Battery Warning and information:
IMR Batteries:
Do not discharge below 2.5 volts or cylce/life performance will be reduced
Do not carry batteries loose in a pocket or purse; metal objects may short the battery.
Do not charge battery past 4.2 volts. Remove battery from charger when fully charged.
Do not charge unattended. Do not use with charger not specified for device.
Recharge empty batteries (resting voltage~3.6volts) as soon as possible. Leaving batteries in discharged state will incur irreversible damage.
If the wrapping/battery is visibly damaged, discontinue use.
Do not throw away in the trash. Please Recycle.

Chipped batteries (ego twist, MVP, etc):
Have short circuit/atomizer and over-charging protection
Will shut off at a voltage of 3.6 volts
Make sure connections are clean on battery and charger before charging.
Remove battery from charger when light turns green. Do not overcharge.
Do not charge unattended. Do not use with charger not specified for device.
Do not throw away in the trash. Recycle.

COILS

What resistance coil should I get?

The resistance of coils are measured in ohms. The more resistance you have, the less electrical current flows through a coil.     

The higher the resistance, the cooler and smoother your vape will be.

The lower the resistance, the more throat hit and vapor production you will get. Low resistance coils will drain your battery faster than high resistance coils, and the coils may have shorter lifespans themselves.

Coils less than 1.0 ohms may not be recognized by your device if it has a computer chip in it.

If you use a variable voltage/wattage device, turning up the power or voltage too high on a low resistance coil may burn the coil. Turn up power/voltage in increments. Do not pair low resistance coils with high power/voltage settings. 

Mechanical Mod Safety


Mechanical Mods do not have protective chips (unlike Chipped Mods).


This article from ecigarettereviewed.com explains proper Mech Mod Safety.

Polycarbonate Tanks

Certain liquid-tank combinations do not play well together. This may be anything from causing a crack to develop in the body to outright melting the outer casing of the tank.

The good news is that only a relatively small proportion of juices are implicated, and the problem only occurs with plastic tanks. It might not be ideal for you financially, but the risk is removed if you spend a little more for a glass tank.

• Only polycarbonate (plastic) tanks are affected, so to remove the risk with specific flavors, invest in a glass one!
• Malic acid, citric acid (both common in fruits) and cinnamon-based liquids are the most common culprits, but there is a master list on the ECF you can use to check specific juices.
• Clean up any spills carefully, remembering that nicotine is a toxin and can be absorbed through the skin. Wipe down affected surfaces, take off and wash any clothes it spills on and put any juice-sodden paper towels in a zip-lock bag before throwing them away.

BATTERIES - Types, Use,  and Science

We found this forum post to sum it up very well.
Thank you CraigHB from The Vapers Den:

IMR is a product code.  "I" stands for Lithium-Ion, "M" stands for the Manganese based chemistry, and "R" stands for rechargeable. 

ICR is again a product code.  Same as before except "C" stands for the Cobalt based chemistry.

Only the round cells commonly use these designators.  There are flat cells or prismatic cells that use a Li-Ion chemsitry, but it's usually polymer based (plastic).  I've never even seen the code designator for that.  Everybody just calls them LiPo cells.

High drain means that the cell can handle high output currents.  ICR cells are usually limited to 2 times the charge capacity in output drain.  So, for example, a 750mAh 14500 ICR cell would be limited to two times 750mA or 1.5A.  This is why this type of cell must be protected.  It has the lowest drain capability and the highest volatility or flammability in composition.

IMR cells typically have an 8C drain limit which is 8 times the charge capacity.  A IMR 14500 with 600mAh can handle 4.8A.  This chemistry is less volatile than the Cobalt chemistry and has much higher drain limits so they are typically not protected internally.  Though, they should have some kind of external protection because they can burn too, just not as easily.

LiPo and prsimatic cells can range in drain limit anywhere form 1/2C to 60C.  They are slightly less volatile than ICR and a little more than IMR.  They are typically not protected internally and should have external protection electronics.  These are the type of cells you find in digital cameras and cell phones.

Generally speaking, you only use an IMR cell when the device specifically calls for one.  IMR cells are required for boosters (single cell VV or VW) because boosters require higher drain.  With a booster, you're going from lower voltage to higher voltage.  That means you're going from higher current to lower current.

IMR cells may also be required for unregulated mods if the cell is small.  For example, you are limited to 1.5A with an ICR 14500.  If you want to use an LR atty with a cell that size, you need an IMR cell.

In the end, the size of your cell boils down to what you want in run time versus size.  That's always the big trade-off.  If you want a smaller device with a smaller cell, you'll have less run time.  If you want more run time, you'll have to tolerate a larger device with a larger cell.

Size numbers are based on a metric scale.  An 18650 is 18mm x 65.0mm.  A 14500 is 14mm x 50.0 mm.  A 14500 happens to be the same size as an AA battery.