Super Powered: Battery Basics for Firearm Accessories
April 14, 2015
It's hard for me to wag my finger at other shooters for not having a basic understanding of the batteries that power their shooting accessories without feeling like a hypocrite. Until I started delving into the various facets of battery selection and function, I had only the most basic understanding of the various power sources that kept my rangefinder, optics, lights, lasers, thermal camera, chronograph and other shooting accouterments working properly.
Like many shooters, my basic knowledge consisted of what type of battery I needed to power each of these accessories and where I could purchase them. But when you stop and consider just how much of the stuff we shooters use runs on batteries, it makes sense to take a closer look at these power sources.
Understanding how batteries work can help you save money in the long run. Start by purchasing a battery that offers you the longest run life and then learn how to handle it properly to prolong its life. That doesn't just mean finding the cheapest batteries; in fact, several of the experts I interviewed made it very clear that trying to scrimp on batteries can cost you a whole lot of money in the long run if your selection damages a very expensive item like a tactical flashlight or a laser.
Most of us who simply dump a fresh pair of AAs in a flashlight now and then don't have an appreciation of the complex nature of batteries or the advanced physics and chemistry that goes into battery production. Here are some battery basics that will help you understand your options when it's time to power up.
Lithium vs. Alkaline vs. Silver Oxide
Lithium batteries have a number of advantages over standard alkaline batteries. According to Joseph D'Ambrosia from LaserMax, "Lithium batteries provide a higher charge longer and weigh 40 percent less than alkaline of the same size. That's the reason they cost more."
Aaron Moore from LaserLyte says that their green Center Mass lasers use Lithium batteries because, "the power demands required to run a green laser is high, so it meets those power requirements."
In addition to packing more power into a smaller package, Lithium batteries have an improved shelf life. Burris' Lori Yunker said that another important feature of lithium batteries is that they do not expand and contract as much as alkaline batteries, and that results in fewer problems with leaking and more consistent contact points. In fact, Yunker, as well as Aimpoint's Kristi Drawe and Crimson Trace's Director of Engineering Eric Petterson all listed the lithium battery's ability to withstand wider variations in temperature as an important factor (This is why the military uses lithium batteries in several applications). Alkaline batteries are, of course, cheaper and more widely available.
Another option is silver oxide batteries. LaserMax's Joseph D'Ambrosia says: "We use silver oxide batteries in our products. They have a 10-year shelf life and will reconstitute themselves a little when shut off. Silver oxide batteries are viewed as superior to lithium or alkaline because they will not corrode. They're fully encased in metal, whereas Lithium and alkaline are coated with paper and foil. That is why they can leak. With our products we can't accept any potential for battery leakage. Moreover, silver oxide batteries can easily provide the high voltage in a small package needed to fire a laser."
Rechargable vs. One-Time Use
Some products, like FLIR's Scout thermal imaging equipment, can use either rechargeable or one-time use batteries, and this is largely a matter of personal preference.
According to Surefire's website, you can expect about half the runtime from rechargeables that you'll get from disposables, but rechargeable batteries don't require you to have a bunch of extra batteries on hand at all times. Also, if you're really out in the boonies, you may not have electricity to recharge batteries, so that means that one-time use batteries are the best options.
There's also a question of internal versus replaceable batteries. FLIR's Haley Ellison says that's largely a matter of personal opinion:
"The first (and most important for some users) advantage to replaceable batteries is that they can be readily changed in the field. Second, the camera can be freely used while spare batteries are being charged. Internal batteries have a number of benefits as well; battery connection is usually more robust. There's less chance of a disconnect due to mechanical shock (recoil, etc.), fewer sealing surfaces in the enclosure, reducing the number of potential leak paths, more efficient use of battery power, less energy lost due to weak contact points and the internal charge circuitry is optimized for the battery. There's no need to carry spare batteries, and fewer batteries going into landfills (compared with disposables). You can also use external charge devices like solar chargers if there is no access to AC power for extended periods of time."
Manufacturing rechargeables requires the use of harsh chemicals, and for that reason, the bulk of rechargeable batteries are made in places like China. According to D'Ambrosia, disposable batteries don't require these same chemicals and can be made in the USA.
Preserving Battery Life
Changing batteries more often than necessary is a hassle and can be expensive. There are a number of ways that you can improve battery runtime, and this starts before the battery is even off the store shelf. Not all batteries are created equal, so buying a premium brand battery truly does offer serious advantages, and it is money well spent.
"The capacity of the batteries can vary between manufacturers," says Nick Leininger, electrical engineer for Viridian. The resounding advice that most of the experts polled shared regarding improved battery life was to buy batteries that are of a high quality.
But there are other things you can do to preserve battery life as well. Advanced circuitry like Aimpoint's ACET system will get more battery life out of standard batteries, so battery life can be affected by the product itself. Lithium batteries can also improve battery life, and Lori Yunker says that lithium AAs can last up to 5,000 hours in the company's AR-1X prism sight, while disposable AAs last only 900 hours.
Temperature also plays a major role in battery life, so avoid extremes, especially heat.
"Consumers can prolong battery life primarily by keeping them stored in a cool, dry place," D'Ambrosia says. "Temperature extremes are never good for any product, but batteries in particular are highly susceptible to heat damage and must be protected from heat and direct sunlight. Using batteries when you need them, and being sure to turn them off when you don't, is a no-brainer way to ensure their life is prolonged."Aaron Moore says that batteries have a life span and need to be changed annually in many cases.
Batteries can be dangerous if handled improperly, so be absolutely certain that you are using the right battery for your equipment. According to Surefire's website, using batteries that are not intended for use in a specific product can result in damage, fire or even explosion.
Also, be sure not to purchase counterfeit batteries (For many, it's best to stick with major name brands), and never leave batteries loose in pockets, bags or purses, especially if there are metal parts or other batteries, as this can cause a variety of problems like overheating. Never attempt to recharge disposable batteries, as this can result in the batteries exploding or catching fire.
It's amazing just how much technology is packed into every battery we use. Likewise, it's amazing how little most of us actually know about these power sources. Shooters and hunters rely on a wide array of electrical equipment — trail cameras, chronographs, lasers, flashlights, illuminated optics and more — so it makes sense to familiarize yourself with the most basic functional element of those products.
Having just a basic understanding of how batteries operate will help you preserve battery life, select the best power source for your equipment and prevent injuries and damage to valuable gear.
Common Battery Types
Uses: Cameras, lights, optics, laser devices
Advantages: Small size, high weight/output ratio
NiMH (Nickel-Metal Hydride) AA Rechargeable
Uses: Rangefinders, lights, cameras, thermal imaging
Advantages: Rechargeable, affordable, less waste
AA Disposable Alkaline
Uses: Cameras, rangefinders, thermal imaging
Advantages: Inexpensive, commonly available
CR2032 3V Button Cell Lithium
Uses: Lasers, optics
Avantages: Long shelf life, compact size, high power output
Uses: Cameras, Lights
Advantages: Long shelf life, compact size
Uses: Chronographs, Radios
Advantages: Inexpensive, widely available
Silver Oxide 377/392/393
Uses: Compact handgun lasers
Advantages: Extremely compact, low weight, long shelf life, high output.