Vaping 101: Battery Safety and Ohm’s Law

One of the major problems with vaping these days is battery safety. There are many of us that know how to properly use our 18650 batteries with our various types of mods, but there are a few vapers out there that do not practice battery safety. Usually it is not their fault, it is the fault of the vape shop that did not inform their customers about proper battery safety. Unfortunately these few vapers are usually broadcast-ed throughout the media now and then.

New studies are continuously showing positive facts about vaping, so the media is always trying to find new ways to show a negative view on our industry. One of the only negative views being shown lately is of electronic cigarette batteries blowing up.

While there have been an extremely small number of battery explosions compared to the number of people that actually vape, every time one does happen, the stories spread like wild fire throughout social media. When non-vapers see these stories and videos, they automatically assume that most electronic cigarette batteries are an accident waiting to happen.

vaping battery safety aspen valley vapes

This is something that can be prevented though! If you are going to go out of your way to build your own cloud chasing coils, and try to be that dare devil that vapes at super low ohm’s, please… PLEASE… make sure you are following proper battery safety! Even if you aren’t one of these dare devils, you still need to properly maintain your batteries, because vaping at low ohm’s isn’t the only thing causing these explosions.

If you are curious to know what level wattage or voltage is safe to vape check out our article: What Voltage/Wattage Setting Should I Use For My Electronic Cigarette?

This article is going to focus strictly on battery safety.

Lets Begin With Battery Safety 101

Battery Case Aspen Valley Vapes

Never let your batteries touch each other or any other metallic items!

Most of us have seen the recent incident of the guys battery that exploded in his pocket. This was due to his batteries not safely being carried around. You can purchase battery covers/holders to keep your batteries from touching, and away from other metallic items. NEVER put your battery in your pants pocket/purse/backpack/etc. without first placing it inside of a battery case or battery cover.

Letting your batteries touch each other or any other metallic item is a great way to have your batteries fail and it has the potential cause serious harm.

Never put your batteries in backwards

Positive Negative Batteries Aspen Valley Vapes

Make sure to pay attention when placing your batteries into your mod. If you place your batteries in backwards you risk having them vent, which could lead to some serious harm. Some mods may have reverse polarity protection, but not all do! Even if your mod does have reverse polarity protection, please don’t insert your batteries incorrectly.

Never let your batteries short circuit

Short circuiting occurs when the positive and negative terminals of a battery are connected with a low resistance wire. The low resistance causes the battery to deliver a large amount of energy in a short time, that exceeds the battery’s upper amp limit.

When using a regulated box mod with a sub-ohm tank that has pre-made coils, this is something you don’t usually have to worry about. For those that like to go the unregulated route, and build their own coils, you need to make sure that you keep the resistance under the upper amp limit of the battery that you’re using.


Never overcharge your batteries

When charging your batteries, always make sure you have an eye on them. Never leave your batteries unsupervised, make sure to check every 15-30 minutes to see if they are fully charged. Once you see a battery has been fully charged, take that battery off the charger. Leaving batteries in a charger too long can cause them to overcharge, which has a good probability of causing battery failure. Charging batteries over 4.25v can shorten the life-cycle and going over 4.5v can cause it to explode.

Never over-discharge your batteries or leave your batteries at a resting voltage below 3.6v

over-discharged battery avv

Leaving your batteries below 3.6v will cause irreversible damage. Leaving your batteries in a discharged state will create a loss in capacity and cycles.

You can find the exact voltage of a battery with a multimeter. If you are one that builds your own coils you should make sure that a multimeter is a MUST HAVE item in your coil building fleet. A multimeter allows you to test your coils and your batteries, making sure you know what level you are at for each.

Never expose a battery to fire or high temperatures

There are chemicals in a battery that should never be exposed to fire and/or high temperatures. Dangerous fumes will be released if you try to burn a battery, which will most likely result in an explosion. That means that you should also never leave your battery somewhere that is constantly exposed to high temperatures, such as your car.

If you are looking to dispose your batteries, make sure to take your batteries to a battery recycling center.

You can find your local battery recycling center by clicking here.

Never use batteries that are dented

If your battery is dented DO NOT USE IT! There is most likely internal damage to this battery which can cause a short.

dented 18650 battery aspen valley vapes

ALWAYS use “Married” batteries

When using electronic cigarettes that take two or three 18650 batteries, always make sure that the batteries stay together their whole life. You should always make sure these two batteries are discharged and recharged together at all times.

If you use an old and new battery together, there’s a possibility that the old battery will discharge below the normal 3.2v, which will damage the battery and possibly your device.

When using batteries that are married, you will reliably get the same number of charges from both. This allows you to know when they are both at the end of their life cycle.

Always pay attention to the temperature

Keep your batteries away from extreme temperatures, both heat and cold will put stress on your batteries. Make sure to always use and charge your batteries at room temperature. If your batteries have been exposed to extreme temperatures, allow them to return back to room temperature before using or charging again.

If you are wanting to store your batteries for a long period of time (months or years), make sure to discharge them to 3.8v and store them in a cool dry place. Refrigerators are great for storing batteries, but you need to make sure that you are protecting your batteries from moisture.

Get rid of batteries after 6 months of use

We recommend that you properly dispose of old batteries after a good 6 months of use. If you use the batteries often, you will usually find around this time that the batteries will no longer charge to a full 4.2v. You can check to see how far your batteries charge up to with a multimeter, which we recommended earlier. If you find that you are falling short of 4.0v when charging your batteries, make sure to properly dispose of these batteries, and purchase a new set. Once again you can find a local recycling center with the link found above.

recycle 18650 batteries aspen valley vapes

Advanced Battery Safety and Ohm’s Law For Vaping

How to determine your maximum discharge rate

When talking about vaping and battery safety, the most important specification to pay attention to is the Maximum Continuous Discharge Rate. Each battery has a different rate, so pay close attention to the specs of each one.

IMR18650 – 1600

Nominal Voltage: 3.7v

Capacity: 1600mAh

Lowest Discharge Voltage: 2.50v

Maximum Continuous Discharge Rate: 15C

Operating Discharge Temperature: -10C ~ 60C

Each battery will have a number or letter. The letter will either be an “A” for Amps or “C” for Celsius. By looking at the battery broken down above you can see that the maximum continuous discharge rate of this specific battery is 15C. This means the battery is rated for 15 times the capacity of the battery measured in amps. This specific battery has a capacity of 1600mAh, which equals to 1.6Ah, so your max continuous discharge rate is 15 X 1.6 which equals 24A.

Make sure to determine your maximum continuous discharge rate in Amps to help keep your math consistent. Many of the newer batteries will usually already have this specification in Amps, but if you were to have one in Celcius, above is the correct equation to convert to Amps.

Ohm’s Law and Vaping

First off lets define Ohm’s Law:

Ohm’s Law deals with the relationship between voltage and current in an ideal conductor (wire). This relationship states that: The potiential difference (voltage) across an ideal conductor (wire) is proportional to the current through it. The constant of proportionality is called the “resistance”, R.

How to find the discharge rate for your newly built coil

To make sure that your coil doesn’t short your battery you will want to follow this simple equation:

Battery Volts / Resistance (ohms) of your coil = your discharge rate.

If your discharge rate is less than the maximum discharge rate of your battery then you are good to go!  BUT if your discharge rate is MORE than the maximum discharge rate of your battery, you need to go back to your coil building desk and build a higher resistance coil. If you risk using the coil that has a higher discharge rate than what your battery can handle, you risk shorting the battery and harming yourself.

If we use the battery we mentioned above in this equation this is how it would work. If you use the IMR18650  – 1600 battery, and at a full charge your multimeter shows that the battery is at 4v, you need to divide that voltage by the ohms of the coil you built. This is how the equation would look:

4v (battery voltage at full charge) / 0.2Ohm (resistance of your current coil) = 20A (your discharge rate).

As you can see with this example, your coil is 4amps under the maximum discharge rate of your battery. In this case you have a coil that is safe to vape! If you are using a different type of battery that has say a 16 amp maximum discharge rate, you would risk battery failure, which once again can lead to serious harm.

Always remember as well that the resistance in coils can vary by +/- .2ohms. This means that a coil that shows .4ohm can actually be a .2ohm coil. Always take this in to fact when building coils to practice battery safety!

You can use this Ohm’s calculator to help you build an accurate coil.


Many of us practice proper battery safety, but unfortunately not ALL of us do. This isn’t always due to negligence, it may be just be because that the vape shop did not properly educate the vaper. When there is a mishap with electronic cigarettes in the media it makes this industry look very unstable. Lets make sure we as fellow vapers educate those that may not know battery safety, so that we can keep this industry running safely.

Enjoy this article? Let us know any comments you have on battery safety! Feel we missed something? Let us know, we always love to hear from our fellow vapers.

5 thoughts on “Vaping 101: Battery Safety and Ohm’s Law

  1. Brian Hayes says:

    Kudos for posting. Vendors should post regular safety guides and reminders.

    Is there a definitive statement on when to stop using a vapor battery? Perhaps for smaller, cheaper e-cigs a few years ago, but I’m not so sure about disposal at 6 months… a manufacturer warranty is longer. Not an expert, shouldn’t list counter points I don’t fully understand, just don’t recall seeing this statement before, not in vapor forum and not in flashlight sector, not on store sites usually worried about liability. Looking for something that backs this up.

    • Aspen Valley Vapes says:


      This is just a recommendation. A lot of vapers on reddit will usually recommend this as well. You should always check your multimeter and see if your batteries are still fully charging to 4.2v. If they drop below 4.0v that is when we recommend to dispose of them.

      Hopefully this answers your question!

  2. Pingback: 12 Vaping Myths Debunked | Aspen Valley Vapes

  3. Shawn Troxel says:

    I am so glad to have found this explained so simply. I build extremely low and it has been a concern since have been debating getting an unregulated mod recently. Now I can make the transition without going in blind. Thank you so much for explaining it .

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