Vape Battery Safety: Will You Marry Me?

Batteries, batteries, batteries: so many to choose from! How do you know which one is right for you? Well, call me the matchmaker, because I’m here to help you decide! Before you can find your mate, you’ll need to learn a little about what makes a vape battery tick.


First of all, how does a vape battery work? Well, without getting too complicated, the battery is made up of stacked “cells.” Each cell has a negative terminal and a positive terminal immersed in an electrolyte solution. When you put your battery in a circuit, an interaction between chemicals occurs. This causes positively and negatively-charged ions in an electrolyte solution to want to move to a terminal on each side of the cell known as an “anode” (negative terminal) and a “cathode” (positive terminal). This movement of ions allows energy to flow to an external device, powering it. When you charge a battery, you reverse the chemical reaction used to discharge the cell, literally resetting the ions back to the way they were. Ultimately, a little is lost in the process of resetting each time you do it. Eventually, the chemical reaction will no longer occur. This is why batteries have to be replaced and cannot be recharged forever.

Now, I want to quickly talk about differences in quality. You need to understand that not all companies are equal. There are battery makers that are notorious for mislabeling their batteries or claiming they can handle higher loads than they really can. Stay away from any brand with “fire” in the name, as a general rule. I suggest using one of the top 4 brands; Hohm Life, Samsung, LG or Sony. And make sure you’re getting them from a reputable company because just as they will misstate the ratings, they will sometimes outright claim to be a Sony but are actually knock-offs or counterfeits.


So, there’s a lot of different numbers on a vape battery. What do they all mean? Let’s start with the number that determines the physical size of the battery. The number is 5 digits that together, spell out the dimensions. The first 2 are the battery’s diameter (in mm) and the last 3 are the battery’s height (in 10ths of a mm). So using an 18650 as an example: 18mm in diameter, 650 tenths of a mm (ie 65mm) in height. This is the first limitation to consider when selecting a battery for your device. In many ways, this will ultimately determine the capacity the battery can store. The chemistry inside is also a huge factor as two 18650 batteries can (and most likely will) have different internal designs but generally, the bigger the battery, the more cells you can fit inside. 18650 is definitely the most popular, but other sizes exist for smaller or larger devices, so make sure your battery compartment will hold the size you want it to (measure it if you’re unsure).

Next, there is a letter code that represents the chemistry interacting inside the battery. The ones we use in e-cigs are Lithium Ion Batteries which are inherently safe. The most common ones you’ll see (and want to use) are; IMR- Lithium Manganese and INR- Lithium Nickel. The nickel/manganese is what the cathode is made out of in these examples using these different materials yields different results. For example INR can typically have a higher capacity, but suffers from not being able to handle as high of a load as IMR.


To talk more about vape batteries, we’ll need to define a couple words. Electricity is a hard thing to describe, so most people find it helpful to compare it to something we can see. Imagine a series of pipes connected in a loop with water running through them while we define these words.


 The potential of electrical energy if it were allowed to flow fully. Using our analogy, this would be the water pressure.

(I)Current T

The flow rate of the energy and is measured in Amperes. Using the same example, amps would be the rate the water is flowing.


 A material’s opposition to electrical energy, measured in ohms. Again, using our example, this would be the the size of the pipe.

Ohm’s Law- I=V/R

A system used to calculate the relationship between these 3 things. Ohm’s law states that it takes 1 volt to push 1 amp through 1 ohm of resistance. To relate this to our example, let’s say it takes 30 psi (pounds per square inch) of pressure to push 1.3 gallons per minute through a pipe that’s .31” in diameter (this is true by the way). Changing any of these 3 things will affect one of the others. If you use more pressure on the same pipe, you’re going to get more gallons per minute. If you want more gallons per minute but keep the pressure the same, you’re going to need a bigger pipe.


This DOES NOT stand for Milliamps per hour. This is one of the most common errors I see. It stands for Milliamp Hours. For an example let’s say a battery is 2000mAh. This means that if the battery were in a circuit that only drew 1 milliamp, it could power it for 2000 hours. Unfortunately for us, our ecigs usually draw more than one milliamp. My setup is drawing 7.4 amps. Which means that it can run for 16 minutes of vape time total. Since I take about 3 second puffs, that’s 324 draws until it is dead. While we’d all love to have a 10,000mAh battery, usually a higher mAh means sacrificing some of your amp limit.


3.7V is the standard output for a fully charged battery. This is it’s “under load” voltage. As you use the battery up it loses volts. Letting it fall below a certain point causes internal damage to the battery. The most popular regulated devices don’t let this happen. They will stop allowing you to fire at around 3.2v. Keep in mind that if we’re talking about mechanical mods, this is going to directly affect the performance of the vape. Using our example, you’re still using the same pipe size (resistance), but you’ve decreased the pressure (volts) so you’re going to get less gallons per minute (amps). With regulated mods, your performance will not be affected until the battery dies, but there are different things going on inside. When you tell the device you want a certain end result (watts) it takes what it is given and amplifies it to reach that result. So, as your battery dies, it draws MORE amps from your battery to make up for the loss in voltage according to ohm’s law.

Amp Rating

There are two ratings, and you need to know the difference between. Pulse rating and continuous rating. Pulse rating is the amps you can safely draw if you were only doing it for just a moment, like fractions of a second. Continuous rating is the amps you can safely draw indefinitely until the battery runs out. Both of the ratings are essentially based on how hot the battery will become and whether or not the internals would fail at that temperature, causing them to vent. Generally, you don’t want your batteries to be hot or even warm. In vaping, we use the continuous rating for 2 reasons. One is that three seconds (an average draw) is certainly longer than what “pulse” covers. The second is that if your mod or the switch on it should somehow fail and continuously fire, you want to be within your continuous limit. Since my Hohm Life 18650 2500 mAh battery has a continuous rating of 20a, we will use it for examples from here on.

So, how do you calculate your amps and determine if you are being safe? Well, if you’re using a mechanical mod it’s easy-peasy, just use ohm’s law above. When you’re using a regulated mod, things get a bit tricky, but here’s the equation you will want to use: I=P/V where P is the maximum watts you want to get. Let’s say 40 watts. I=40w/V. Here’s the part where you need to pay attention: V is not a constant number. Your volts go down as the battery is depleted, so when you’re calculating this, you want to use the volts for an almost dead battery, (since that’s what it will eventually be) 3.2v for practical application, 2.5v if you want to be extra safe. So if I=40w/3.2 or I=12.5, my setup is well within the safe zone. What happens when your mod takes multiple batteries?


Multiple battery mods are configured in 1 of 2 ways. These are called series and parallel. A series connection will treat 2 batteries as 1. The voltage is doubled but the capacity and amp limit remain the same. A parallel connection will double the capacity and amp limit but still only deliver 3.7 volts on a full charge. They ultimately work to achieve the same end result, but they do it in different ways. Let’s look:

Series:     I=80w/6.4v (3.2v times 2)  I=12.5 Amps. You are within your amp limit.

Parallel:   I=80w/3.2v (V does not double in parallel) I=25 amps. Uh-oh! Are we over our limit? Nope, remember that in parallel the capacity and amp limit are doubled.


“Married” batteries means 2 batteries together for their whole life. They can go in different mods as long as they are never split up. They should be discharged and recharged at the same time, every time. If your mod is configured in series, then you should also rotate the position of the batteries each time. This is because the first battery in the series will take the brunt of the force so you want to alternate the duties of your batteries. If an old and a new vape battery are used together, it’s possible for the old one to be discharged below the normal 3.2v causing damage to the battery and maybe your device. You will also reliably get the same number of charges from both, and know when they are both at the end of their life using the married method.

I hope you enjoyed this article. Vape battery safety can be hard to understand and cumbersome to talk about, but it is by far one of the most important aspects of vaping. Please share this information with all of your closest friends and help spread awareness about battery safety. If you’re looking to pick up some new ones, I highly recommend these available on our website. Stay safe and happy vaping!

You may also like our article on environmentalism and vaping!

Tim Mechling

Tim is Mt Baker Vapor's resident creative weirdo. He writes, composes music, draws, designs, produces podcasts, investigates, and blows the trumpet for the Common Man.

  • John says:

    Some good info in this post.

  • Seth Carroll says:

    Even when having a better than basic knowledge of electric theory and the like; his article helps apply my knowledge better to the Vaping application.
    Very well written Tim!

  • Mitch Rubin says:

    What an amazing article! I am a sucker for battery knowledge and this just blew my mind! The pipes/water analogy helped paint such a clear picture in mind of what exactly is going on. Btw why does efest put the lulse rating and not max continuous discharge # on their wraps? Is this a sales ploy? Like if LG, Sony, Samsung puts the max continuous discharge # on the wrap and is so honest y does efest put 35A/38A/40A on theirs? I know ppl see that and think the amps on these are better than a 20A Samsung when reality they are the same or close to it. Unless otherwise explained to me this is y i choose not to use efests, cause of their trickiness and lack of true honesty. But with that being said you (Tim) are some1 i respect very highly in the vape community (and in many other aspects) so maybe u can convert me or at least “defend” those tricky ppl over at efest. Its so funny u posted this btw, cause like i said b4 im a sucker for battery knowledge and batteries (ever since i started needing batteries for vaping) and i watch youtube vids on batteries but this article really clears it all up! I was so happy to get the the end of the article and see TMECH as the author! That made my night. Anyways hipe to hear back from you. Ttyl

  • mitch rubin says:

    My buddy got the samsung 26f’s in the mail and it says 2600mah 2c. What the heck is 2c? He used them and they fire but it doesnt have an amp rating? Do u know the amps or what 2c means? Thanks guys!!

  • mitch rubin says:

    Aight sounds good Tmech. Ive seen “c” before after max continuous discharge but never bought them or knew any1 that did till now. He actually ordered something else but got the Samsung 26f’s with that 2C max continuous discharge so im eager to see what he says what it means, assuming he knows. Aight ttyl!

  • Marcel K says:

    The 2C is a rating like the Amp rating. Basically it is just another form of code for how much load the battery can supply safely. The number before the C (in this case 2) states, how many times the capacity a battery can supply load. In your case with a 2600mah 2c it is simply: 2 x 2600 = 5200 mAh or 5.2 Amps

    To get the C rating of the Efest Battery with 20A rating you just turn it around and divide Amp-Rating (20A) with Battery Capacity (2500mAh) and remember that 1A = 1000mA: 20’000 /2500 = 8; So the C Rating of the Efest is 8C

  • mitch rubin says:

    Wow! Dr. Marcel K, thank you! Professor Battery! So are the 5.2 amps enough? I know my LG HD2 batteries are 25A and they say dont go lower than 15-20a (i think) and my buddy is using these Samsung 26f’s (5.2a) in his Sigelei 150 with a .2ohm coil. Is he safe? Thanks Marcel!

  • mitch rubin says:

    Ok cool. Thanks John. He used them twice in his Sigelei 150 TC with a rda and it was firing but i was skeptical and scared right when i googled those batteries. Even more so i was scared when they came from china and they screwed up his order. He ordered 4 lg hg2’s and ended up getting the HG2’s and these pink Samsung 26f’s which i had never heard of. At first glance i thought they were Samsung 30Q’s (3000mah 15A) and was like ok thats pushing it but good enough then on closer inspection i saw they were in fact the 26F’s with a 2c max continuous discharge rating and told him not use them till I find out what they r and funny enough only a few days earlier this amazing article was posted on ur blog! So i had the opportunity to ask u guys on this post which is really cool how it all worked out. Anyways thanks for the info, John, Tmech, and Marcel and i cant remember who wrote this but thanks a lot!!!

  • Kurt M says:

    This is really helpful. I started vaping in July and really haven’t had the time to learn this stuff but knew I should. Thank you for the concise explanation!

  • Seth Carroll says:

    I had commented on this after it had been written. I just bought my first two sets of batteries and used your blog info to help my purchase. I have since borrowed my daughters finger nail polish to mark them for pairs, and also as A & B in each pair so I can change their placement in my new Sigel 150TC.
    Thanks again!

  • Mitch Rubin says:

    Like i said before, this article seriously needs to be published or put on all the forums or something. Its so educational. I’ve been trying to learn as much about batteries (specifically 18650s & vaping) and this article took my understanding to a whole new level. Everything from series to parallel to vv/vw regulated, unregulated, etc etc its all here. I have been rotating 2 sets of batteries (vtc4’s & a set of LG HD2’s) for about 9 weeks now & i think b/c i only own 4 batteries and rotate those 2 sets over & over again that I’m starting to see a drop off in life span. Bow I’m not sure, so maybe Tmech or Jordan, or some1 can help me here and tell me whats going on. Is this what happens to batteries on their way out? I do vape a lot and switch batteries once even twice a day and btw im using an ipv4s (which btw u can get right here at mtbakervapor.com) so should the batteries last 3/4/5 months? They charge pretty fast still. Maybe I’m just being paranoid and want to be on the up & up with my 18650s & have fresh new ones but i think they used to last longer in the ipv4s. I think i used to get more time out of them but kike i said i think they’re only 9 weeks old but i cant remember exactly. So maybe maybe theyre even older like 12 weeks perhaps. (Im not good with remembering time). Anyways im so stoked this article is getting some good attention. I keep sharing it and hoping new ppl come across it and the rest of the blog and website. Have a happy spooky halloween bwahahaha bwahahaha.

  • Mitch Rubin says:

    A year!? Ok im definitely just being paranoid with my batteries. Theyre good batteries too. What’s the mood like at the office? Spooky? Scary? Sugary (all the candy lol)? Boring? Tricky? Treaty? Or hiw bout just plain old Saturday’ee

  • wje says:

    Nicely written. Appropriate for the target audience. Good example of practical application of the math.

    I’ll second the idea that this deserves better visibility and more exposure to the community.

    One additional thought about the “wearing out” of the 18650s. I’ve read more than one article from people who are a LOT smarter than I when it comes to these batteries who say that halting the charging process early can greatly reduce the “internal stress” on the battery chemistry and significantly extend (double or more) the potential number of charge+discharge cycles in the battery’s useful lifespan.

    Charging to “only” 3.92 volts was reported to be the threshold for effectively maximizing the number of potential charge+discharge cycles.

    The trade-off is that they will require charging more frequently (i.e. their run-time will be reduced.)

    “There’s no such thing as a free lunch.”

    • Jordan Horrell says:

      Great tip! Of course, as you mention, there’s always a trade-off. I go through about 3 full charges a day, if I had to charge them any more than I do, I think I’d go crazy. If making your batteries last as long as possible is a main concern however, not a bad practice. Thank you for your kind feedback, I’m glad you enjoyed this blog!

  • spookiewon says:

    You’re not correct about battery size. The second TWO are the length in millimeters. The last digit is the shape of the cell. On the case of an 18650 the 0 is for round.

    So an 18650 is an 18mm x 65mm round battery.

  • spenser says:

    I had a question on how the batteries work with the new dna200 because i find it weird it uses 3 batteries and i bought mine a couple days ago and 2 are married from top to bottom the back 2 sit – to + and the 3rd sits + to –

    • Isaiah Davey says:

      That is a great question! I will talk to Jordan and try and get more information about “Marrying 3 batteries”! We will try and get a blog out for you 🙂 Great idea!

  • David says:

    You explicitly stated to stay away from companies with fire in the name and then recommended efest. Efest has a picture of fire right on the battery and there pushing low amp batteries now.

  • Katherina Vasiliou says:

    I bought a Kanger Tech Kbox Nano kit 60 watts . I also purchased A set of EFEST MNKE 20A 18650 LI-MN 1500. Can I use one of these batteries in my device?

  • Steve says:

    I just bought the rx200 and I have to get three 18650 batteries. This article has helped me so much in understanding the concept. But my question is what batteries should I get? I got the MXJO 3000maH 3.7V 35A batteries for my KangerTech Dripbox, but I dont think I did it right.. so please recommend the best ones for me..thanks. also is MXJO a brand you recommend?

  • Mitch Rubin says:

    Why do think you didn’t do it right? The MXJO 3000Mah 35A are fine according to Mooch315. Married batteries are married to themselves not to a mod. You can use the same batteries in different mods. With that being said the LG HG2’s on MBV’s site are the best batteries you can get and i would highly recommend them. Also i dont know if you have a charger but if you don’t i suggest you get one. Its always better to charge your batteries with a charger rather than usb via your mod. The Nitecore D4 is great, especially for someone using a RX200 bc theres 3 batteries. Hope this helps. P.S. If your ever unsure about a particular battery check out Mooch315, he is the battery master.

  • Richard C says:

    Is it alright to charge married batteries one at a time i.e. in a charger with only one bay.

  • Jones says:

    Hey I know this is a old post but I left me with a question. I’ve been using my 2 LG hg2 batteries back and forth in a istick 60w tc and am going to go to a dual 18650 mod. I guess I should not use these batteries in my new mod?

    • Corey G says:

      We recommend that with the purchase of a new dual mod, it is best to purchase two new batteries and keep them “Married”. This is the safest solution!

  • Sergio says:

    Hi dude
    Quick question, setup is mech mod with 0.17 ohm atomizer resistance and LG HE4 battery. According to steam-engine for continues drain we will have -24% headroom for 20A amp limit. But puff’s are happening around 3 seconds.
    Is this battery still safe to vape on it in mechanical mod with such pulse discharge?

    • Corey Gefroh says:

      Honestly, I am not 100% sure and would hate to tell you this is a safe setup when it is not. I would only use the recommended battery that your mech mod calls for. When it comes to battery safety. Can never be too safe. Wish I could offer more advice!

      • Sergio says:

        Dear Corey

        I know I should use something like Sony VTC5 with 30A limit, but as far as I know 30A is continuous so like HE4 20A. But we are using pulse for around 3 sec. That made me wired if still HE4 could be used or not.

  • Myrany says:

    I am just now using my first mod that takes 2 batteries (in series I believe Smok Alien 220). I bought a pair of brand new batteries, am keeping them together for use and charging, and rotating their position in the mod at every charging. From the start there was ever so slight a difference in the max charge of each of the 2 batteries (like .1 volts). Is this something to be concerned about?

    • Corey Gefroh says:

      I wouldn’t be concerned. Batteries very a bit but as long as there isn’t a drastic difference you should be fine.

  • Tristian Croucher says:

    if a mod uses more than two batteries like a quad parallel box would i need to keep all 4 married

  • Bryan Boswell says:

    Hi, I just purchased the smok gx350 kit with the tfv8 also the smok tfv12 separately. Would the LG hg2 3000mah 20a work for this mod? Or would I need some batteries a bit stronger?

    • Corey Gefroh says:

      Those should be fine. I would suggest using 4 new ones and start them together and keep them “married” If you use some old and some new, you may run into complications. You want an even discharge. If you need new batteries try the new HohmTech Hohm Life 18650 3077mAh Battery! Find it here: Battery

      Hope this helps!

  • Bryan Boswell says:

    Hi, thanks for the reply. I’m definitely going to use 4 new batteries and keep them together. Will the 4 hg2’s produce enough power to get to 350 watts?

  • >