Flashlight Battery Current Draw
Today, nearly all serious tactical flashlights run on CR123A lithium batteries and for good reason. Compared to other batteries CR123A cells provide higher voltage, greater energy density, lighter weight, expanded operating temperature range, longer storage life, and more. Like all batteries, however, CR123A’s have limitations and must be operated within engineering parameters to ensure safe and reliable performance. As noted in last month’s blog, Lumen Wars, many flashlight manufacturers, wishing to produce products with the highest possible lumen output, push components to the absolute limit. One of the limits that is all too often exceeded is the electrical discharge current of batteries.
USA-Made CR123A batteries (which are all made by Panasonic and are identical except for their wrappers; Chinese-made batteries should never be used!) have a maximum discharge current of 1.5 amps with a “pulse” allowance that permits up to 3.5 amps to be drawn for a very short period of time. Responsible engineering demands that products using this power source never exceed such specifications. Unfortunately, many of the most popular flashlights on the market, including those from the biggest brands in the industry, exceed these limits, sometimes by a large margin.
Although measuring battery current draw can be done quickly and easily with a simple ammeter or multimeter (see video), it is seldom considered by consumers. It is not prescribed by the ANSI FL1 Standard that governs flashlight ratings so manufacturers rarely, if ever, publish current draw data. Although current draw is largely ignored, it is an extremely important factor for both reliability and safety. While pushing circuit-board-level components beyond specifications will significantly reduce dependability, exceeding the current-draw limits of lithium batteries not only sacrifices reliability but can be downright dangerous. When CR123A batteries are discharged beyond their maximum specified rate, a real risk of explosion exists with the potential to cause significant injury to persons or property in the immediate area.
Engineering specifications exist for good reason. When properly observed, they ensure that products are safe and reliable. Unfortunately, when a specification, such as battery current draw, is not readily known to consumers and not acknowledged by industry standards, some manufacturers will violate them with impunity. It is therefore necessary for the savvy consumer to measure battery current draw themselves. Fortunately, such measurements are simple and easy to take although one must physically obtain a specimen to measure. Should a customer find that their CR123A-powered flashlight exceeds the 1.5 amp limit, it may be time to explore the retailers return policy.