Are regulated mods as safe as we think?

Regulated mods are designed to be “safe”, but there are things to know to make them more safe.

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How many times have you seen headlines like this? “Man’s face blown up after e-cigarette explodes while he’s smoking it!” It feels like there’s one every week. With a suitably over-the-top description (because his face didn’t really “blow up,” did it?) and some gruesome pictures, it’s an easy way to earn some clicks and tap into the controversy surrounding vaping.

The problem is that these stories scare people, including smokers who might be considering switching to vaping – and parents who, let’s face it, just worry about everything.

Vapers don’t want rare accidents to discourage someone from quitting, and we’re always quick to offer explanations for what went wrong. In the case cited above, maybe the vaper was using a mechanical mod with a self-made coil built at an unsafe resistance. Mechanical mods don’t have the safety features that you’ll find on regulated devices, and if you don’t know what you’re doing, they can be dangerous.

“If you use a regulated device and a good battery,” we say, “your mod won’t explode.” We’ll criticize shoddy manufacturing practices and re-wrapped batteries, but ultimately most vapers argue that well-made mods are as safe as your cell phone or laptop.

But are we right? Can you really rest easy just because you have a regulated mod and not a mechanical one? Are regulated mods as safe as we think?

With and without regulation


Before getting into the safety of regulated mods, it’s important to understand the difference between a mods with and without regulation. We have a more detailed explanation here, but the basics are simple.

Mechanical devices just send the unadjusted (“raw”) battery voltage to your atomizer and don’t have a minimum allowable resistance or any other safety features. If you attach a really low ohm coil to a mechanical mod without a suitable battery, nothing will stop the flow of power that could stress the battery to the point of failure.

Regulated mods generally allow you to adjust the wattage (and/or directly adjust the voltage) or just operate at a fixed voltage. They also have safety features, including minimum resistances, maximum currents, cut-offs if you’re continuously firing for too long, high internal temperature cut-offs and more. Modern regulated devices do everything a mechanical mod can but take safety into account for you, rather than expecting you to do it on your own.

This is why they’re generally seen as the safer choice for the average user. Although a mechanical mod probably isn’t dangerous if you know what you’re doing, there is substantially more risk if you don’t know what you’re doing.

Regulated mods can fail too

However, as the recent furor over the Wismec Exo Skeleton shows, regulated mods aren’t guaranteed to be safe. Users have reported the mods exploding and the interior basically melting, and although they haven’t been recalled, vapers are understandably concerned. Other cases such as problems with the iCare and more famously, the 50W iStick, remind us that just because it’s a VV/VW mod, it’s not necessarily completely safe.

The huge list of catastrohic failures at eCig One shows that while most cases are related to unsafe practices when carrying batteries or mechanical devices, regulated mods are involved in some failures.

Why regulated mods can have problems


So what’s happening? Why don’t all the safety features prevent any vapers from having issues with their regulated mods?

There are many potential explanations, but here are some of the most important ones:

Problems with “autofiring”

For the famous iStick 50W case and more recently, the iCare, as well as many other vape pens and mods, a big problem is “autofiring”. This is when the battery fires when you don’t intend it to, like when there is nothing pressing the fire button down – hence “autofiriing”.

This can cause many kinds of problems, from completely burning through your juice and setting fire to your wick to dangerously stressing your battery. If a mod autofires – even just briefly and then seems to stop – it’s defective and needs to be retired, because if it happens when you’re not there, you could wind up with a serious fire.

Using incorrect or inappropriate batteries

For regulated mods that don’t have a built-in battery, another potential issue is using batteries that can’t cope with how much current you’re trying to draw. There is a useful tool at Steam-Engine to work this all out, but the short version is that batteries can only safely provide so much current. If you draw more current than the maximum for that model, you risk pushing it to breaking point.

Most of the potential problems posed by batteries ultimately come down to heat. When the battery gets too warm inside, this causes damage, which means the battery gets even hotter, which causes more damage and so on. This is called “thermal runaway,” and it can be an issue for all lithium-based batteries. They will generally vent hot gas rather than exploding, but if your mod doesn’t have sufficient vent holes for the gas to escape through, this can become dangerous as pressure builds up inside.

Although there are many things that contribute to the risk of a thermal issue (including the age of the battery, for instance), asking for more current than the battery can safely supply generates enough heat to start to damage the battery’s interior.

Regulated mods try to reduce this risk by including a maximum current limit in the safety features, but if your battery can’t safely supply that amount, you could still be at risk. Choosing a battery with a reasonably high current rating is the safest approach.

It’s better to stick to the big manufacturers because many other batteries are “rewrapped” versions of inferior cells made by those same companies. Unfortunately, these are the batteries that didn’t meet their quality standards so rather than selling them under their own names, they sold them to companies like Efest, who often imply that they can supply more current than they really can.

Exposing batteries to high temperatures


Temperature is the enemy when it comes to batteries, so leaving your mod in direct sunlight all day (or even just sitting on your car’s dashboard) could cause problems. Generally, you should avoid having batteries in extreme temperatures (hot or cold), but heat is a bigger issue. This is thankfully easy to avoid, but it’s something to keep in mind.

Other battery issues

There are other potential problems relating to batteries too. If the wrap on the outside – especially near the terminals – is pulled away, nicked or scratched off, this can cause shorts and other issues. If anything connects the terminals of two or more batteries in a multi-battery mod, you could end up with a dangerous short that could lead to a thermal runway. Even contact from a metallic battery door of a poorly-designed device could lead to problems.

Finally, more obvious damage to the battery – for example, a dent from being dropped – could mean there is internal damage too, which could cause problems.

Faulty charging circuits


Even simpler regulated devices, like fixed-voltage eGo-style vape pens, can explode in some cases. This is almost always related to charging, and could be caused by issues with the charging circuit on poorly-made devices. For example, the charging circuitry could draw too much current from the charger or not stop drawing current when it’s fully-charged. The problem here is hard to identify in advance, so the best advice is to stick to reputable companies that receive positive reviews from vapers and don’t just choose the cheapest device you can find.

Poor charging practices

Problems with charging are often made worse because the owner didn’t follow good charging practices. You should never charge your e-cig – or any lithium battery – overnight. In fact, you shouldn’t leave it charging unattended at all, and you should remove the battery after it’s finished charging. It’s also a good idea to charge your e-cig away from flammable materials, just in case there is a problem.

Could the protections in regulated mods fail?


Although there are no cases related to this that we’re aware of, it’s entirely possible that some regulated mods have issues with the safety features. Just like charging circuits may not always work like they should, there is no guarantee that all of the safety features on a mod will work as intended. For example, a faulty resistance reader could lead you to use a coil with dangerously low resistance, or the 10-second cut-off for accidental firing could fail to kick in and allow a device to fire till the battery overheats.

The lack of documented cases like this with regulated mods suggests that it’s probably extremely uncommon.

Should vapers be worried?


eCig One’s impressive work in documenting e-cigarette catastrophes shows that battery venting and failures are really quite rare. Their first documented one was in 2009, and in the eight years since then there have only been 243 confirmed incidents worldwide. This is about 30 a year. It might sound like a lot, but remember that there are millions of vapers around the world. The numbers we’re talking about are tiny when put into context.

The truth is that a regulated mod made by a reputable manufacturer and using a suitable, well-made battery is no more dangerous than your mobile phone or laptop. The risks discussed here aren’t just the risks of “e-cigarette batteries”; they’re the risks of all lithium-based batteries. Vaping devices may have a few additional issues – for example, requiring users to know which batteries can be safely used – but on the whole most vapers have little to worry about.

You shouldn’t be complacent, but as long as you learn the basics of battery safety and don’t assume you’re completely and totally safe just because you have a regulated mod, there is no need to panic. Your box mod is not a time bomb.

Vape safely with regulated mods


If you have a regulated mod and you want to stay as safe as possible, there are many simple steps you can take to substantially reduce the risk:

  • Don’t buy cheap. Buy your mods from a manufacturer with a good reputation. An Innokin device is much less likely to have problems than a off-brand mod you picked up for $15 from a shady website
  • Do choose capable batteries. Make sure you choose batteries with a high enough “continuous current rating” for the amount you’ll be drawing. Use Steam Engine’s tool to work out how much current you’ll be drawing and what kind of batteries you’ll need
  • Do switch off or lock your device when you carry it. Auto-firing can be a defect in the device, but it’s often down to user error. Always lock or switch your mod off before putting it in your pocket
  • Don’t carry loose batteries around with you. Loose batteries can short out on metal objects like keys or coins in your pocket. A worrying amount of e-cigarette explosions happen this way, so don’t take the risk. Plastic battery holders are widely available and cheap – don’t carry loose batteries around without one
  • Don’t leave your mod in direct sunlight. This is simple – your batteries could get too hot if they’re left in direct sunlight or near other sources of heat
  • Do regularly check your battery wraps for damage. You might not think your battery’s wraps are damaged, but it’s worth checking them regularly just in case
  • Don’t drop your mod. Accidents will happen, but remember that every time you drop your mod you risk damaging your battery (even if it’s an internal one). Be careful with your mod and inspect it carefully for damage if you do drop it

Conclusion: Don’t Panic!


Regulated mods shouldn’t give vapers much to ever worry about. As long as you know basic safety rules for vaping, you’re no more likely to have issues with your mod than you are with your cell phone or any other electronic device in your home. You shouldn’t be complacent, but you can also rest easy in the knowledge that your mod probably isn’t a hysterical tabloid headline waiting to happen.

Lee Johnson

Lee is a writer and vaper from the UK. He quit smoking (without intending to) in 2012, and now spends his time writing about the conflict between science and ideology in the vaping debate. He’s a firm believer that smokers deserve the facts on tobacco harm reduction without the fearmongering. He probably drinks too much tea.

  • Jeffery Jelinski

    Regulated mods are a lot safer but not foolproof. You still need relatively safe batteries for one though you can get away with a little less.

    Figuring your amp draw safely for regulated is easy. Watts you run at divided by lowest battery volts the mod will fire at for a worst case scenario. Usually 3.2v for the large majority of mods. Then divide that amp figure by your number of batteries or multiply the voltage in the equation to 6.4v or 9.6v for double or triple battery mods. Series or parallel will give the same overall result.

    To make it easy. My Fuchai 213 stops firing at 3.2v on the batteries, a pretty safe and common number. It’s a dual battery mod so my lowest combined voltage will be 6.4v. The highest I will ever go with the setup I use is about 90w so 100W gives a very healthy margin of safety. I like to overestimate the wattage a bit so as to leave a margin for safety and overhead for the efficiency of the mod.

    100W / 6.4v = 15.625amps per battery
    100W / 3.2v = 31.25amps total divided by 2 batteries = 15.625amps per battery

    So at 100W on my regulated mod I can get away with 15A rated batteries pretty safely even in a worst case scenario. I choose to use Samsung 30Qs which are rated at 15A but in real life perform well as a 20A battery. I also never run over about 90W which reduces the load even more. This means even though I’m not running a top-rated 2500mAh 25A battery like a Samsung 25R or Sony VTC5, I still have plenty of margin for safety and performance. The 3000mAh 15/20A rated Samsung 30Qs work great for my needs and offer increased battery life over the higher rated batteries.

    If I were running my mod at its max of 200+W I would definitely want a 25-30A rated battery. But because I run conservative wattages, I can get away with a lot less and get a higher capacity battery. If you are less experienced, you should still go for the best battery possible as a matter of safety. If you’re more experienced, there’s quite a bit of wiggle room.

    • Lee Johnson

      Great advice Jeffery! Thanks very much! Like many others I used to calculate this incorrectly using the standard form of Ohm’s law. Luckily I tend to vape at lower wattages too so I always had a huge safety margin

      • Jeffery Jelinski

        Thanks for the compliment! I’m not a very advanced vaper so these basic rules helped me a lot when I was starting out.

  • Andrew Lane

    Another way to stay safe is to use a temperature controlled mod rather then a VV/VW mod. I have my Joytech eVic Primo Mini set to 225C @ 50W max power using a 0.2 ohm Ni200 coil. It pulls up to 50W for less then then a second to heat the coil up to temperature but then drops down to the mid 20Ws or lower to maintain the temperature. My purple Efest batteries with a stated rating of 20A continuous and 35A pulse can easily handle this without getting too hot to handle.