Comparison Fenix UC30 vs Kosmos ACCU678S-LED

General type of flashlight.

Hand lamps for general use are divided into full-size and compact. However, in addition to this, on the market you can find many models with a narrower specialization and/or specific design and mounting features: headlamps ; touring devices, including self-contained dynamo lights, L-shaped lights, and diving models; powerful hand lamps and ultra-compact key chains ; auxiliary lighting systems ; as well as underbarrel models and baton flashlights widely used in law enforcement agencies. It should be noted that one model can belong to several types at once. For example, most underbarrel flashlights are equipped with a removable mount for mounting on a weapon, and without such a mount they turn into hand-held or hand-held compact ones; and L-shaped models, in principle, are not an independent type of flashlights — most often this is a design feature of hand-held compact or head-mounted devices (or even models that combine both of these applications).

— Manual. Full-size hand-held flashlights over 20 cm long and weighing over 200 g represent a kin...d of "middle class". They are designed for those for whom compactness does not play a decisive role and functionality is important first of all. Such lights can carry on board more than 1 LED and powerful power supplies, providing a good luminous flux; they are often supplied with various additional functions.

— Manual compact. This type of flashlight is somewhat larger than key fobs, but can still be classified as compact devices: hand-held compacts look like a tube up to 20 cm long and weighing up to 200 g. They rarely install more than one LED, but their dimensions and weight already allow the use of fairly powerful sources supply, which has a positive effect on the characteristics of the luminous flux (see "Maximum luminous flux"). In addition, a number of additional functions can be used in this type of flashlight, such as focus and brightness adjustment (see below).

— Lantern on the forehead. Flashlights designed to be mounted on the head — usually with special elastic straps that can be adjusted to fit. Mounting features impose restrictions on the weight and dimensions of the lantern, which affects the functionality. When purchasing such a flashlight, it is worth considering that high brightness in this case may be a disadvantage — if you need light to work with objects in close proximity, excessive brightness quickly tyres your eyes. In this case, it may make sense to pay attention to models with brightness control (see below for more details). Typically, such models have the ability to adjust the angle of the beam, but the possibility (and features) of such adjustment needs to be specified separately.

— L-shaped. Lanterns in which the beam of light is directed perpendicular to the body; the body itself, usually, has a cylindrical or close to it shape. Most of these models, according to the main format, belong to hand-held compact ones, and many also allow use in the headlamp format (see above for both). Anyway, L-shaped lanterns with the possibility of manual use have a characteristic clip on the body — on the opposite side of the lamp. Such a clip allows you to hang the device on a belt, the edge of a pocket, an element of an unloading vest or other overalls, etc.; in this case, the light beam will be directed forward, the vertical position of the case will ensure the stability of the device, and the user's hands will be free. (Note that the first L-shaped lanterns designed for such wearing appeared as an element of army equipment — back in World War II, the US military fully appreciated the merits of such a design).
As for the forehead installation, in such cases the body is placed horizontally, and its mount is made movable. Turning the lantern in such a mount, you can set almost any angle of the beam; at the same time, regardless of this angle, the position of the lantern remains equally stable (whereas in some headrests with “heads” of an inclined design, such a “head” may tend to roll forward as the mount wears out).

— Manual lamp. The most powerful type of hand lamps, which can even be called "hand spotlights". Most of these devices are designed to give out a long-range and at the same time sufficiently thick beam of light — much wider than in many other types of lanterns. Actually, the illumination range of hand-held lamps often exceeds 100 or even 200 m, while the large beam width makes it possible to very effectively detect individual objects even at such large distances. Another, less common type of such devices are models that have a short range, but are capable of illuminating a vast area.
Anyway, flashlights of this type turn out to be quite large and heavy, so initially they are not designed to be constantly carried with you (although even one and a half to two hours with such a device in your hands usually do not cause much discomfort). It is worth paying attention to hand lamps in cases where the effective detection range (or bright illumination of a vast area) is of the most fundamental importance to you. In particular, such devices are very popular in rescue services: a powerful beam of a "portable searchlight" is indispensable for search operations at night. Also among the lamps of this type there are so-called "inspection" models, well suited for inspecting machines, industrial equipment, communications (cables, pipelines), etc.

— Tourist. Tourist lamps are mainly lanterns that were originally intended for organizing lighting in a camp, at a halt, etc. Such devices provide diffused light with a coverage of 360 ° horizontally and most often allow installation directly on the ground. In addition, most of them have a hook for hanging, sometimes supplemented with a built-in magnet (see below for both). Thus, such a lantern can be mounted on a tree branch, under the ceiling of a tent / awning, etc., significantly expanding the area of illumination — or hung on a backpack or other equipment, illuminating the path for several people at once.
Most tourist lanterns have only this specialization; however, there are also models that allow other applications. Usually these are hand-held compact devices of a special design — with a retractable diffuser made of white matte material. Such a device allows you to turn the directional beam into diffused light with full horizontal coverage; and when such a beam is not needed, the diffuser can be hidden in the housing. However, some of the more traditional travel models also have a folding design — it makes it easier to carry after hours, especially if the device needs to be hidden in a backpack or bag with other things.

— Dynamo flashlight. Lanterns equipped with a built-in generator (dynamo) that generates energy due to the user's muscular strength — usually for this you have to swing or twist a special lever. Thus, it is possible to recharge the built-in battery even in the absence of power sources (and such lights most often work from batteries). Such features are especially relevant for those who often have to be "far from civilization": tourists, military, researchers, etc. At the same time, dynamo lights can have different specializations — compact, tourist, etc.

— For diving. Lanterns originally designed for diving and long stays at great depths — usually from 50 m or more. Such models, by definition, have a sealed waterproof housing (see "Dust and water protection"). In addition, diving lights are often designed with specific features designed to provide additional convenience and safety. For example, the body can have bright colours or additional inserts that increase visibility under water, as well as be made of lightweight material so that the flashlight released from the hand floats to the surface and does not sink. Often, the device is supplemented with a carabiner for attaching to equipment or a hand strap (see "Complete set"). It is because of these additional features that not every flashlight with a high level of water protection is considered diving. Therefore, it is worth looking for a lamp specifically for diving among the models of this category.

— Auxiliary lighting. Lanterns designed to organize additional stationary lighting where there is no light or it is not enough. In a sense, such models are similar to tourist camping ones (see above), they can also be used in a parking lot or in a tent. However, the matter is not limited to this: many auxiliary lamps are originally designed for use in workshops, garages, etc. Some of them can also be hung on the open hood of a car, which can be very important for field repairs. But such models are not designed for carrying in hands: it is technically possible, but not very convenient.

— Trinket. This category includes the most compact models: their weight, usually, does not exceed 50 g, and the length is 10 cm. Hence the name — most of these lanterns can be worn instead of a keychain on a keychain. Actually, the convenience of wearing is the main advantage of key rings: you can always have such a flashlight at hand. The main disadvantage is low power: key fobs are usually equipped with one LED (see "Number of diodes"), and any "solid" power source in a compact case will not fit. At the same time, such lamps are quite enough for simple everyday tasks — for example, to illuminate the road on an unlit section of the street or find a keyhole if a light bulb has burned out in the entrance.

— Underbarrel. Flashlights designed to be mounted on a weapon are most often under the barrel, but installation on the side is also technically acceptable. Many of these models are essentially hand-held compact flashlights (see above), supplemented by a removable weapon mount (or the ability to install on such a mount — see "Packaging"), as well as, in most cases, a remote button (see below) ; however, there are also purely underbarrel models in which the mount is not removed. In both cases, the mount is usually designed for a standard Weaver / Picatinny rail, but this point needs to be specified separately. This also applies to the possibility of full-fledged use with firearms: the fact is that some underbarrel lights are intended for airsoft drives and are simply not designed for powerful recoil.

— Lantern-baton. Lanterns with a baton or baseball bat body and are strong enough to strike. Such a flashlight can be a very useful addition to the equipment of a watchman or law enforcement officer. Note that some so-called patrol lights, hand-held lights in a large and durable body of traditional design, also allow the use as a “percussion tool”. However, for them, such an application is an extreme case, while baton lamps are initially created as reliable and impact resistant as possible. Therefore, patrol models in our catalog are still not assigned to this category, but to ordinary hand lamps.

Model of the LED(s) used in the flashlight. Knowing the exact name of the LED, you can find its detailed characteristics and evaluate the capabilities of the flashlight. In addition, this information may be useful when replacing a failed diode.

Note that the LED model is indicated mainly if it is a high-quality LED with advanced characteristics. Such light sources are produced by different manufacturers, but the most popular in modern flashlights are products from Cree with its series Cree XM, Cree XP, Cree XHP. Here are some of the most common LEDs from this brand: Cree XP-L, Cree XM-L2, Cree XP-E, Cree XP-G, Cree XM-L T6, Cree XM-L2 T6, Cree XM-L U2, Cree XM- L2 U2, Cree XP-G R5, Cree XP-G2 R5, Cree XP-E Q5.

Cree XM-L and XM-L2 series diodes are used in high-power flashlights. XP-G and XP-G2 are used in relatively small models. They produce a beam of light in the shape of a circle with a darkening inside when using a reflector to focus. XP-E and XP-E2 are a godsend for small items with an evenly f...ocused beam and even illumination on the sides. The number “2” in the designation of the diode model indicates increased brightness (compared to the basic modification). The XHP series is also gaining popularity - the LEDs in this line more than double the light flow. At the same time, they are compatible with standard printed circuit boards and optics. The numerical prefix 35/50/70 in the name of XHP diodes indicates the dimensions of the housing.

Along with solutions from Cree, high-quality LEDs from the American manufacturer Luminus are often found in flashlights. Its range includes both inexpensive diode options for budget flashlights and advanced LED light sources with high luminous brightness and luminous flux intensity for the most powerful flashlights.

A separate case is represented by diode plates made using COB technology (chip-on-board, that is, “chip on a board”). Such plates are arrays of a large number of miniature light sources, soldered directly into a printed circuit board at a short distance from each other and filled with a special composition; This composition performs two functions at once. First of all, it protects the LEDs from contact with air, which increases their service life; In addition, the coating effectively diffuses light, creating a uniform luminous flux.

Note that previously, to create LED arrays, SMD technology was mainly used, with individual LEDs soldered onto the surface of a printed circuit board. However, COB is a more modern and advanced option: this technology allows small but bright light sources to be placed at very high densities, achieving powerful lumen output even with small array sizes. In addition, SMD boards did not provide a protective coating.

In general, it makes sense to pay attention to flashlights with COB plates if you need a high-quality source of diffused light. As a result, such diode arrays are especially popular in travel lanterns and auxiliary lighting (see "Type"), but can also be used in other varieties - from ultra-compact key fobs to high-power hand-held lamps.

The number of LEDs (see "Lamp type") provided in the design of the lantern.

At first glance, the more LEDs, the more powerful this model. However, in fact, things are not so clear cut. Firstly, one high-end LED may well provide more light output than several inexpensive diodes. Secondly, modern luminaires can use both traditional LEDs and arrays of numerous miniature diodes on a common basis. Such arrays can be implemented using SMD technology or more advanced COB; the differences between these options are described in more detail in the Diode Model section, here we note that a solid SMD or COB plate is also considered to be 1 LED — despite the fact that in terms of luminosity it can exceed conventional LEDs by several times, or even orders of magnitude.

Thus, it is hardly worth directly evaluating the brightness and efficiency of the flashlight by this parameter. But what the number of diodes often directly affects is reliability: most “repeatedly charged” lamps are able to continue working even if some of the diodes fail. In addition, in some types of flashlights — in particular, tourist models and hand-held diffused lamps (see "Type") — each LED illuminates a separate sector, and together they cover a full 360 ° horizontally.

The maximum luminous flux provided by the lantern.

Luminous flux (denoted in lumens) can be described as the total amount of light produced by an LED or other light source and distributed in all directions where this source shines by itself (without lenses, reflectors, etc.). In fact, this means that the capabilities of the flashlight depend not only on the luminous flux, but also on the angle of illumination (see "Angle of illumination (light)"). For example, a relatively weak stream can be concentrated into a narrow beam, providing good range; and a large number of lumens will inevitably be needed to effectively cover a wide area.

Note that the coverage angle is not always specified in the characteristics, and even with such data it is difficult to immediately assess the real capabilities of the flashlight. Therefore, for such an assessment, it is best to use information about the actual illumination range (see below), and also take into account the general type of device (see above). For example, for the same number of lumens, a handheld flashlight with a reflector to form a directional beam will give a noticeably greater range than a tourist lamp with 360 ° coverage.

It should also be borne in mind that the high brightness of the flashlight is far from always justified, and it is worth choosing according to this parameter, taking into account the actual conditions of use. S...o, when working at short ranges, bright light can become a hindrance: it tyres the eyes and can blind others. In addition, an increase in brightness usually requires more powerful sources of both light and power, and the weight and dimensions of the lantern increase accordingly.

The maximum range at which the flashlight provides any effective illumination of objects. Different manufacturers have different criteria for this efficiency when measuring ranges, and therefore it is only possible to unequivocally compare among themselves in range only models of one manufacturer. At the same time, this parameter allows us to compare models from different manufacturers with some certainty: for example, flashlights with a lighting range of 15 m and 100 m will clearly belong to different range classes, regardless of manufacturers.

Note that the range of illumination depends not only on the maximum luminous flux provided by the lantern (see above), but also on the features of its design: the narrower the beam is provided by the reflector of the lantern, the greater the range will be, and vice versa — scattered light does not spread far. Some models allow you to adjust the beam width depending on the requirements of the situation (for more details, see "Adjusting the focus").

It is also worth bearing in mind that models with the same claimed lighting range can cover different spaces. For example, a hand lamp (see Type) with a reflector diameter of 20 cm will be able to provide a wider beam than a conventional hand lamp with a 5 cm reflector. And although in both cases the objects that fall into the light spot will be illuminated in the same way, however, in the first case, the size of the spot itself will be larger, and the actual efficien...cy of the flashlight will be correspondingly higher (in light of the fact that it is easier to "feel" individual objects with a wide beam, especially at a considerable distance).

Maximum runtime of the flashlight without changing batteries or recharging the battery.

Note that in models with brightness control, this time is indicated for the most modest and, accordingly, economical mode. For example, in a flashlight with a maximum luminous flux of 1000 lm, the claimed operating time of 20 hours can be achieved at a brightness of only 30 lm, and at maximum battery life may not exceed half an hour. These nuances should be clarified according to the detailed characteristics. However, also note that additional modes of operation (see below) are not taken into account in this case: for example, if the flashlight from our example in SOS mode can operate for 30 hours, the characteristics will still state 20 hours.

It is also worth bearing in mind that for models with replaceable batteries, the actual operating time will also depend on the quality of such batteries. For example, for flashlights for AA and AAA elements, battery life is most often given when using high-quality alkaline batteries; if instead of them inexpensive saline ones are used, the operating time may be several times shorter.

In general, when choosing a flashlight according to the maximum operating time, it does not always make sense to focus on “long-playing” models: they often have either low power or impressive weight / dimensions, and the price can significantly “bite”. Flashlights with a long battery life will be useful first of all to those who have to s...tay “away from civilization” for a long time: extreme tourists, rescuers, military, etc. And for most everyday tasks in a modern city, and even for trips to nature for several days, up to 10 hours is enough.

The number of brightness levels provided in the flashlight design. Most modern models have one level of brightness, but there are models with the ability to adjust. Several levels of brightness allow you to choose the best option for a particular case: for example, to view a small room, you can reduce the brightness and save battery power, while in a large warehouse you may need full power of the flashlight. Accordingly, the more brightness levels are provided in the design of the flashlight, the wider your options for choosing the best option will be.

Also note that in addition to step-by-step brightness adjustment, with fixed levels, modern flashlights can also be used with smooth adjustment. It is detailed below; here we note that the stepped format is technically simpler, cheaper, and therefore is used much more often. And in individual lamps, these options are combined — for them, the characteristics indicate both the number of individual brightness levels and the presence of smooth adjustment. The specific way to implement such a combination may be different. For example, a brightness control ring can have several fixed levels with clear values, and the ability to set any intermediate position between these values; the main mode of operation with smooth adjustment can be supplemented with a fixed level of reduced or increased brightness; etc.

The number and types of additional modes of operation provided for in the flashlight.

Additional modes include all modes in which the flashlight operation format differs from the standard “constant luminous flux in the visible range without pronounced coloration”. Namely strobe, SOS, beacon, flicker, light, low / high beam, infrared (IR), ultraviolet (UV), red light, blue light, green light, etc. More details about each:

- Stroboscope. Fast flashing mode - several flashes per second. One of the most popular applications of this function is disorientation of the enemy in an extreme situation; in light of this, a stroboscope is often provided in underbarrel flashlights (see "Type"), as well as manual models of "tactical" specialization. In addition, fast blinking is well suited to distinguish yourself on the road - especially in cloudy weather or at night: such a light is much more visible than constant light, including with peripheral vision. At the same time, we note that when using a stroboscope, some caution should be observed: due to the specific effect on the p...syche, this mode can provoke exacerbations of certain diseases - for example, seizures in patients with epilepsy.

— S.O.S. The mode of operation is "three short flashes - three long - three short", which corresponds to the international signal "please help" (letters SOS in Morse code format). This eliminates the need to send such a signal manually and allows you to leave the flashlight to work autonomously, and take care of more pressing problems (which often accompany situations that require the "SOS").

— Low / high beam. Possibility to switch between far directional beam and near diffused light. This switching is most often accomplished by using multiple sets of LEDs; at the same time, in some models, each of these sets is responsible for its own mode, in others, all diodes work in the high beam, and only a part of them work in the low beam.

— Infrared (IR). Illumination in the invisible infrared range. It is used, in particular, to improve the efficiency of night vision devices and IR sights. Note that many of the LEDs responsible for this mode also glow in the visible range (red light) during operation; however, this glow is quite weak and, as a rule, is noticeable to the human eye only when looking directly at its source from a short distance.

- Ultraviolet (UV). Illumination in the ultraviolet range is mainly used to identify objects and traces that are invisible under normal lighting. One of the most popular ways to use this feature is with a makeshift currency detector: most modern banknotes have markings that glow under UV light. Also, such light can be used to detect inscriptions with “invisible” ink (including marks on the same banknotes), some biological (for example, blood) and chemical liquids (in particular, UV-sensitive compounds can detect leaks in pipes and liquid contours), etc. Note that the UV emitter usually glows in the visible range - with a characteristic bluish tint; this allows you to accurately determine whether such a light is on or off.

- Red light. One of the more popular complementary colors in modern flashlights; can be used both in combination with blue and green (in the so-called RGB models), and as the only auxiliary shade. One of the features of red light is that it practically does not affect night vision, does not penetrate through the eyelids, and even after complete darkness does not blind the eyes. This makes such lighting the best option, for example, for clarifying map data during a night hike, when you need to quickly restore vision after turning off the light, or for emergency lighting in a sleeping room, where you need to see the environment and at the same time it is undesirable to disturb sleeping people with the light. . Another way to use red light is signaling: this light travels farther than blue or green, and stands out prominently against most landscapes and man-made objects. Hue change can be carried out both due to the light filter on the main light source, and due to a separate LED.

- Blue light. One of the shades used in the main three-color "RGB-lanterns" - along with red (see above) and green. This light is intended mainly for situations where you need to effectively illuminate the space in front of you, but it is undesirable to use ordinary white light. Human vision is most sensitive just to blue and green shades; therefore, a relatively weak blue light flux allows a large amount of detail to be revealed. And in some situations, such lighting can be even more effective than white. For example, if at night a white lantern is pointed at a light object, then the space behind this object will be hardly noticeable due to the bright reflected light; and a weak blue light will evenly highlight both the "foreground" and the "background". But using this shade at high brightness, on the contrary, is undesirable - reflection from bright blue light will dazzle even more than from white, and even more so red. And if a blue beam, even a weak one, hits directly into the eyes, it will instantly knock out night vision, and it will take quite a long time to restore it.
Note that the choice between blue and the similar green (see below) depends on the specific situation: different shades may be optimal in different situations.

- Green light. Hue, most commonly used in tri-color RGB lights, but sometimes used as the only complementary color. In many ways it is similar to the blue described above - in particular, in some situations, a weak green light can clearly reveal details that are invisible in other shades (even under the same blue light), but high brightness is undesirable for such a beam. In addition, this color has its own specific feature: many animals almost do not react to green light, so it is especially convenient for hunting.

- Lighthouse. The mode of infrequent flashes with a repeating amplitude, most often at a relatively low brightness (with some exceptions to the rule). In some models of lanterns, you can even meet more than one version of the lighthouse. The mode is designed to detect and observe the user at a distance; at the same time, the beacon not only consumes battery power more economically than a constant light of the same brightness, but is also better visible from afar. We also note that in headlamps, the flicker mode performs a similar function (see below).

- Flicker. In this mode, the flashlight emits short pulses or shines with a variable, "pulsating" brightness. This format of work is not intended to illuminate the surrounding area, but to make the user more visible to others: a person reacts to flickering light reflexively, even if its source is far in the peripheral vision zone. The flicker mode will be useful primarily on the roads - for example, when walking or cycling at night: in the same city, such a warning for surrounding drivers will not be out of place, and there is no need to talk about dark country roads.

— Red blinking (red blinking, red beacon). This mode allows you to make the flashlight as noticeable as possible: the red light, especially the flashing one, catches the eye even in the daytime. And in the dark, this shade is also useful due to the fact that it does not harm night vision (for more on this, see "Red Light" above). But the specific specialization of the red flashing may be different, depending on the specialization of the flashlight. For example, in tourist models (see "Type"), this mode allows you to give a signal, indicate the location of the camp, collection points, etc.; and in headbands, it is used to highlight the user on the road and make him as visible as possible to others (primarily for car drivers).

- Lamp. The function is found, as a rule, among hand lamps and in tourist models of flashlights (as an addition to the main directional light). In fact, we are talking about a scattered light mode - as opposed to a directional beam that provides the main light source with a reflector. Diffused light does not differ in range, but it allows you to cover a significant space - for example, to illuminate an entire room.

- LCU. Laser pointer mode: the flashlight emits a laser beam, the mark from which points to the intended point of impact. It makes sense to provide for such a regime only in underbarrel models (see "Type").

Note that this list is not exhaustive: modern flashlights may provide for other, more specific modes of operation. In such cases, the features of the functionality should be clarified according to the manufacturer's documentation.

The type of batteries used in the flashlight.

The most popular nowadays are replaceable cells in sizes AA, AAA, C, D and CR123, replaceable lithium-ion 18650 batteries, as well as branded batteries. At the same time, some models from the latter category are designed for standard batteries for power tools and are supplied without their own power sources at all; such devices are commonly referred to as the so-called building lights. And here is a more detailed description of the different types of food:

— AA. Batteries, colloquially known as "finger-type" batteries. One of the most common sizes nowadays; such cells are available both as disposable batteries and as rechargeable batteries, and they are sold almost everywhere. On the other hand, in modern flashlights this option is less common than the more miniature AAA — the development and reduction in the cost of LEDs has made it possible to effectively use more compact power supplies.
Note that "finger" batteries can vary markedly in capacity; accordingly, the battery life of a flashlight with such a power supply will be different — depending on the brand of batteries (accumulators) used. Also note that the use of such cells (like most replacement batteries) is inevitably associate...d with additional expenses: you will either have to regularly buy fresh disposable cells, or spend money on a set of batteries with a charger.

— AAA. They are also "little finger" batteries — by analogy with the "finger" ones described above. They are also available in different formats — both batteries and accumulators — and in different capacities and prices. They are smaller than AA, which is why they are generally inferior to them in terms of capacity. On the other hand, modern LEDs often have enough of such power; and compactness is often more important than high capacity. Therefore, AAA elements in modern flashlights are much more common than AA.

— C. 1.5-volt cylindrical batteries with dimensions of 50x26.2 mm; approximately equal in length to AA, but much thicker, due to which they have a much higher capacity. Some time ago they were quite popular, but now they are used extremely rarely — mainly in devices where the dimensions of the case initially allow the installation of such power sources (a typical example is batons, see "Type").

— D. Cylindrical batteries, the largest (61.5x34.2 mm), capacious and powerful among the currently used 1.5-volt power supplies. Similar to the elements of type C described above, they are rarely used, mainly in lanterns that initially assume large sizes.

— CR123. Cylindrical batteries. They have a length of 34.5 mm and a diameter of 17 mm, due to which they resemble a smaller variation of type C, but differ in operating voltage — 3 V. In the battery version, they are marked as CR123A. In general, they are quite rare, mainly in hand-held compact models and key chains, as well as underbarrel flashlights for pistols (see "Type"); however, specifically among these categories, such batteries are quite popular.

— 18650. In general, nowadays, a whole family of batteries is produced that use a 5-digit marking — for example, 14500 and 17650. All of them are made using lithium-ion technology, and have a cylindrical shape and a voltage of 3.7 V; the marking indicates the dimensions of such batteries in diameter and length (see below for more details). Specifically, 18650 (diameter 18 mm, length 65 mm) is the most popular type of such elements — both in general and specifically among flashlights. This is primarily due to the combination of compact dimensions and fairly solid performance. At the same time, thanks to cheaper technologies, 18650 batteries can now be used even in low-cost models — including those initially supplied in the kit. However, anyway, it would not hurt to clarify the complete set of a flashlight with such a power supply separately — and this applies to both the battery and the options for charging it available “out of the box” (for more details, see “Packaging”).
In general, such elements combine the advantages of replaceable batteries and branded batteries. On the one hand, the power source is reusable; when the charge is exhausted, you do not need to spend money on fresh batteries every time; on the other hand, if desired, you can purchase several batteries and quickly change them as needed. And with a separate charger, you can completely reduce work interruptions to zero: while one set of batteries is in use, the rest can be charged.

— Accumulator. This option means that the flashlight uses a branded battery that does not belong to standard sizes (and in many models it is also non-removable). One of the advantages of such a power supply is that the user does not need to spend additional time and money on buying batteries: the power supply is initially supplied in the kit, and when the energy is depleted, it is enough to charge it. At the same time, the delivery set may include both an adapter for an outlet and a car charger (for more details, see "Packaging"). The second advantage is that branded batteries are often more compact and at the same time more capacious than replacement batteries; and in general, such a battery is easier to fit into the design of a flashlight (especially non-standard). Among the key disadvantages of this option, first of all, the impossibility of a quick replacement can be noted — usually, a dead battery needs to be charged, which takes time and a power source. In addition, having your own battery inevitably affects the cost; this is especially noticeable when comparing low-cost models of rechargeable flashlights with battery-powered counterparts. However, the difference in price can quickly pay off with intensive use.
A special case is the so-called "construction" rechargeable lights. They are produced mainly by large manufacturers of power tools (Bosch, DeWalt, Makita, etc.) and use replaceable batteries for tools of the “native” brand as power sources. At the same time, such a battery is usually not included in the kit — it is assumed that it is more convenient for the user to buy a battery on their own, at their discretion (or that the household already has a branded tool and, accordingly, a power source).

In addition, more rare and specific food options can be found in flashlights:

— AAAA. Batteries are even smaller than the "little finger" AAA — 43 mm in length and 8.3 mm in diameter. They are used in some thin compact format lanterns, many of these models resemble fountain pens in shape and size.

— Replaceable Li-Ion batteries with a 5-digit digital marking — similar to the 18650 described above, but differing in size. Specifically, among the flashlights you can find the following form factors of similar power supplies: 10180, 10440, 14430, 14500, 16340, 17650, 21700, 26650, 32650. All of them have a standard voltage of 3.7 V, and the size of the element can be determined by marking: the first two digits correspond to its diameter, the second two to its length (both in millimetres). The larger the battery, the higher its capacity and, accordingly, the power supply.
Separately, it is worth noting that the 14500 cells are identical in size to conventional AAA finger batteries, but differ from them in operating voltage. In some flashlights this difference is taken into account, and they can use both types of power sources (with less battery life and/or brightness when running on batteries). However, in general, the possibility of such a replacement needs to be clarified in each case.

— Series CR****. Batteries — "coins" of a characteristic disk-shaped form based on lithium technology (not to be confused with lithium-ion batteries — in this case we are talking about disposable power supplies). The numbers in the marking indicate a specific size — for example, the CR2032 marking corresponds to 20 mm in diameter and 3.2 mm in thickness. Actually, CR2032 is one of the most popular sizes of such batteries; besides him, you can find CR1220, CR1616, CR2016 and CR2032 in flashlights. All such power sources are mainly used in compact low-power flashlights, in particular, key fobs (see "Type").

— Series AG**. The "AG" suffix with a number (one or two) is used to refer to miniature alkaline manganese type disposable batteries manufactured by Seiko and some other brands. The larger the number in the designation, the larger the size of the battery: the smallest of these elements, AG0, have a diameter of 5.8 mm and a thickness of just over 2 mm, and the largest (of those used in flashlights), AG13, are 11.6 mm in diameter and 5.4 mm thick. The main scope of such elements is miniature flashlights, including key chains.

— Series LR**. In fact, it is a complete analogue of the AG series described above **; the only difference is that AG is a brand name, while LR is used as a common international designation. In addition, there is no clear relationship in this standard between the number in the designation and the actual dimensions of the battery: for example, LR41 is larger than LR58, and LR44 is larger than both of them. Actually, in modern flashlights there are mainly just LR41 and LR44; they are analogues of AG3 and AG13, respectively, and have dimensions (length / diameter) of 7.9x3.6 mm in the first case and 11.6x5.4 mm in the second.

— 3R12. Batteries with a voltage of 4.5 V in a case of a characteristic shape: almost square and flat (70x60x22 mm), with rounded corners and two contact plates in the upper part. They were originally created as batteries for flashlights, but nowadays they are used quite rarely due to their large dimensions, shape features and relatively small capacity.

— PX28L. Compact and at the same time quite powerful cylindrical batteries with a nominal voltage of 6.2 V. They are well suited for working with a powerful load, including bright LEDs, but in general they are not widely used, and therefore they are rarely used in flashlights.

— R20. Another name for replaceable cells in size D is, more precisely, for disposable salt batteries produced in this size (other designations are used for other varieties). Usually, flashlights under R20 are compatible with any type D elements, however, the ability to work with salt batteries (having a lower capacity than alkaline counterparts, and even more so batteries) indicates a good energy efficiency and economy of the flashlight.

— CR2. Relatively small batteries (length — 26.7 mm, diameter — 15.1 mm), originally created for compact "soap" cameras — in the expectation that one such element could replace 2 AA batteries. The designation CR2 is commonly used for disposable batteries, batteries of this size are usually referred to as 15270.

— From the cigarette lighter. Power from the car on-board network through the cigarette lighter (or an auto socket of a similar format) can be found in two types of lamps. The first is hand lamps and auxiliary lighting (see "Type") designed for use with or near the vehicle. Most of these devices only work when connected to the cigarette lighter, and a fairly long (several metres) wire with an appropriate plug is responsible for the connection itself. The second option is miniature models (manual compact type and key rings) of “automotive” specialization. Such devices are equipped with their own batteries and are able to work autonomously, and the cigarette lighter is used to charge the battery — and the flashlight body itself plays the role of a plug (in other words, to charge, just insert the device into the cigarette lighter socket). However, both varieties are rare nowadays: in the case of lamps, the wire significantly limits mobility, and in the case of small flashlights, charging from the car network is not so often required. And even in the latter case, a more practical, versatile and convenient option may be a traditional rechargeable flashlight, supplemented by a car charger (see "Complete set").