Can I sub ohm

[FFPetz]

That is the thing though, as heat increases, resistance decreases. Therefore, any build on any battery will vent eventually if you fire it long enough. Some of them are slightly longer than a good hit, some of them take will take minutes or hours.

 

[supertrunker]

That is the thing though, as heat increases, resistance decreases. Therefore, any build on any battery will vent eventually if you fire it long enough. Some of them are slightly longer than a good hit, some of them take will take minutes or hours.

No it won't. If you build within the constant discharge parameters, the battery will just run down.

T

 

[nomad23]

I don't think the mod is the issue. Kanthal at the heavier gauge has a longer ramp up time. So it runs down the battery faster. And dual coils will run down your battery even faster. Actually even a single coil at 0.3 is going to run down the batt fast. I don't go below 0.5 because I don't like the flavor when it gets that hot. I usually stay between 0.7 and 1.0. And I decided after experimenting with dual coils that I prefer a single coil build. Also I switched from 24G to 28G Kanthal. It ramps up faster and has a bit less heat which in my opinion tastes better. And my V6 will run the coils I like just fine. But I do also use a Knight clone. Notice I said "prefer" and "opinion". That's what a lot of RBA vaping is about once you get the safety stuff down.

My vape isn't hot at all.. and the reason my caterpillar was getting hot was because of air flow. I made a new top cap and it got better. With the mutation x v2 nothing gets hot at .21 ohm duel coil build. I like single coils too.. just having to wick it more is annoying to me..

 

[nomad23]

Yes, calculate ohms law at 4.2, the full output of a charged battery.

For the other posters who didn't understand, OP is calculating amps using ohms law with a lower voltage and a .21 ohm resistance. Despite the typos, it is correct, except that 4.2 volts should be used for the calculation.

Also, 25R is a good battery for sub-ohm vaping. They are 20 amp continuous batteries with 100 amp pulse rating. I interchange them frequently with vtc5 at .21 ohm. They work great. I personally wouldn't use them for builds below .2, but some people do and I haven't heard of any issues yet.

Checking for shorts is simple. Put the rda on your ohm meter and check the resistance, then put the cap on and check it again. As long as the numbers don't change (or the meter reads a complete 0 or won't read at all), there's no short. Also check and make sure the only thing the wire leads are touching are the posts they are inserted into and the coil is not touching ANYTHING and you'll be good.

I have shorted and RDA before and it made a really weird noise and smelled like crap the second I hit the button. Battery never vented, and I could instantly tell something was wrong. That may not always be the case, but very rarely will a dead short go unnoticed and cause a battery to vent.

The other thing to keep in mind (and this is where things start to get shady) is that when you find the rating on these high drain batteries, it's typically the "continuous" amperage and that is usually firing the battery for longer than a couple seconds. You can always find spec sheets for the major batteries (sony, samsung, panasonic) and they typically state what the pulsing amperage is as well, and how long a pulse is. The other brands (MXJO, EFest, etc.) are typically rewrapped versions of the major brands.

I assume all my charged battery voltage (4.2v) gets to my atomiser - that i have a perfect device, with no losses from switches, dirty contacts along the way.

This is patently untrue, but what it does do, is to build in a little headroom - for safety if you like, into anything i build.
If i then build to the maximum ability of the battery's continuous discharge rating, then i'm cool! If i build to a mythical pulse rating, i'm guessing.

I don't like guessing.

With my mythical perfect mod and a 30A constant discharge battery, Ω = volts/Amps = 4.2/30, so a 0.14Ω build is the lowest i can go. Be very careful when you begin making assumptions like this - there is a margin of error in your measuring devices.

If you assume (hope!!) your battery can take a pulse rating, you may be mistaken. If i build that coil above at 0.14Ω and i fire it nonstop - even by accident, then the battery will run down, my wick will likely burn and the atty will get hot. No harm done.

If i build to the pulse rating of the battery - typically 60A or so and fire that for a long time - say in my pocket for example - the battery will likely vent (it will not explode necessarily) but if that happens in my pocket, i'll be known as Lesstrunker.

Be safe.

T

Look, I am running. 1 on a clone right now, just cause it didn't cost much doesn't mean the mod itself can't handle subbing. Your batt. Is mostly what would b the cause. However your rda that is heating up is normal as is the quick drainage. When you do extreme subbing you really don't want to be puffing hit after hit. Also be aware that as your batt. drains your voltage lowers and makes things pretty hard on it so don't let it go below half. Maybe buy another batt. To switch out as the other charges. As for blowing clouds, it's not just about sub ohm coils, a ton has to do with wicking and airflow. There are a lot of tutorials on YouTube that can help. If you ever do feel your mod heating up down by the button STOP! if it continues to heat up open your mod (if you can) and drop it in Salt water for a cpl hrs to drain. Your battery will still be shot but you save your mod and maybe more.

Im using a mutation x rda on a klone mech mod running it a .35 ohms off a efest 18650 battery coils are 24 gauge 6/5 wrap and for cotton less is more with this set up good flavor and definitely made for chasing clouds if your into that im thinking on going down to .23 ohm which is still below the max continuous out put of 20 amps and 35 amp pulse

Yea sorry about the confusion guys, I'm new to the electrical lingo.. I got mixed up on the whole watt-amp thing.. all I do now when I'm not working or playing with my kids is learning about the safest way to chase clouds.. I was running a .7 build until I got a better ohm tester then an avp and some good sub ohm batteries. With my current build I am getting decent clouds.