Quick little summary.
Your IPV4 is your "battery" it simply supplies the power, for safety the only real concern is if it stops working properly or heats up, if either of these things happen stop and figure out why and fix it.
Your drip tip is simply a mouthpiece, you could vape without it sucking on the tank but that's a little weird.
Now, your tank, inside it holds juice and at the bottom/in the middle is a coilhead. It contacts the bottom portion of the tank where it accesses the electrical charge. The coilhead has holes in it to allow juice into the wicking material (usually cotton though there are others) and makes contact with the actual coil which is producing the heat via the electrical current.
Now, what it sounds like you're experiencing is a "dry hit" which basically means the wicking material has run out of juice and the coil has overheated, this produces initially very warm air then eventually will burn the cotton.
Now solutions to your issue if this is the issue you're experiencing.
First your vaping habits, do you take very long draws? Try shortening them and breathing in harder, this will increase the airflow helping to cool the coil as well as reducing the amount of time you're firing the coil. Then also the time between hits, this isn't magic it's all just physics, there is a limit to how quickly your material can wick the juice, if you're exceeding that you're going to experience dry hits. Remember that the juice doesn't just produce the vapor, it also acts to cool the coil while it's vaporizing pulling the heat away from the coil.
Next I'd look at your wattage, you may actually prefer changing this instead of your habits, reduce the wattage and you'll produce less heat on the coil meaning less vaporization. At a lower wattage you could potentially still take long pulls frequently without the dry hits.
Then lastly your juice, again maybe this will solve your problems without the other two as well. Liquid is made up primarily of 2 things, VG and PG. VG is thicker while PG is more viscous. Most high end juices are primarily VG, however for many tanks (especially older ones like what looks like a Kanger subtank) the high VG juices simply don't play nice. Getting a higher PG juice would help this situation. To note though PG also produces less clouds though a stronger sensation on your throat. 50/50 is where you're generally going to want to be at for a Kanger Subtank with their standard coilheads.
If that sounds like your issue try one of these things and see if that helps. Again, it's not magic it's all just physics, there's going to be a solution for every issue but you have to learn how things work to figure out what it is. Hope this helps, and again this is just a quick summary, there's a lot to learn if you feel the desire.
