Coil Wrapping

[Kinghen]

Hello again guys, i had a quick question for you guys.

on the

http://www.steam-engine.org/coil.asp?s=dp&r=0.1&awg=20&id=3

coil wrapping calculator i ran across this line

"Total length of the resistance wires between coil and contact points."

im not sure what that means. may someone pleeeeease explain !


thanks in advance!

 

[Kinghen]

Does this look right fo a 3.7V 35a 3000mah 18650?

 

[State O' Flux]

It's highly unlikely that your battery has 35 amps continuous current discharge... few can even make 30A.
In fact, it may go into an unsafe temperature condition with a 35 amp pulse discharge... which is not what you're drawing with that resistance anyway.

Your build, assuming you're using a mech... is dangerous. At 4.2V, your 0.1Ω build will require a discharge of 42 amps and 176 watts.
The likelihood of exceeding safe battery temperatures, and approaching thermal runaway, is very real.

You clearly don't know how things work, and may injure yourself, or worse, a loved one. You can either educate yourself (click my sigline Steam Engine and Mech mod user guides below, and start reading)... or buy a high watt regulated mod, with lots of built in safety features, and forget about mechs.

 

[Neunerball]

Hello again guys, i had a quick question for you guys.

on the

http://www.steam-engine.org/coil.asp?s=dp&r=0.1&awg=20&id=3

coil wrapping calculator i ran across this line

"Total length of the resistance wires between coil and contact points."

im not sure what that means. may someone pleeeeease explain !


thanks in advance!

First, I do agree with @State O' Flux, regarding a 0.1 Ohm build. However, in order to answer the question about "Total length of the resistance wires between coil and contact points". This input field is asking for the length of the wire of both legs from the coil to the posts. So, if the legs on both sides of the coil to the post measure 2mm each, you'd enter 4mm in that field. If it's just 1.5mm on each leg, you'd enter 3mm.
Be aware, that the Steam Engine is just a guideline for building your coil(s). Always utilize an Ohm meter, in order to verify your build hasn't a short, and does have the resistance you were trying to get accomplished, before putting it on your mod.

 

[Kinghen]

First, I do agree with @State O' Flux, regarding a 0.1 Ohm build. However, in order to answer the question about "Total length of the resistance wires between coil and contact points". This input field is asking for the length of the wire of both legs from the coil to the posts. So, if the legs on both sides of the coil to the post measure 2mm each, you'd enter 4mm in that field. If it's just 1.5mm on each leg, you'd enter 3mm.
Be aware, that the Steam Engine is just a guideline for building your coil(s). Always utilize an Ohm meter, in order to verify your build hasn't a short, and does have the resistance you were trying to get accomplished, before putting it on your mod.

Thanks , I briefly read up on it and I didn't know that the total amp output was diff from the max continuous output


Vape life

 

[State O' Flux]

Thanks , I briefly read up on it and I didn't know that the total amp output was diff from the max continuous output
Vape life

With mechs... the net resistance (and battery voltage - 4.2v is the standard, fully charged value most commonly used) is what determines amp/watt discharge. You use an Ohm's law calculator to arrive at the desired values.

 

[Kinghen]

Im not sure how to calculate the continuous discharge please let me know what im doing wrong.

im using a
MXJO IMR 18650
3000mAh
3.7v 35a

 

[State O' Flux]

Im not sure how to calculate the continuous discharge please let me know what im doing wrong.

im using a
MXJO IMR 18650
3000mAh
3.7v 35a

You use Ohm's law formulas, or a on-line OL calculator. There's one in the Steam Engine group of calculators. The Locust calculator is simple, and includes an Ohm's law formula wheel directly below it.

You can use the peak charged voltage for an 18000 series battery, which is 4.2V... or a little less, because the peak drops off pretty quickly with a heavy discharge. I tend to use 4.0V as a slightly more realistic value with mech batteries and low, sub-ohm net resistances.

Without independent regulation, a battery will discharge wattage/amperage at a rate determined by net resistance and voltage.

• For wattage ("Power") the formula is: V² ÷ Ω = P.
• For amperage ("Current") the formula is: V ÷ Ω = C.

The calculated wattage doesn't care about your wire gauge or coils in parallel count... just the net resistance and battery voltage.

Heat flux and capacity do care about the wire gauge (AKA wire surface area & mass), coils in parallel count and net resistance, and is directly affected by them, both together and independently. Heat flux is the coil(s) radiant heat, expressed in milliwatts per millimeter of coil surface area... squared. For our purposes... it's simply how warm you perceive your vape to be.

Although Mooch hasn't tested a 3K mAh MXJO yet, considering the tested MXJO 2.5K mAh is, in reality closer to a 20A continuous... 20 amps is what you have to work with before you start pushing battery temperatures into an unsafe range.

 

[Kinghen]

whats wrong with this picture?

 

[Bean8379]

I have an efest 1600mah, rated at 30A, but this battery has been tested and drops off around 20A. For safety sake, I do not even get close to 20A. I'm running a single .84ohm coil in my rda, which comes out to 4.76A @ 4.0v, and dual coils in my orchid tank which are .69ohms and come out to 5.8A @ 4.0v. I researched my battery's testing info before I even started using my mech. The lower the resistance, the higher the amps. 0.2ohms at 4.0v is exactly 20 amps. Even with a regulated mod, you should know your ohms because most regulated mods won't fire below a certain resistance, so building lower than that limit would be pointless.

 

[Slurp812]

If you have a 0.10 coil, you be lucky if you have ~3.6 volts on the thing when you press the button.

 

[Kinghen]

How low can you go when building for a 18650 ?


Vape life

 

[Bean8379]

How low can you go when building for a 18650 ?


Vape life

It depends what amps the battery can handle. You also need to research your battery to see if it has been tested. Sometimes what it says on the label isn't always accurate. There are websites that have battery testing info. Some batteries have not been tested and I personally so not recommend using a battery that hasn't. Perfect example, my battery is rated for 30A, but when I looked for testing info, I found that the battery dropped off around 20A in testing. The reason your battery's true amp limit is very important is this. The lower the resistance, the higher the amps. Exceed your battery's amp limit, and well, kaboom! No two 18650 batteries are alike, so do your research.