Caring for your batteries
We would always advise that a battery cover or holder is used when transporting batteries to prevent them from touching each other, or other metallic items.
Make sure that your batteries are inserted the correct way to avoid them venting. Even if your mod features reverse polarity protection, pay attention that the batteries don't go in backwards.
When charging your battery, check back regularly to see if it has finished. As soon as charging is complete, remove from the charger to prevent it from overcharging, which can cause battery failure. Batteries should always be charged on a fireproof surface, and should not be left unattended or to charge overnight.
The chemicals contained within the battery should never be exposed to extreme temperatures so keep it at room temperature - and definitely keep it away from fire! Also, check for damage/denting regularly and do not use if any is found.
Use special caution when working with rechargeable Lithium Ion 18650 cells and make sure you have enough knowledge of Li-Ion batteries in charging, discharging and assembly before use.
Li-Ion battery condition
If you want your Li-Ion battery to last, don't let it empty completely. These batteries do not need to be discharged all the way to prolong their life in the same way that Nickel based cells do. Instead, get into the habit of recharging before the low battery indicator shows on the mod.
You can also extend the life of the battery by staying above 2.5V. Dropping below 2.0V leads to metal being plated inside the battery which can lead to a short circuit, or possible bursting. Bear in mind that this is the resting voltage, not the voltage 'under load' that the battery drops to when used.
If you do happen to discharge your battery below 2.0V, you should charge immediately at the slowest rate your charger will allow. Once it gets above 3.0V, you can switch back to normal charging rate.
If the battery has been at 2.0V for a while then, the chances are it is damaged. Trying to charge or use at this point may lead to a short circuit.
You should allow the cell to cool to room temperature when you remove it from your mod before attempting to charge it. Also, never use a trickle charger with this type of battery as the continuous holding of the battery at trickle charge voltage will damage it.
All devices used with rechargeable Lithium Ion IMR batteries should have an amp limit of 20A or higher. Using other batteries can be potentially hazardous.
If you start to get battery alerts from your mod earlier than before, it doesn't hit as hard, or it gets warmer during use, it may be time to replace the cell.