Last year we discussed batteries - what they are, how they work, and how to not blow your peripheral limbs off with them. Based on recent news reports, it would seem some people didn't pay enough attention to item number three.

So I think it's appropriate we go over this again, paying particular attention to Lithium Ion batteries and their peculiarities, and how you can avoid ending having to learn how to tie your shoes one-handed.

Lithium-ion batteries

Lithium is the third element in the periodic table. It is a metal, is very small as far as atoms go, and is highly reactive. It is also fantastic for making batteries because of its light weight and ability to store large amounts of energy.

Lithium-ion batteries work by the exchange of electrons. When you charge a lithium-ion battery, an extra electron is forced into orbit around the atomic nucleus, creating an atom of ionised lithium. Then, when you connect your battery to something that draws electricity, the electrons break free of the lithium atom and flow into your device.

When lithium-ion batteries turn bad

If you abuse them, lithium-ion batteries can fail. Best-case scenario is your battery just won't work anymore. Worst-case?

Demonisation of e-cigs notwithstanding, lithium-ion batteries are known to be prone to exploding. You will have heard stories of hoverboards exploding, you may have even heard of iPhones exploding. What do e-cigs, hoverboards and iPhones have in common?

They all use lithium-ion batteries.

Why do lithium-ion batteries fail?

The most common cause of the runaway exothermic reaction (aka go boom) that can occur in lithium-ion batteries is degradation of one or more components causing chemical reactions that shouldn't occur. This degradation is most commonly caused by excessive heat. The heat breaks down the electrolyte sheet, or the circuitry that prevents overheating, causing a chemical reaction that causes more heat, that causes more degradation, that causes more heat... until the thing flares up like a firework.

Overcharging

If you push too much current into a LiON battery, there will be a build-up of heat that causes degradation of the electrolyte.

Over-discharging

If you try and draw too much power from the battery, again you will degrade the electrolyte, causing extra chemical reactions that will increase the temperature of the battery.

Overheating

Operating the battery at too high a temperature will cause the components to break down, damaging the circuitry that prevents excessive temperature.

Short-circuit

This goes for most batteries, but particularly LiON batteries. Creating a short-circuit will create a runaway heat situation that never ends well.

Stabbing it with a knife

Or any sharp object, really. Piercing the layers of anode, cathode and electrolyte will almost always result in a flare-up.

Lithium-ion batteries and e-cigs

LiON batteries have their dangers no matter what they are being used for, but e-cig owners need to be vigilant about:

1. Heat

We all love our massively subohm builds and giant clouds, and to get these we are going to be working with high temperatures. This is where the design of your mod is crucial - cheap knock-offs or just poorly-designed units can put the battery too close to the hot parts.

2. Charging

You've heard the mantra: "never charge your batteries unattended", and you'd do well to heed it. Even if you've got a proper charger with full-charge cutoff circuitry, you can't guarantee it will never fail. And even if it doesn't happen to explode in the charger, it can still explode in your pocket or your face when you fire your mod up.

3. Discharging

I get it. We're envelope-pushers. We get the most power we can to get the biggest, most satisfying clouds. Unfortunately, dragging too much power out of a battery is a great way to destroy it and possibly bits of yourself. It is crucial that you know what your battery is capable of before using it in a mod, especially a mechanical mod.

4. Non-genuine batteries

Hard as it is to believe, there are people in this world who care more about making money than human safety and welfare. Some of them may even get cheap, poorly made LiON batteries and re-wrap them so they can sell them for a higher price. With batteries getting harder to come by these days, it is absolutely vital you make sure you are buying genuine batteries.

5. Poorly-made mods

Genuine mods are expensive for a reason - people spend hours perfecting the design and only using the best materials. As mentioned in point 1, mods need to protect the batteries by avoiding short-circuits, over-heating and over-discharge. Knock-offs from people who don't know what they are doing are dangerous because these measures may not be in place.

How to vape and not end up on the news for all the wrong reasons

The reality is that the dangers of LiON batteries failing are fairly low all things considered. As an e-cig user, follow these steps to make sure you don't add to the toll:

1. Watch your temperature

If your mod starts to feel hot to the touch, give it a rest!

2. Buy a proper mod

Don't be a cheapskate. Save that little bit extra to get a properly-made device that has the necessary protections built in. This goes double for mech mods.

3. Buy good batteries

Refer point 2. Buy from a vendor you know is responsible.

4. Buy a proper charger

It needs to have short-circuit protection and full-charge cutoff features. And "never charge your batteries unattended".

5. Buy an ohms meter.

Building your own coils? Using a mech mod? Buy an ohms meter and don't push the envelope past its limits.

6. Treat your gear with respect

Just like your dog, don't leave your mod in the car on a hot day. But unlike your dog, rolling the window down won't help.

If you drop it, inspect it for damage. And by inspect it for damage, I DON'T mean try firing it up to see if it still works. Check your mod for any broken internals (as best you can) and don't use the battery until you've checked it with a multimeter.

Store your batteries at room temperature. Don't put them in the fridge, you'll wreck them. Just don't leave them in the sun or behind the TV.

Share the love

Now you have all this wonderful knowledge, don't keep it to yourself! Make sure all your vaping friends know how to use LiON batteries safely. At the very least you'll save $30-odd at the hospital flower shop.

Batteries are an irrevocable part of vaping life. Whether it's a little cig-a-like or a massive monster mechanical mod, they all rely on a battery (or batteries) to give you those sweet clouds of craving-killer goodness.

When you start vaping you start with devices that have built-in batteries, such as the aforementioned cig-a-likes or an Ego twist. But sooner or later, you will begin to experiment with mods.

Whether a stick or box mod, these devices generally involve advanced battery technology, and by extension, owning one pays to have advanced battery knowledge. You don't need to go get a degree in electro-chemical engineering or anything, but you do need to know the basics.

So bear with me here - I'm going to assume zero knowledge of batteries, and work my way up to advanced aspects that every vaper should know, whether you plan on getting the Snow Wolf or not.

What is a battery?

A battery is a self-contained cell that stores electricity for the purpose of powering electrical devices. I'm pretty sure you know the rest.

How do batteries work?

When you boil it down, all batteries work via chemical reactions.

All batteries have an anode (or negative pole), cathode (or positive pole) and an electrolyte (no, not Gatorade, a fluid or other chemical medium to act as a barrier between the anode and cathode).

The anode and cathode are made up of two different types of chemical compounds. Due to the chemical reactions within the cells, electrons build up at the anode causing a voltage difference (you may remember how voltage works from our earlier blog post about vaping and electricity).

Now electrons are fussy little beasts - they don't like being all bunched up, and would much rather spread themselves out evenly; therefore, all they want to do is go back to the cathode. But they can't, because the electrolyte is in the way. So they sit at the anode, elbowing each other for room and generally being rather keen to get moving.

When you close the circuit between the anode and cathode with a wire or other kind of conductive material, the electrons are free to go back to the cathode and finally get some personal space. As they flow along the material connecting the anode and cathode - voila - you get an electrical current.

This is how all electrically powered devices work. They draw current from one end, pass it through anything that needs electricity, then whatever is left over goes back into the battery.

Then why do batteries run out?

Remember that all batteries work via chemical reactions. As the electrons flow, it causes chemical reactions in the anode and cathode mediums that eventually cause them to stop producing electrons. This is why the voltage of a battery drops as you use it - the potential to produce a current drops as the chemical reactions progress.

So how do rechargeable batteries work?

All you are doing in a rechargeable battery is reversing the flow of electrons, sending them back to the anode like trillions of microscopic four-year-olds being sent back to their rooms. The chemical reactions reverse, and the process is ready to start again.

So, those are the basics of batteries. Now on to some more interesting stuff...

Chemical makeup

Different kinds of batteries will have different chemical mediums by which they produce electrons.

Your typical car battery is a lead-acid battery. Whilst they have a low energy density (that is, capacity to store electrons), they are capable of producing massive bursts of high current - perfect for quick zaps to power your starter motor. They consist of two lead plates and sulfuric acid dissolved in the electrolyte, which is typically water.

The average battery you buy from Bunnings to power your wall clock is an alkaline battery. They actually contain manganese dioxide and powdered zinc; they get their name from the alkaline electrolyte. These are your perfect batteries for prolonged, low-current usage. For longer lasting power you can pick up a nickel cadmium battery, which were the first kind of alkaline battery.

If you owned a mobile phone in the 90s you would be familiar with the nickel-hydrogen and nickel-metal-hydride batteries. These are more energy-dense and last longer than alkaline batteries and therefore can be made to be much smaller.

Lithium-ion batteries

Now we're back in the present day in the world of the lithium-ion battery.

Lithium is the third element on the periodic table. It's a very small atom; likewise the least dense of all the metals with the highest electrochemical potential and energy-to-weight ratio, making it perfect for batteries. However it's also very unstable, which is why, although lithium batteries were invented back in 1912, they were not used until the development of the lithium-ion battery in the mid 80s.

Things you need to know about LiON batteries

1. They are a slightly different animal to normal batteries. Lithium ions actually pass through the electrolyte to either the anode or cathode, depending on whether the battery is charging or discharging. The anode, cathode and electrolyte are actually sheets, not solid terminals in a liquid solution, so lithium-ion cells consist of the anode, cathode and electrolyte sheet wound around each other in a spiral.
2. Lithium is highly reactive. The last thing you want to do is get lithium wet. Remember back to high school chemistry, when the teacher put sodium in water? Think that, but like ten times more powerful. Which is partially why...
3. Lithium cells are contained under pressure. This is to keep any air or water reacting with the lithium. Therefore it is never a good idea to throw a lithium battery onto concrete as hard as you can. I mean it. Never.

So your lithium-ion battery is literally a metal canister jam-packed with a highly explosive chemical that is not unknown to occasionally catch fire! Kind of makes you think twice about having your next vape.

Fortunately for us, good LiON batteries have inbuilt safety features, which are:

1. A voltage sensor. If the sensor detects that too much current is being drawn, it will restrict the flow of electrons.
2. A temperature sensor. If the sensor detects that the cell is getting too hot, it will isolate the overheated part to prevent a runaway thermal reaction.

Note that I said a "good" LiON battery will have these...

Why you should be fussy about your batteries

A LiON battery will fail if you over-charge or over-discharge it.

You will over-charge it if you leave it in a charger that does not have a full charge cut off feature. Keep pumping those electrons into the battery when it's already full and the battery will let you know about it. If you're lucky it will just be ruined. If you're unlucky...

You will over-discharge it if you try to draw too much current through it. Drag 30 amps out of a 20amp-rated battery and you will degrade the electrolyte, causing the cell to overheat, and - again, if you're lucky, only ruin the battery. This is why a sound understanding of battery technology is non-negotiable for mechanical mod users - even with the battery's built-in safety features, the lack thereof in the mechanical mod can still mean you push them too hard and get yourself in trouble.

So...

What to make sure when buying high-current lithium ion batteries for your mod

1. Check the ampere rating. Back in the old days this would be represented as the "C" rating, however in these more enlightened times they just write it on the side of the battery. In order to determine if the particular batteries are right for what you are going to put them through, you need to understand Ohm's law and how to calculate the amps your setup will draw. Again, because we're such legends here at Vapoureyes, we have a blog post about this.
2. DON'T BUY REWRAPS! A rewrap is a battery that is not in its original skin, meaning that you can't trust the amp rating written on it. Past experience has told us that some unscrupulous characters have re-wrapped batteries with skins over-stating their amp rating, which means they can charge original price for a cheap knock-off, and you might have to suffer the consequences.
3. Make sure they are protected. Make sure they have the built-in safety features mentioned above. It's as simple as making sure your vendor tells you whether they are "protected" or "unprotected". If you're highly experienced and full of expert battery knowledge (or an electro-chemical engineer), you might be able to get away with using an unprotected battery if you're very very careful with your resistances. For the rest of us - buy protected.
4. Buy a decent charger. Make sure the charger you get has the full charge cut-off feature, meaning it will cut off the current as soon as it senses the batteries are fully charged.

A few other pro-tips:

• Learn Ohm's law.
• If you're using a mechanical mod, buy an ohms meter whatever you do.
• Don't leave them charging unattended - especially not overnight. You don't want to wake up with half your face blown off. You'll probably frighten yourself when you look in the mirror.
• Don't discharge them all the way. If a LiON battery gets fully discharged, it is ruined. Charge them up as soon as they dip below 20% or so.
• If you're using multiple batteries, get smart about whether to use them in series or in parallel.
• Don't drop them in water.
• Don't freeze them.
• Don't leave them in the sun.
• Don't throw them at people. It's not nice.

There's absolutely no reason to be scared of batteries. If you treat them right you will have no problems at all. But before you venture into the world of high-powered or mechanical mods, make sure you know enough to keep yourself and your loved ones safe. Batteries don't take abuse lying down!

For more information on battery and battery safety, please check out these awesome websites:

http://www.mpoweruk.com/safety.htm

http://www.livescience.com/50657-how-batteries-work.html

http://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm

If you haven't read our last blog post on all things vaping and electricity, please do so first before reading this post, as it contains information vital to understanding this one (I was tempted to call it "voltage and wattage and amps - ohm my!" - but I'm glad I didn't).

As we discussed in this blog post, mech mods used to be the only way to draw high power for sub-ohm coils, but these days we have high-powered regulated mods to do that job, and most mech mod owners stick to them for aesthetic or sentimental reasons.

Mech mods are still highly popular, and still better than regulated mods for durability. However, because they are not regulated and don't have all that fancy circuitry, they are not as safe, and require a degree of knowledge to prevent battery or peripheral limb destruction.

With this in mind, let's take a look at some of the most important things you need to know about using a mech mod safely, so that your batteries - and peripheral limbs - keep functioning as long as the maker intended.

Batteries - it's all about the batteries

Ah, the good old electrochemical battery - first invented by Alessandro Volta in the year 1800, with only modest improvements in functionality since then. Yes, the chemicals have changed, they've gotten smaller, and slightly safer, but they really haven't changed all that much in the past two centuries.

Let's not go into all the ins and outs of it - if you're really curious about how batteries work there is ample information on the Internet. For our purposes, we know that batteries store electricity, our mods need electricity, therefore we need batteries to power our mods.

What you do need to know is which battery is the right battery to put in your mod.

Choosing the right battery

Mechanical mods don't have the circuitry that senses the resistance of the coil, adjusts the wattage and voltage, prevents short circuits or overheating. A mechanical mod simply has a switch that connects your battery directly to your atomizer. If your resistance is too low, or your battery not powerful enough, all sorts of nasty stuff can happen, both to your battery and to your peripheral limbs.

I'm going to go out on a limb (no pun intended!) and say the only batteries you should ever use are IMR Lithium Ion batteries. The chemistry of IMR batteries is a lot more stable, meaning they can handle a lot more stress, deal with a lot more heat and are less likely to become volatile.

The only question you need to answer then is: what size, and what capacity? 18350? 18650? 26650? 1600mAh? 2000mAh? 2500mAh?

In terms of size, this will simply come down to what your mod is designed to accommodate. 18650 is by far the most common, fitting in 22mm-type devices such as the Nemesis or in box mods such as this one. 26650 are wider and are usually seen in really thick stick mods like the Hades.

Capacity is where it gets a little more complicated. Just because a battery has a higher capacity in mAh, doesn't mean you'll get more current out of it!

Back before battery manufacturers clearly told us, it was important to calculate the maximum continuous discharge based on the battery's C-rating using a fairly complicated formula. In these more enlightened times, however, it's a simple case of reading the battery specs to see what the max discharge in amps is.

In short, you need a battery that is capable of pushing the amps you need for the resistance of your atomizer.

Maximum Continuous Discharge Current

You will generally pick your mod and battery setup based on the target resistance you are aiming for.

Remember that the lower the resistance of your coil, the more power you will need to draw from your battery, therefore you will be looking for the one with the highest max continuous discharge in amps.

Ohm's Law

Here is where you will need to use Ohm's law in determining how much current your desired setup is going to draw, and in choosing the right battery for the job.

The formula you will need to use is A=V/Ω.

Your typical 18650 battery when fully charged will draw 4.2V, dropping to around the 4.0V mark for the majority of its cycle.

Let's say you want to build a 0.5Ω coil.

4.2/0.5 = 8.4 amps when fully charged.

4.0/0.5 = 8 amps for the majority of its cycle.

Therefore you will need a battery that is capable of easily producing at least a continuous 8.4 amps before you can use your 0.5Ω coil.

Most good high drain IMR 18650s will pump around the 20amp mark, so you will be perfectly safe with one of those. But if dealing with your stealthy little 18350s, you will be paying close attention to the rated max continuous discharge before going ahead. You will always want to leave yourself substantial headroom - constantly pushing a battery to its maximum rated discharge current is not good for battery life or peripheral limb safety.

Building coils for your setup

Most of the time, you will purchase your mod and batteries first, then set about building coils to suit your equipment, having made sure you purchased a mod and batteries that can handle what you are aiming for. In this case, you definitely need the following equipment:

• Ohms tester - you need to make sure your coil is in the right resistance range before testing it on your battery.
• Multimeter - you need to make sure your battery's voltage is reading correctly and there are no shorts.

Other random safety tips

• Buy a battery charger with a full charge cutoff so you don't overcharge your batteries.
• Do not completely drain your batteries - as soon as they drop to 3.6V, recharge them.
• Do not short circuit your battery! It leads to nothing good, either for battery life or peripheral limbs.
• Do not invert your batteries! Refer above point for why not.
• Do not stack your batteries unless your mod supports stacking. Box mods that can take two or more batteries are wired to cope with it.
• Make sure your mod has adequate ventilation holes. If it doesn't - make some with a drill.
• Make sure your mod has a fire button lock feature. Unintentional and continuous firing is bad as per points 3 and 4 above.
• For extra safety, you can install a kick to control the watts or for short-circuit cutoff.

Hopefully I have armed you with enough information to save your batteries and peripheral limbs, and to ensure your mech mod days are filled with cloudy bliss! Keep reading below for some more useful info if you are planning on really pushing your mod to its limits.

Massively sub-ohm

In these days of nickel resistance wire, clapton coils and multi-coil atomizers, you may find the below table fairly useful.

You can find the excel sheet and input your own data here.