Sarah_1988

Rubbing alcohol also has a corrosive property to it, you might want to remove the seal rings asap so they don't get damaged.
I don't drink either but I keep a cheap bottle of vodka around to soak my tanks. You might want to consider that as an alternative. I think I paid about $6 for it and it's 6 months old, I still have  about 3/4's of the bottle left. It's worth the price for cleaning your expensive tanks without damage.

Use water rather than rubbing alcohol. Rubbing alcohol leaves a residue that's hard to get out.

It should just cycle thru the options with the same method for putting it in TC mode. You're looking for the initials to change in the window (in your pic the "NC") will change thru the various ccoil materials)

Does your TC mode match the material of your coil?
Ni - nickel
SS - s tainless steel
Ti - titanium
 
it cant be just any mode it has to match what your coil is made of (the actual coil itself, not the case or housing). 

The manual that came with it should tell you how to switch modes. Three fast clicks of the fire button switches the modes. I have several of the Kanger 75w TC box mods, before you put the tank with a new coil on, press the fire button until 9.99 flashes, or it may read the last coil instead of the new coil. Also sometimes you will have to push the pin in the 510 connection in the base in a little because the coils may vary slightly in length. When putting a new coil in make sure there is not a O-ring from the previous coil stuck to the base, which does happen or the new coil may have 2 O-rings instead of just 1, in either case it will leak. Personally I haven't had a coil with 2 O-rings on it, but other people have reported it. Lastly going back to the coil length you may have to pry the center pin on the mod up a little, they advertise a spring loaded pin, but the spring isn't very strong, and doesn't put much pressure on the pin.
Your pic shows your mod is in NC mode which is for Nichrome, you should be using Ni mode which is for Ni 200.

Here is a link to rebuilding a Subtank mini RBA, it is a older style RBA, but the basics are the same. rebuilding is not for everybody, but it does save a lot of money.
http://allaboute-cigarettes.proboards.com/thread/50745/kanger-subtank-mini-build-guide

It is much cheaper, I use RBAs exclusively in my subtank mini tanks, and haven't bought a coil for them in a long time. Premade coils can be bought, but I prefer to make my own. a little bit of mechanical aptitude is needed even when using premade coils. There are lots of videos on the subject.

Re-Buildable Atomizer
In this case, it's a deck (bottom part) that goes on your tank that allows you to build your own coils for it.

Thank you everyone. I actually ordered a Subox mini yesterday so I am hoping that will be better. I know it's probably not the best upgrade I could get but it's what I have the money for until I can purchase the alien kit.

Sent from my 9020A using The Vapor Talk mobile app

The Subox mini uses a 18650 battery, I hope you ordered one for it, I use the LG HG2 battery in my Subox mini mods, but there are other batteries available that will work just as good.

The Subvod mega to the best of my knowledge uses the same tank as the Subox mini. They both use the Toptank mini, so the coils you currently use will work. The biggest difference is the Subox mini kit should come with a RBA. I currently use 2 Subox mini 75w mods, and never get close to using 75w. The most watts I have used with that tank was about 35w and that was with a .5 Clapton coil.

I agree with bebop,save your dough,time for a new mod,if you already have the ni200 coils on hand,you can use that same tank on an istick 40 watt tc,they are inexpensive, have a higher battery capacity, and still the internal battery you are used to.they only support nickel in tc mode,but if that's what you are already using, I don't see a problem.I think you would be pleasantly surprised by this mod,it is very simple to use!

That .5 clapton doesn't start singing til about 30watts and that's approaching the limit of the subvod.  Avoid it.
A regular ssocc .5 should be okay.
Truth is the subvod is really an entry level kit and you are finding that it just under performs a bit for your needs.  I think it's fine as a pocket device to get you thru a couple of hours but it's not an all day affair.  It just has a quick drop off aftrr an hour, especially with any sub ohm coil.
 
Save your dough.  Sounds like you might be ready for an upgrade soon.

Sounds like a low battery warning, have you tried cleaning the connection? take the tank off and clean the connection with a Q-tip, see if that helps, or you might have gotten juice in the switch. You can also plug it in and use it as a pass through.

They usually last longer than 3 months, do you charge it until the light on the bottom turns green?
there has been reports of the Subvod battery not lasting very long.

Your battery is running low.  Dont forget to clean the charger too.  Those subvods take a long time to charge fully. Like 3 - 5 hours

Subvod mega might take longer, it has a 2300mAh battery instead of 1300mAh battery.

Which coil are you using? If you are using the .15 coil it might be your resistance might be dropping below the .10 ohm cutoff point.

Thank you for all of you info everyone! I actually do switch flavors a lot, trying to achieve that flavor. I looked up the alien kit and am strongly considering it, it looks like a really decent vape, if I can learn how to use it 😝 But I always research the proper ways to use something before I even recieve it. Is it relatively easy to use? I am impressed with the wattage on it versus what I've been vaping with the Subvod mega. 

Everybody has different vaping styles.  Or different vaping techniques. All of these variations lead to different performance. Different flavor.  Different coil life.
 
I have pretty good working hypothesis on this.  My wife and I use the same coils and tanks.  We both vape a variety of juices. She goes thru coils twice as fast as I do.  Sometimes we even use pre made coils but most of the time we use coils I make myself.  She says to me, "can you check my coils?"  I take a hit off her rig.  GAUGH!!!   Terrible!  I just made these coils a few days ago. My coils last 2 weeks sometimes with just a drop off on flavor but nothing close to burnt.
How is that possible?  
We have completely different vaping styles.  I like LOTS of airflow.  I take relatively quick, hard pulls with lots of airflow.  On a cool coil I take a couple primer puffs just as I fire the mod, not inhaling.  Then, I do a nice deep and brisk pull. I get lots of flavor and vapor. I vape higher wattage than she does.  Yet, my coils last twice as long.
My wife, on the other hand, fires her mod then starts to nurse her hits. These long, gentle draws.  You can hear the juice cooking on the coil.  She gets way less vapor.  The contrast to our styles is either end of a broad spectrum.  I'm sure everyone varies between these extremes and some fall outside of these extremes.
but I'm pretty sure that coil longevity is tied to juice flow rate and airflow.
there's a good chance that if you are prematurely burning coils up, then your airflow rate is too low for your wattage setting and the juice is just sitting there cooking on the coil.  I'm not really saying it's wrong or right to vape one way or another.  But I do think it explains why different people have different results to the same coil.  
Not all coils are the same, for sure.  I think most experienced vapers develop a sense for how much air to cpull over that coil.  There's a little sweet  spot in there you can feel and hear.  And any "low watt" vaper probably has experienced the sensation of pulling too much air over a coil too which can be pretty unsatisfying as well.  Just lots of air.
 
just my thoughts on it

X2 on the smok kit with baby beast. I'm looking to pick that setup up here soon. The tfv8 is a great tank too, but like all my other flavor chasing cloud making tanks, coils just don't seem to last. I had high hopes for the tfv8,but alas I'm burning thru coils every other day it seems. I have 2 triforce tanks and the tfv8 blows them away for both flavor and production but the coils have the same short lifespan. I had a tfv4 and traded it off because of short coil life. I can't speak to the coil life on the baby beast, I can't see myself using it much as it's too small for my chain vaping self.
 
I've tried changing juices up, still short coil life. I maitre mine with the puff counters, which kinda sucks cause one tank trends to ride the same mod all the time. Lol
But I've accepted this as vape life. My tanks drink juice, but flavor is what I'm after.

Do you vape the same flavor all day or do you change flavors a couple times a day? If you vape/chain vape the same flavor for too long, your tongue will lose the ability to taste that eliquid. If you change your flavors, for example you're vaping a fruit flavor, change to something completely different like apple pie (bakery) for a little while then go back to the fruit flavor and you should be able to taste it again. It might not be your coils...   

I have a couple of Subvods, depending on the juice the coils can last a couple of weeks sometimes. the darker the juice the shorter the coil life, also sweeter juices can gunk up a coil pretty fast. One flavor I vape is a coffee flavor, and I usually only get 2 tanks max on a coil.

Welcome to VT.  Be prepared for lots of questions, lots of advice and lots of recommendations.  
As @Tam mentioned, you may just need to mix up your juice flavors.  For some people a single flavor works, for others, we need a variety.  As @FXRich mentioned, darker and/or sweeter juices can be rough on coils.
If you truly want to upgrade to something else, then I can make some recommendations, but those recommendations would depend on what a reasonable price is to you.  What I find reasonable may not be reasonable to you, or your limit may be higher than I find reasonable.  Kanger makes fine products.  I started with a Kanger EMOW kit and own a couple of Kanger tanks.  There are several Kanger products that might interest you in the Vapor Talk store.  Personally, though, I am partial to Sigelei regulated box mods.  I currently own four of them; an older Sigelei 100+ and three Sigelei Fuchai 213's.  They don't, however, come bundled with a tank (though you might find a vendor that has a "package deal").  
For tanks, I have been vaping on the SMOK TFV8 Cloud Beasts and Baby Beasts.  The flavor production of the Baby Beast is nothing short of phenomenal, but it only has a 3ml capacity, which doesn't work for a lot of people (in fact, as a daily driver it doesn't work for me, either).  That being said, I went through more tanks than I bothered to count on the Baby Beast before I had to change a coil,.  The reason I had to change the coils wasn't because it lost it's luster.  The reason was because during a rather intoxicating chain vaping session, I let it go dry and burned the cotton.  I have no doubt I would have gotten several more tanks before the coil absolutely had to be changed.  That was with dark juices, light juices, sweet juices, not so sweet juices, fruity flavors and dessert flavors.
Alternatively, SMOK also just released the "Alien Kit", which includes their new Alien 220 watt regulated mod and a Baby Beast for about $60 (shop around).