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How to calculate coil resistance and wattage

Hello,
Im not very experienced with building coil and calculating everything, therefore im asking here for guidance, so im gonna use this coil with 0.05 resistance and i got 2 batteries(40A pulse and 32A continuous) and 3.7V batt, thats almost everything i need to know, but im curious what watt im gonna get out from that, im familiar with ohm’s law but im not 100% i will get it right and i dont wanna find that out the hard way(damaged mod/battery or burt coil) so can someone show me what calculations to use and how to put all this info togheter to make RDAs with the right resistance and right watt (if there are already a thread about this please link it to me bcus i didnt fint it)
 

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KingPin!

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Current draw is what you are intersted in for the pulse...what batteries are you using?

I = V \ R = current draw
Power (wattage) = V x V / R

This site will help you a lot :)
http://www.steam-engine.org/wirewiz.html

Also that build you posted above (2x26g with 39g wrap NI80 ...3mm ID) you’ll want 5 wraps to be just under 0.3ohms, or 6 wraps to take you just over 0.3ohms. Bear in mind this is for a single coil!

If you run the pulse 24 have 2 coils it will halve this resistance so you’ll be better going thinner gauge 28g cores keep the number of wraps down that way to say 7 wraps (2 x 28 with 39g NI80 and 3mm ID)
 
Last edited:
Current draw is what you are intersted in for the pulse...what batteries are you using?

I = V \ R = current draw
Power (wattage) = V x V / R

This site will help you a lot :)
http://www.steam-engine.org/wirewiz.html

Also that build you posted above (2x26g with 39g wrap NI80 ...3mm ID) you’ll want 5 wraps to be just under 0.3ohms, or 6 wraps to take you just over 0.3ohms. Bear in mind this is for a single coil!

If you run the pulse 24 have 2 coils it will halve this resistance so you’ll be better going thinner gauge 28g cores keep the number of wraps down that way to say 7 wraps (2 x 28 with 39g NI80 and 3mm ID)

Its for a dubbel coil, and i got 2x Basen IMR 3100mah 40A pulse and 32A continuously draw, its already a prebuild coil so how do i change the wraps?
 

r055co

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Its for a dubbel coil, and i got 2x Basen IMR 3100mah 40A pulse and 32A continuously draw, its already a prebuild coil so how do i change the wraps?
First off there are no 32a batteries period, the Basens are rewraps and grossly exaggerated ratings from Basen. Mooch tested them and they're actually only 10a batteries.

To add or subtract wraps on pre-made coils, well either wrap another wrap or unwind a wrap.

Sent from my HTC 10 using Tapatalk
 

KingPin!

In my defence, I was left unsupervised ^^
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Its for a dubbel coil, and i got 2x Basen IMR 3100mah 40A pulse and 32A continuously draw, its already a prebuild coil so how do i change the wraps?

Buy bigger diameter and tighten them on the 3 or 2.5mm drill bit or coil jig ....you’ll be able to get some extra wraps that way

Otherwise buy some coils that meet your resistance requirements just remember to halve stated single coil resistance :)

Do you have a resistance reader or regulated mod to check resistance first before putting RDA straight onto a mech?
 
Buy bigger diameter and tighten them on the 3 or 2.5mm drill bit or coil jig ....you’ll be able to get some extra wraps that way

Otherwise buy some coils that meet your resistance requirements just remember to halve stated single coil resistance :)

Do you have a resistance reader or regulated mod to check resistance first before putting RDA straight onto a mech?
The mod im gonna use with this RDA is Smok MAG so i got a regulated mod so i can check the resistance, it was a kit and a total of 48 different coils , so thats no problem to use another one with better resistance to fit the RDA and battery, what batteries can i buy to get higher amp?
 

KingPin!

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img_1528-jpg.705509
 

Mattp169

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ok quick lessons on battery safety
1. amp draw is what is important. unless you have sony,lg,samsung batteries. everything printed on your label is an exagerration to out right lie. use the charts people posted.
2. exceeding the amp limits of your battery is what causes thermal runaway, venting and is what is dangerous
3. there are basically three types of mods and depending on what you have determines how you figure stuff out
a. VW vaiable wattage
b. VV variable voltage
c. mech mod

A variable wattage mod you determine the amp draw by taking your watt setting dividing byu the current volts(not whats printed on the label of 3.7) THEN DIVIDING THAT BY ABOUT 90% BECAUSE THERE IS SOME VOLTAGE SAG THROUGH THE BUTTON WIRES AND OTHER ELECTRONICAL PARTS.

so you amp draw actually increases as the battery drains

a variable voltage and mech mod basically work by ohms law to determine amp draw

4. you do not add amps in most mods - if you have 2 batteries that are both 20 amp then you only have 20 amp to use not 40. UNLESS your mod specifically says it is a parrallel mod.

So to your specific situation
YOUR BATTERIES ARE JUNK get some lg sony or smasung from a reputable supplier such as illum.com,lionwholesale.com ro a few others. lg hg2 smasong 30q sony vtc5s etc do some research

since they are about 10 amp batteries you should not go much above 60 watts as your setting until you get better batteries that are at least 20 amp

how did i get this 60 watt number, like I said above for a variable wattage mod which is what you have
60watts divided by the lowest voltage your batteries should go which is 3 volts each and since there are 2 its 6 volts the divide by 90% for efficiency of the electronical parts and you get 11.11 whic is close enough to 10 amps and since your mod will stop firing after 10 seconds you shouldnt be pushing those batteries too much
 
ok quick lessons on battery safety
1. amp draw is what is important. unless you have sony,lg,samsung batteries. everything printed on your label is an exagerration to out right lie. use the charts people posted.
2. exceeding the amp limits of your battery is what causes thermal runaway, venting and is what is dangerous
3. there are basically three types of mods and depending on what you have determines how you figure stuff out
a. VW vaiable wattage
b. VV variable voltage
c. mech mod

A variable wattage mod you determine the amp draw by taking your watt setting dividing byu the current volts(not whats printed on the label of 3.7) THEN DIVIDING THAT BY ABOUT 90% BECAUSE THERE IS SOME VOLTAGE SAG THROUGH THE BUTTON WIRES AND OTHER ELECTRONICAL PARTS.

so you amp draw actually increases as the battery drains

a variable voltage and mech mod basically work by ohms law to determine amp draw

4. you do not add amps in most mods - if you have 2 batteries that are both 20 amp then you only have 20 amp to use not 40. UNLESS your mod specifically says it is a parrallel mod.

So to your specific situation
YOUR BATTERIES ARE JUNK get some lg sony or smasung from a reputable supplier such as illum.com,lionwholesale.com ro a few others. lg hg2 smasong 30q sony vtc5s etc do some research

since they are about 10 amp batteries you should not go much above 60 watts as your setting until you get better batteries that are at least 20 amp

how did i get this 60 watt number, like I said above for a variable wattage mod which is what you have
60watts divided by the lowest voltage your batteries should go which is 3 volts each and since there are 2 its 6 volts the divide by 90% for efficiency of the electronical parts and you get 11.11 whic is close enough to 10 amps and since your mod will stop firing after 10 seconds you shouldnt be pushing those batteries too much
Very helpfull, i do got some sony vtc5 2600mah 30A batteries too, but i thought imr was better untill you guys gave me the research links about them haha
 

r055co

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Member For 4 Years
Very helpfull, i do got some sony vtc5 2600mah 30A batteries too, but i thought imr was better untill you guys gave me the research links about them haha
Sony VTC5 are NOT 30a batteries, they're 20a, please review Mooch's chart.

Sent from my HTC 10 using Tapatalk
 

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