Are Regulated Mods As Safe As We Think?

Regulated mods are designed to be “safe," but there are things you should know to make them even safer.


How many times have you seen headlines like, “Man’s face blown up after e-cigarette explodes while he’s smoking it”? It seems like there’s a vaping explosion story every week, with a suitably over-the-top description 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 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 differences between regulated and unregulated mods. The basics are pretty 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 (or directly adjust the voltage), or 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 always 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 list of catastrophic 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. The mod is firing itself.

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 the current you’re trying to draw. There is a useful tool at Steam-Engine to work this 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 the danger 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 very quickly.

Although there are many things that contribute to the risk of a thermal event (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. Unfortunately, these are the batteries that didn’t meet quality standards during testing, so rather than selling them under their own names, the manufacturers sell them to companies like Efest, who sometimes imply that they will 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 for an hour) 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 thermal runaway. 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 be dangerous.

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 vape – or any device with a 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 cutoff for accidental firing could fail to kick in and allow a device to fire until 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 apply to all lithium battery-based devices. Vaping mods 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 or clone you picked up for $15 from a shady website
  • Do choose capable batteries. Make sure you choose batteries with a high enough “continuous current (or amperage) rating” for the amount you’ll be drawing. Use Steam Engine’s tool to work out how much current you need to draw and what kind of batteries you’ll need
  • Do switch off or lock your device when you carry it in bag or pocket. 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 and rubber sleeves 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. Replacement wraps cost almost nothing and are easy to apply
  • 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 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.