Protective functions of modern e-cigarettes
No question, safety is one of the top priorities when vaping! Even the very first regulated e-cigarettes had a package of protective functions on board. Of course, when looking for innovations, manufacturers don't just focus on taste and vapor development, service life or design. Rather, they also address the important questions of security. What has happened in this area so far, which developments have made vaping even safer and more convenient at the same time? We want to take a close look at some relevant protective functions in this article!
Electrical and mechanical protection functions
The absolute majority of the e-cigarettes that are regularly available in Ireland and the entire European Union are regulated, which means that the devices are monitored and controlled by an integrated chip set. This also applies to models on which the user cannot make any settings himself. Many classic protective functions of an e-cigarette, which are now an established standard, such as the puff time limit or protection against short circuits, are regulated via the chip. Such a chip measures the resistance at the evaporator, for example. The information is stored on the chip, which voltage the integrated or replaceable battery suitable for the device can deliver without excessive currents flowing. For example, if the resistance is too low, the mod will no longer emit any voltage (overvoltage protection). The user of a regulated e-cigarette can therefore safely use the device without worrying about Ohm's law. Other, no less important protective functions are of a purely mechanical nature. This includes, for example, the degassing holes in the battery housings, regardless of whether the devices are operated with internal or replaceable battery cells.
Classic and modern protections
Of course, the distinction between what is classic and what is modern cannot be taken as a hard fact. Rather, the perspective is subject to changes over time, which is not only the case in connection with the e-cigarette. Nevertheless, there is a whole package of important and useful protective functions that the first controlled devices in the history of e-cigarettes were already equipped with. They should be considered here as the classic safety features. Other protective mechanisms were only developed over time or even only became possible with advancing technical development or were simply not relevant before. Since many vapers are likely to be familiar with the classic protective functions, we want to focus on more recent developments first and then go into the second part of the text on the established functions.
Modern protective functions of an e-cigarette
The dry burn or dry hit, the scorching of cotton wool that is not sufficiently saturated with liquid due to the heating of the coil, is one of the most unpleasant experiences that a user of the e-cigarette can have. With the iStick Pico Plus Kit, the manufacturer Eleaf presented the All-Time Stable Technology (AST). It prevents the mod from releasing voltage when the tank is empty or the level is too low. This Smart Coil Protection can be switched on as an option and has since been used in a whole range of current Eleaf e-cigarettes. If the AST mode is activated, the device will no longer fire as soon as there is not enough liquid in the tank. A corresponding error message is shown on the display. The process has always worked for devices that work with temperature control. By using austenitic steel for the coils or the mesh of the heads belonging to the corresponding sets, it can now also be used in power-controlled modes. A useful innovation that can save inexperienced users from surprises, but also makes vaping more relaxed and pleasant for old hands!
Experienced e-cigarette users know: If you use regulated mods for exchangeable battery cells, it is - unlike with mechanical devices - crucial to insert the battery or batteries with the correct orientation of the plus and minus poles. Devices with reverse polarity protection simply do not output any voltage as soon as the battery cell is inserted incorrectly. The SmartLoad technology, which was used by the producer FreeMax for the first time in the Maxus 200W e-cigarette, allows batteries to be used in both directions, even with regulated devices. Compared to the classic reverse polarity protection, the feature does not provide any more security, but it combines security with more comfort!
With devices that work in variable wattage mode (VW), the user can freely select the output power of the e-cigarette in a specific range. However, not all evaporator heads available for the respective device may also be fired with the technically greatest possible power. This becomes obvious when a manufacturer offers both atomizer heads for vaping from the mouth to the lungs and heads for sub-ohm vaping with direct lung inhalation for a device: The thinner wires, which are used in the MTL range due to their higher resistance, could be used with Performances in the three-digit range simply burn up in the long run! If you vape in Auto or SMART mode, the mod automatically determines the resistance on the atomizer and optimally adjusts the output power. Voopoo uses this method in almost all devices of recent generations and even uses the smart mode as a standard. If you activate such a device for the first time, the mode is preset. Inexperienced users in particular, who may not even be aware that atomizer heads can only be used in certain power ranges, do not accidentally fire a high-impedance MTL head with too high a power when trying it out for the first time.
The features mentioned above fall within the scope of the electronic protection functions of an e-cigarette. They are controlled by a microprocessor and can be used with devices that are monitored by a chipset. The following examples show that the developers in the innovation centers of the manufacturers have not been idle in the last few years, even in the mechanical protection sector!
In the middle of 2018, GeekVapepresented the Aegis Legend model, the first mod that was waterproof and dustproof according to the former IP67 military standard and also protected against falls and bumps to a special extent. Such protection is achieved, for example, by padding or spring-loaded mounting of certain sensitive assemblies, or by sealing access points such as the charging port in a watertight manner. The classification IP (Ingress Protection) is now used internationally to indicate the degree of suitability of electrical devices for certain environmental conditions. After the great success of the Aegis Legend, other manufacturers also switched to protecting individual models in their series according to IP67. GeekVape itself has since applied the standard to all devices in the popular Aegis series. With the release of the Aegis Legend 2 in 2021, GeekVape will even protect the mods to the next higher standard with IP68 certification. The advantages are obvious: Depending on where and how you use the e-cigarette (outdoor, craft), using a protected device is safer for hardware and vaper!
Under the FEELM Inside label, the manufacturer Smoore presented the first pre-filled pod system in which ceramic is used as the carrier material for the liquid. The advantage of the process: since disposable pods cannot be refilled, you simply vape until the pod is empty. If the cotton, which is stuffed manually, does not reach the bottom of the pod, the above-mentioned dry burn occurs, although there is still liquid in the tank. This source of error is eliminated by using the standardized ceramic heating elements. The FEELM technology is used successfully, for example, in the Easy 4 from SC.
The bottom lock system, used by Eleaf in the MELO 5 clearomizer, for example, is one of the purely mechanical protective functions and makes the use of an e-cigarette much more convenient: If the coil heads are removed from the evaporator, the inlet openings in the chimney are automatically closed mechanically . Changing the head is also possible when the tank is full, without liquid containing nicotine escaping.
The Accidental Press Protection or A-Lock Protection, which GeekVape built into the Aegis Solo 2 and Aegis Mini 2 models, for example, allows the mod to be locked via a slider on the side of the device. This prevents the e-cigarette from being activated unintentionally, for example during transport. Mods can often be blocked or switched off using key combinations. However, A-Lock Protection allows the operation to be performed with just one hand, making locking the device easier and more enjoyable. Unintentionally firing the mod in your pocket is anything but nice, even for 10 seconds, and puts a strain on the hardware. GeekVape has found a simple and practical solution that could make school!
Classic protective functions of an e-cigarette
Experienced vapers should know them, but can refresh their knowledge here. Especially for those interested in switching or vapers who have not been vaping for that long, it is particularly worth taking a look at the traditional protective functions of an e-cigarette at this point!
The draw time limit, sometimes also referred to as “10 second protection” in older publications, prevents the mod from releasing voltage for longer than a defined time when the fire button is pressed once. Otherwise, it could happen that a device evaporates liquid if you forget to switch it off before putting it in your pocket, especially during transport or if the e-cigarette is accidentally left lying around. The result would be overheating of the circuit board and other components, as well as damage to the coil and the cotton. The draw time limit is also intended to prevent too much vapor being inhaled at once when in doubt. With classic e-cigarettes, the maximum draw time is usually set to 10 seconds. With some devices, it can be extended to up to 15 seconds via menu navigation. With some smaller pod systems in particular, the limit can also be around the 7 or 8 second mark.
If the residual charge voltage of a battery falls below a certain limit, the so-called end-of-discharge voltage, a deep discharge occurs. In the best case, this can only lead to a minimization of the capacity of the battery, under certain circumstances it can also lead to a defect in the battery cell. The protection against deep discharge in e-cigarettes prevents this in that the battery - here too, it does not matter whether it is permanently installed or external - no longer emits any voltage before the end-of-discharge voltage is reached. In devices with an integrated display, this is usually indicated by a message on the screen, in simpler models by a flashing or colored LED.
If the mainboard or the PCBA (Printed Circuit Board Assembly) on which the chip is implemented gets too hot, the mod only releases voltage again when the temperature of the PCBA is below a critical value. This can be due to high outside temperatures or a combination of the outside temperature and the working capacity of the device. If the device were used with an overheated mainboard, electrical components could be permanently damaged.
Electric current always chooses the path of least resistance. As a rule, the direction of the current flow within a closed circuit is specified. Damage, for example to the insulators of electrical wires, can cause current to jump from one pole to the other without encountering any resistance. This is commonly referred to as a short circuit. Very high currents can flow through the resulting resistance-free connection, which can lead to overheating of components and further damage to the insulation. The short-circuit protection ensures that the line is interrupted in the event of a short-circuit.
Just like deep discharge, overcharging a battery could damage or even destroy it. If lithium-ion batteries are overcharged, the layered structure of the metal oxides collapses. This process is highly exothermic, large amounts of energy are released and elemental oxygen is formed. Due to the high temperatures, the organic electrolytic liquid can evaporate, with the formation of easily combustible gases. A charging control such as overvoltage protection prevents this by automatically ending the charging process as soon as the battery is fully charged.
Like mods with an integrated battery, battery carriers are designed to work with coils in a specific resistance range (e.g. 0.05 to 3.0 ohms). If the resistance selected is too low, a short circuit could occur due to skipping currents. If, on the other hand, a coil with a very high resistance is fired with too little voltage, the liquid cannot evaporate completely. Regulated mods that work with unsuitable resistance protection measure the resistance on the atomizer and do not emit any voltage if the resistance is outside the specified range. A corresponding error message is usually output here as well.
If you use a battery carrier that requires two or more battery cells to operate, each battery should have had the same number of charging cycles if the batteries are connected in parallel. It is therefore advisable to only ever use a combination of battery cells with one another (this is referred to as “married batteries”). Batteries are subject to natural wear and tear, the charging voltage drops with each charging and discharging process. If batteries with different charging voltages were used, voltage could transfer from the more highly charged to the less charged battery when connected in parallel. It is said that one battery feeds the other. The currents flowing during this process can be significantly higher than the amperage with which the respective battery can be charged, which could lead to outgassing of the battery cell. Mods with Imbalanced Batteries Protection do not emit any voltage if the voltage difference between two battery cells is too large.
In the interplay between technical development and different user requirements, the e-cigarette is continuously evolving. Good to know that the important issue of safety always plays a central role in new innovations!