Battery Safety

Battery safety is a big thing in vaping. As vaper's we use batteries all day every day, so it is very important to have at least some basic knowledge of how they work and what their operating conditions are. Using poor quality batteries can result in poor performance in some cases shorts or thermal runaway happens far before the supposed operating perimeters. For the most part, vapers that use regulated mods see far less performance issues from lower quality batteries than users of mechanical mods.

Amp Limits
If you are a mechanical mod user, knowing your batteries amp limit is absolutely necessary. Depending on the kind of build you typically use you can better choose a battery with an amp limit to suit your needs. Mechanical mod users that sub ohm are more likely to have misshapes with their batteries as a result of over stressing their batteries. Another very important thing to consider when using a mechanical mod is using or switching to "Safe" Chemistry high drain IMR batteries. These safe chemistry batteries are better used in situations where thermal runaway might happen, these batteries DO NOT explode or catch fire when shorted out. This does not mean however that they don't vent hot gasses like most batteries, but unless it's trapped in a mod with no vent holes it probably won't explode. As far as I am aware the Sony VTC5 batteries remain the holy grail in vaping, partly due to them being the only battery with a true 30 amp continuous rating. Sony VTC5 batteries are no long made, so chances are you will have to deal with one of the batteries listed below if you are in need of a sub ohm battery.

LG HE2 20A
Samsung 25R 20A
MNKE 1500 MaH  20A
Efest Purple 2500 Mah 20/35A

Charging/Over Discharging 
When dealing with batteries in an environment that has no safety precaution (Mechanical) it is very important to make sure your batteries are maintained properly, charged properly, and swapped out before they reach 3.5 volts. Batteries being used with a voltage of less than 3.5 volts have a higher chance of reaching thermal run away due to over discharging. Batteries that have been over charged often suffer the same fate as over discharged batteries. Over charging is often a sign your battery wearing out as a result of stress and should be discarded immediately. A multimeter will be your best friend, and could save you a nasty accident. Another option is a battery charger that monitors and displays battery voltage. The only charger I know of like this is that Nitecore D2 & D4 battery chargers, I own the D4 and love it.

High Wattage Box Mods
Many of the new high wattage box mods hitting the scene require 20A and sometimes higher rated batteries. This is because of the much higher amount of power required from the battery to produce 100 Watts or more. Typically speaking 20A batteries are perfectly reasonable for use in mods below or at 100 watts. That I know of there are only two mods around at this point in time that may require true 30A batteries, the SMY GOD and the Vicious Ant Variant. In these cases it may be wise to attempt to find some VTC5 or equivalent.

Standard Wattage Regulated Mods (10-20 Watts)
The use of high drain IMR batteries is not necessary in a majority of lower wattage mods and can be an unnecessary expense for some vapers. I have had plenty of success using standard 10A rated Li-ion batteries in these kinds of mods with no noticeable performance hit. If you are in a circumstance where you are using multiple mods,having some with higher power requirements, I would recommend using IMR batteries in all mods and eliminating the possibility of mix ups.

Hopefully I have provided enough information to at least start people off in the right direction. Thermal run away is not a pretty thing. The more of us who practice safety when using our vaporizers the better. If enough of us fuck up and blow up our mods, they'll find a way to outlaw vaping for good. None of us want that. So, with all that being said,

Be Safe,
Keep Calm,
Vape On!

P.S.
This post will likely end up in the sub ohm / Mechanical section, along side some other materials that will help make things a little bit simpler.