Why? Different levels of charge can cause weaker batteries to overheat and rupture or leak
- Remove batteries from a device that will not be used for a while in order to mitigate the inevitable drain that occurs to batteries
- If you need power for a long time, choose a high-capacity battery over spares as they will both deteriorate over time anyway and your spare won’t last much longer than your daily driver.
- Do not store batteries in a pocket or container with metal objects like coins as this can short-circuit a battery leading to, once again, high heat or rupture