Dumb Mech Questions

[OBDave]

Hokay, so, this is the world...round...I've done a day and a half's worth of searching, but some of this stuff is still escaping me.

I've got a K100 and Igo-W rebuildable dripper on the way (Slowtech, could be a month before I see them), and I'm doing tons of research to try to be as prepared as I can before they arrive.

1. With a mech, power delivery starts out at 4.2v and then decreases as the battery drains, right? So if I'll be using a battery with a max draw of 10 amp (Panasonic NCR18650PD), I need to figure my lowest safe ohm coil based on 4.2v when fully charged, right? What ohm coil can I put on this safely? I had a girl at my local B&M today say she was running 0.2ohm with a sequential 0.4 dual build, and was complaining that her battery was getting weak - sounds dangerous to me.

2. Doesn't such a massive power level end up burning a lot of juice? Not as in going through it (I know that's coming), but making it taste like toasty crud? My wife and I have a lot of juices we like that hit at their best around 3.2-3.6v on our twists with 2.0-2.4 ohm coils (which is all we know at this point) - are they going to be completely worthless at high power?

3. I know that I need to test the resistance of any coils once installed before using - so I bought an atomizer resistance tester. But I've also been reading that I need to get a multimeter and that I should pull the battery every 10 or so puffs to test the battery charge - I assume this is important since it's garnered a sticky in the rebuildable section (post 2, bullet point 4) - why would anyone want to vape this way given all the extra work and the necessity of carrying all these tools around wherever you go?

4. With a dripper, how long will I be able to hit the atty before refilling? Should I plan on dripping on the wicks, taking 10 puffs, then taking the whole thing apart to test the battery, re-juice the coils, and then re-assemble to take another 10 puffs? It almost sounds like I'll be spending more time working on my mod than actually hitting it, especially considering building coils and boiling cotton and praying five times daily to the gods of ohm and whatnot...

 

[Royaldrunker]

Your battery charges to 4.2 volts

When you fire your mech with an atty load, your volts will drop dependent on mod contacts quality of battery and resistance of your topper
Most voltage drop tests are done at 1 ohm load on a charged battery.. So youl will here a lot about voltage drop and mods.. .5 voltage drop will give you 3.7 volts for example...and you should expect around 3.7-3.9volts on a k100, depending if you cleaned and sanded contacts and threads

Cheers

 

[Royaldrunker]

The rest of your questions are about proper safety.. On your builds and very subjective, someones sweetspot might be 1.5ohm 1 or .3 ohms

Read lots before you head down subohm...levels

 

[Bshollow]

The safety of your coil builds will be completely dependent on your battery's maximum amp draw limit . For example, a Sony US18650VTC4 has a maximum amp draw limit of 30. Let's assume, for safety's sake, you have no voltage drop due to your device, and you throw out 4.2 volts on your first hit. Theoretically, you could build a coil down to .15 ohms and that would put a load of 28 amps (Amps = Voltage/Resistance). I would highly not recommend ever attempting that. I wouldn't recommend taxing your battery more than 70% of it's amp limit, which would mean your threshold would be 70% of 30 = 21. With that threshold to attempt a reasonable margin of safety, you would want to keep your builds at or above .2 ohms. Obviously, don't even try that out of the gate, if ever. However, with a 1.0 ohm build you are only taxing your battery 4.2 amps, which is well below your battery's limitations. The battery is THE MOST IMPORTANT thing in your mech set up to achieve a reasonable safety margin. You MUST build your coils around your batteries limitations. There is no getting around that.

 

[MamaTried]

Hokay, so, this is the world...round...I've done a day and a half's worth of searching, but some of this stuff is still escaping me.

I've got a K100 and Igo-W rebuildable dripper on the way (Slowtech, could be a month before I see them), and I'm doing tons of research to try to be as prepared as I can before they arrive.

1. With a mech, power delivery starts out at 4.2v and then decreases as the battery drains, right? So if I'll be using a battery with a max draw of 10 amp (Panasonic NCR18650PD), I need to figure my lowest safe ohm coil based on 4.2v when fully charged, right? What ohm coil can I put on this safely? I had a girl at my local B&M today say she was running 0.2ohm with a sequential 0.4 dual build, and was complaining that her battery was getting weak - sounds dangerous to me.

2. Doesn't such a massive power level end up burning a lot of juice? Not as in going through it (I know that's coming), but making it taste like toasty crud? My wife and I have a lot of juices we like that hit at their best around 3.2-3.6v on our twists with 2.0-2.4 ohm coils (which is all we know at this point) - are they going to be completely worthless at high power?

3. I know that I need to test the resistance of any coils once installed before using - so I bought an atomizer resistance tester. But I've also been reading that I need to get a multimeter and that I should pull the battery every 10 or so puffs to test the battery charge - I assume this is important since it's garnered a sticky in the rebuildable section (post 2, bullet point 4) - why would anyone want to vape this way given all the extra work and the necessity of carrying all these tools around wherever you go?

4. With a dripper, how long will I be able to hit the atty before refilling? Should I plan on dripping on the wicks, taking 10 puffs, then taking the whole thing apart to test the battery, re-juice the coils, and then re-assemble to take another 10 puffs? It almost sounds like I'll be spending more time working on my mod than actually hitting it, especially considering building coils and boiling cotton and praying five times daily to the gods of ohm and whatnot...

your questions ain't nowhere close to dumb. they are quite possibly the most intelligently posted questions on this topic from a newcomer, that i have ever seen.

1. ignore that girl at the vape shop. she's dangerous. here's two threads that will be well worth reading :
this one may contain info you already know, so pick and choose:
http://www.e-cigarette-forum.com/fo...op-reference-shop-new-experienced-vapers.html
this one will answer remaining questions about battery safety:
http://www.e-cigarette-forum.com/fo...-discussion-safety-battery-info-warnings.html

2. yes. most mech users go lower ohms and usually end up using more juice.
3. it's not really necessary to have a multimeter if you have an ohmmeter to test for shorts. most folks can tell when the battery should be changed because the vape seems weak when the battery gets down to about 3.6-3.7. some, like me, are slow learners, but after a while even i can usually detect when to change my batt. that said, i also use VV and VW devices. different strokes...
4. this depends on the dripper. some only handle a few drops, others much more. in general, drip the number of drops you see mentioned on ECF for that dripper, and re-drip when the vape tapers off. you will need to re-drip many times before you need to swap the battery.

you can also drip with a VV or VW. that way you are only introducing one variable at a time. why introduce 2 new things at one time?


hope this helps

 

[humpstyles]

Your questions were perfectly posed for another sub-ohm novice like me. I do a ton of research everyday on the matter, and they definitely helped me see where others (yourself) are having questions as well. Thanks.

 

[MoBait]

2. Doesn't such a massive power level end up burning a lot of juice? Not as in going through it (I know that's coming), but making it taste like toasty crud? My wife and I have a lot of juices we like that hit at their best around 3.2-3.6v on our twists with 2.0-2.4 ohm coils (which is all we know at this point) - are they going to be completely worthless at high power?

3. I know that I need to test the resistance of any coils once installed before using - so I bought an atomizer resistance tester. But I've also been reading that I need to get a multimeter and that I should pull the battery every 10 or so puffs to test the battery charge ...

4. With a dripper, how long will I be able to hit the atty before refilling? Should I plan on dripping on the wicks, taking 10 puffs, then taking the whole thing apart to test the battery, re-juice the coils, and then re-assemble to take another 10 puffs? It almost sounds like I'll be spending more time working on my mod than actually hitting it, especially considering building coils and boiling cotton and praying five times daily to the gods of ohm and whatnot...

2. In my limited experience, as long as you keep the wick saturated, the vape from your RDA will taste great. I think the reason you get a burnt taste with cartomizers when cranking up the voltage is that the wick cannot saturate fast enough.

3. It's nice to have a multimeter so you can check battery voltage and build resistance but there's no need to check the battery every 10 hits. You can check after vaping for 30 minutes or so. After going through a few batteries, you'll get the feel for how much juice you got left. Also, if you do get a multimeter and plan to use it for checking resistance, make sure you check the resistance of the multimeter's leads by touching them together (I've seen 0.0 - 0.2 ohms in various meters), then subtract that number from any reading you get.

4. The amount of hits your RDA will deliver between dripping depends on the deck design and what kind of build you're running. I've had builds that gave me 8-10 hits and others that only delivered 2-3.


If I may make a suggestion, if you're not satisfied with a build, try changing the way it's wicked before ditching the coils. It saves time and you may be surprised with the results.

 

[el Jexican]

2. As someone stated before, as long as you keep the wick saturated your juice won't taste burnt. Depending on the build it will bring the flavor out better. I usually keep my coils between .4-.8ohms and run micro and nano coils....The flavor is amazing.

3. Multi meter is nice to have around and they aren't very expensive. I would say they are a must but you have a ohm checker. I still say it would be a good idea to get one.

4. It all depends on the build and the way its wicked.

 

[Baditude]

Sub-ohm Safety Check List:

• Always measure the coil resistance before firing it for the first time on your battery.
  
  
  
• Know your battery's amp limit (continuous discharge rate). (List of high drain batteries with amp limits - Battery Basics for Mods.)
  
  
  
• Ohm's Law Calculator (Voltage = always use 4.2 volts. Resistance = your coil's ohm measurement. Current = the amps that the coil will draw from your battery.)
  
  
  
• Your coil's draw in current (amps) should not exceed the battery's amp limit; leave a wide margin of safety.

 

[OBDave]

Thanks all for the responses!

So, first I'm now thinking of trying the RBA on the Vamo V2 that I also have coming and just setting the power by wattage- good idea, MamaTried. And I'm nowhere near sub-ohming, I'm thinking I'd like to have at least a couple months' experience and feel comfortable with my materials before I even try. Likewise with the mech. I'm also going to pick up a multimeter from Harbor Freight or something - seems like I should be able to get a decent one for $10-15.

But supposing I do try to use the mech, if I figure a max 4.2 volt charge and a 1.5 ohm coil, Baditude's chart (thanks, bookmarked!) tells me I'll be generating 11.76 watts and drawing 2.8 amps off the battery - if my battery is rated for 10 amps and I want to build in my own 30% safety buffer as Bshollow suggests, then I should be well within my safe limit of 7 amps. Even if I were to do a sequential dual with two 1.5 ohm wraps (which would be 0.75 ohm combined, I believe, and well beyond what I'm looking to start with), I'd only be drawing 5.6 amps and generating over 23 watts of power, which sounds like a ton. Am I getting all this right?