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I was checking the calculator and got this..
- Thread starter vapeju
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shynsly
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it does not look right...try this calculator!
http://www.steam-engine.org/ohm.asp
Also i would get a name brand battery like a samsung or LG...
Good Luck!!!
http://www.steam-engine.org/ohm.asp
Also i would get a name brand battery like a samsung or LG...
Good Luck!!!
On a mech mod, you regulate the power with your coil build. Increasing the resistance will lower the power. This can be tricky, when not using the proper wire, e. g. if the wire is too thick, the ramp up time for the coil(s) could get longer. Therefore, plan your build using http://www.steam-engine.org/coil.asp as a guideline. Pay attention to heat flux and heat capacity (Note: you can play with the wattage next to the heat flux as well). Click the "How it works" in the bottom left of the page.
Your wattage will be different depending on if you are running in series or parallel you are mising one important variable 2x18650 begs this question... make sense? if you are running parallel it will be 4.2v if you are running series then it will be 8.4 with freshly charged batteries..
In addition, when running the batteries in parallel, you double the Ampere (A).
Get rid of those batteries before you blow a hole in the roof of your mouth. Buy a brand name like Samsung 25r or LG HE4
vapeju
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I am still waiting for them in the mail. Dont worry Im not actually using it yet. Just planning a build
Good deal.
Any battery with the word "fire" in it, is a piece of shit, don't use them. Although they may be good for flashlights.
There are several reputable places to buy brand names. Proper batteries are arguably the most important link to the whole vape experience.
With series, you double the voltage. Which means to don't have to build super duper sub ohm coils to get the same effect. For example, you can build .6ohm coils, which will run at 14amps (well within the safety margins of a 20amp battery), and still push 117watts.
..edited to say 14amps instead of 17
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Two batteries in parallel and a 0.15 coil at full charge is about 4V, 106W, 13.3A per battery
Completely empty would be 3V which would give 68W, 10.7A per battery
thejman
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Hi all, hope you don't mind if I join in and ask a few questions as I am trying to learn ohm's law. I understand the battery safety but trying to know more.
.15 coil at full charge is about 4.2v 120w and 28a at fully charged on steam engine.
Would this change depending if I had 1 or 2 batteries in a mod? I didn't think so but some information on previous replies kind of had me thinking. Not sure if I'm even making sense xD
.15 coil at full charge is about 4.2v 120w and 28a at fully charged on steam engine.
Would this change depending if I had 1 or 2 batteries in a mod? I didn't think so but some information on previous replies kind of had me thinking. Not sure if I'm even making sense xD
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Those things don't change if you put them in parallel but what does change when you have two batteries is the amps and watts get split between the batteries. So it's still 4.2V 28A, but each battery provides 4.2V 14A since they're in parallel.
As an aside, this is part of why you always want to pair batteries because then it splits the amps equally. If one has higher internal resistance from being older or a different type of battery then the amps will be split but not equally so one could be doing the majority of the work.
That's assuming they're parallel (positive connected to positive), if you have them in series (negative of one to positive of the other) - then you have 8.4V so your watts and amps skyrocket, and in addition you have nothing in parallel so the amps don't get split between the batteries. Note this is only true for mechanical mods, in a regulated mod series vs. parallel doesn't matter as long as the chip is doing its job.
Make sense?
thejman
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Yes Thank you very much!
Did you mean ea battery if dual gives 2.1v in parallel when fully charged? Just making sure if it was a typo.
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Okay got it so for series the volts are added together. I don't really plan on going the series direction but just to get a wider understanding are the watts and amps also split between the batteries or is that just for parallel.
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Lastly theoritcally speaking lets say I have a dual 18650 parallel mech mod.. for say like an osmium.
2 fully charged LG 20A batteries it would be safe as long as it's under 20A right?
for example: .3 ohm which would give me 7A and 2.1V each( powering at 58.8w. )
Do I understand it right? I've been trying to learn for quite a while as I am a slow learner; apologies and please bare with me.
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Isn't the reason most regulated dual battery mods are series because of the higher voltage potential?
Certainly.
Oh my...
You've got the relationship between things confused. Voltage is like pressure. Amperage is like volume. Ohm is a unit of resistance. It is the amount of voltage applied to a given resistance that results in an amount of current flow.
If voltage is constant and resistance drops: Current flow increases. If resistance is constant and voltage increases: Current flow increases.
That .15Ω coil is a .15Ω coil, regardless of the battery charge. If your battery, at full charge, is 4.2V, then (and here's Ohm's law at work): I = V/R, so I = 4.2/0.15, so I = 28A.
As to the wattage? Watts = Amps times Volts. In this case: W = 28 * 4.2 or 118W.
Well, that depends. If you put 'em in series: Yes. Because then you'll double the voltage. (236W for vaping, tho? Srsly?) If you put them in parallel: No. In that case you'd only be increasing current-supply capacity. The amount of current that would actually flow is subject to Ohm's Law, as detailed above.
Hope this helps
thejman
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Certainly.
Oh my...
You've got the relationship between things confused. Voltage is like pressure. Amperage is like volume. Ohm is a unit of resistance. It is the amount of voltage applied to a given resistance that results in an amount of current flow.
If voltage is constant and resistance drops: Current flow increases. If resistance is constant and voltage increases: Current flow increases.
That .15Ω coil is a .15Ω coil, regardless of the battery charge. If your battery, at full charge, is 4.2V, then (and here's Ohm's law at work): I = V/R, so I = 4.2/0.15, so I = 28A.
As to the wattage? Watts = Amps times Volts. In this case: W = 28 * 4.2 or 118W.
Well, that depends. If you put 'em in series: Yes. Because then you'll double the voltage. (236W for vaping, tho? Srsly?) If you put them in parallel: No. In that case you'd only be increasing current-supply capacity. The amount of current that would actually flow is subject to Ohm's Law, as detailed above.
Hope this helps
It does help a lot thank you.
Mind checking this for me ?
Lets say I have a dual 18650 parallel mech mod.. for say like an osmium clone or something
2 fully charged 20A batteries it would be safe as long as it's under 20A right?
for example: .3 ohm which would give me 7A and 2.1V each( powering at 58.8w. )
No, it was not a typo. I meant 4.2V in parallel.
You're asking really good questions. Voltage and current are hard concepts to grasp.
Basically when you put batteries in parallel it doubles the amount of current that can come out, but voltage doesn't change. When you put them in series it doubles the amount of voltage but the current doesn't change.
So the theoretical maximum of two 4.2V 20A batteries in parallel is 4.2V and 40A, while the theoretical maximum of two 20A batteries in series is 8.4V and 20A. It's smart to leave some safety margin but I'm just talking in theory here.
So in your example, 0.3 ohm would give 7A and 4.2V for each battery. If you did 0.3 ohm with only one battery it would be 14A and 4.2V for that battery.
Another thing to remember is that they're 4.2V when fully charged, but lower voltage as you use them. So you should always do calculations for the voltage you take them out at as well as when they're full, and make sure both are good. If for example you take them out at 3.2V you should redo the calculations there. Of course once you do this for a while you realize that for mechs the one that matters is the full voltage (4.2V) since that's when the highest amps happens while for regulated devices they're most stressed at low voltage.
Hope that helps.
353 watts. Yes. Seriously. On a full charge in the Hammer that is.(236W for vaping, tho? Srsly?)
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thejman
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Thank you very much. I think I get it?
Please correct me if I'm wrong. So theoretically speaking, with dual 20A 18650s on a parallel mech mod, I can push it as far as 40A? Would it be relatively safe to test different resistances as long as I'm calculating under that 40A limit. Which I believe would be as low as .11 ohm firing just under 120W? I will be leaving a safety margin ofc.
I've watched plenty of videos and read many articles/tutorials but there's always a question or two left in my silly brain. Apologies for many questions.
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You're correct. Also remember, we use our batteries in a "pulse" fashion (3-5 second average) and batteries actually have higher amp ratings for pulse use. The 20 amp rating is a "continuous" rating. Meaning turn them on, and let them drain till dead. Noone Vapes that way.
thejman
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YES!!!! THANK YOU. I lost you there at the end. Are you telling me that it might even be a little more than 20A when vaping because it's not continuous? Or did I completely misunderstand you lol.
You're correct. But you must really know your batteries limitations. Be safe!
thejman
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WOOHOO! Everyoen thank you very very much! & OP sorry for intruding.
Do a little homework and you can find the pulse rating of your batteries.
thejman
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Yes I will! Do some companies include them in the details?
Eh, not usually. This thread of mine contains information from Samsung regarding pulse ratings of IMR 18650 25Rs
thejman
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Mind linking your thread?
http://vapingunderground.com/threads/samsung-imr18650-25r5-green-wrap-specs.138621/ sorry got sidetracked.
tesiyi battery
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Hello,Jon@LiionWholesale, do you received our tesiyi 40A batteries? She said she have sent the batteries 5 days ago.
You find more details on the batteries at http://liionwholesale.com as you look at specific batteries.
@Jon@LiionWholesale send her/him a PM.
So who's batteries are you rewrapping and why are you not using continuous discharge ratings? More Chinese battery bullshit.
One fresh 18650 battery on a .15 ohm load maybe ~3.8 volts when you press the button. 2 in parallel you wont have as much drop, maybe close to 4.0 volts...
tesiyi battery
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our tesiyi battery can be continuous in 40A for a few minutes,if you have not testing our battery. please take your last word！
What a joke.our tesiyi battery can be continuous in 40A for a few minutes,if you have not testing our battery. please take your last word！
iSubOhm
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You took the words right out of my mouth. Samsung, LG and Efest as a last resort. These will be your go to batteries. I wouldn't even mess around and put any battery like that in my mod.
iSubOhm
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I would check on Mooch's battery tests. He has a lot of popular batteries listed there.
http://vapingunderground.com/threads/moochs-battery-tests.132451/
tesiyi battery
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He post on ECF, not here. our brand is TESIYI
iSubOhm
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Yeah not very relevant to my post, but thanks? And I'll stick with my Samsung 25r5's
tesiyi battery
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Hi Jeremy,
I finished testing the four cells and I rate the Tesiyi 40A/2600 cell at 25A/2300mAh. They delivered about 17% more capacity than the Samsung 25R at 20A down to 3.2V. All four cells were very close to each other in performance, which is good.
Mooch's email to me.
So I was right, they're over spec'ed. Surprise, surprise. You still never said who's cells you're rewrapping.
Realistically, with a decent battery, and a 0.15 ohm load you'd see around 91 watts fresh off the changer. How did I get this?
OK, to start ohms law, I need 2 values. We have the 0.15 ohm resistance. We cant use max amps, because that is max, not whats actually being used. We need to start with the "applied" voltage. Not the resting voltage. So when looking at discharge charts, most decent batteries when firing at 20 amps have around 3.8 volts for the first few seconds, and after that its downhill. In this case, we will end up using a bit more, so I'll knock off another .1 just for accuracy. So we have the 2nd number at a realistic 3.7 volts. Using these numbers we get ~91 watts. The current is around 24.7 amps. So we should be using a 30 amp battery. Can you get away with this with a 20 amp battery? Sure. But I wouldn't recommend it. Not all batteries are equal. Not even same make/model.
iSubOhm
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Can it be done with a 20 amp battery? Yes. Can it also cent and possibly explode if so? Yes. That's almost 5 amps over that batteries limit. I for one wouldn't even go that low with a 30 amp battery.. For safety reasons. Just get an unregulated box, people.. I have one and I hardly ever even go that low.. Utmost safety should be taken when building because really.. Why take the risk of losing not only your face, but your ability to vape again and the right to vape for others for that matter.
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