Need help to grasp current (Amps)

[Vaping_Racoon]

Hi guys,

so I'm looking at my calculator and I'm wondering about how the current works.

Let's say I have a Dual Parallel 0.2 ohms build, the calculator says:

Based on 3.7[V] - Current 18.5 [A] - Power 68.5 [W]

So.. if I have 2 batteries rated at 20 Amps, I should be safe if the current drawn is
18.5 [A] ?

What happens if a build goes over 20 [A] ?

lol, thanks for helping me understand.

 

[Stinkytofus]

Steam Engine main page

 

[Vaping_Racoon]

Thanks but I get lost in ohm's law, I need someone to vulgarize it's effects for me.

 

[fenderstrat]

we would need more info to correctly answer.Is this a mech mod or regulated and, 2 batts wired series or parellel

 

[Vaping_Racoon]

Regulated and Series.

 

[inspects]

You should really start familarizing yourself with Coil wrapping Type in everything you posted, and read what the outcome is.

Then do the same here Battery drain

 

[fenderstrat]

ok ,in a regulated mod the build means NOTHING,the mod does what it need to to fire as long as the ohms are within the firing limits of the device its good.since you are running 2 batts in series you can use 7.4V as an average V.Take whatever watts you set your device at and divide by the V and this gives you an estimated AMP draw.Now there are variables like device efficiency and such but you can get an idea
for example if you set a device to 50W 50/7.4V =6.75Amps
most guys use the min volts to get what your max amp draw will be so using that 50watts/6.4(3.2V per batt)=7.4amps

 

[Vaping_Racoon]

Wow, now I understand lol

 

[Vaping_Racoon]

I was under the false idea that low builds we're dangerous.

 

[fenderstrat]

if you want to start really getting precise you can assume a 90% efficiency and use that to get a closer idea to what you are drawing

 

[beckdg]

ok ,in a regulated mod the build means NOTHING,the mod does what it need to to fire as long as the ohms are within the firing limits of the device its good.since you are running 2 batts in series you can use 7.4V as an average V.Take whatever watts you set your device at and divide by the V and this gives you an estimated AMP draw.Now there are variables like device efficiency and such but you can get an idea
for example if you set a device to 50W 50/7.4V =6.75Amps
most guys use the min volts to get what your max amp draw will be so using that 50watts/6.4(3.2V per batt)=7.4amps

Exactly

But be sure to always use 6.4 to 6.0 volts and your wattage setting to calculate your max amps.

The device is going to pull what it needs from the battery no matter the charge state, so the highest current will be drawn just before the batteries capacity is depleted.

This will keep you within the limits of your batteries.

Tapatyped

 

[fenderstrat]

low builds ARE very dangerous on a MECH mod as there is no control and a battery can be taxed till it vents.A reg mod simply wont fire
I dont know of any recent regulated mod that will let you do dmage to the batts.there are numerous protections in place.
Yes I'm sure someone could do it but under normal vaping conditions regulated mods are pretty safe. just remember Watts div by Volts = Amps you can multply by .9 if you want but you get the idea

 

[MMcQ]

That is some serious magic going on in these regulated boxes as according to that theory one should be able to put two 10 amps panny's in there and still get up to 50 watts. My kbox 120 says to only use 30 amp batteries (only got 20's) but i never go below 1.1 ohms and 20 watts so i'm just gonna risk it at this point. Thoughts?

 

[bwh79]

Regulated and Series.

Amp draw on a regulated device is related only to the wattage setting and remaining battery voltage, with the ideal formula:

Amps = Watts / Volts

You can then divide that result by the device's efficiency, or just use 90% (.9) if you aren't sure, for a total draw of:

Amps = (Watts/Volts) / .9

Note that atomizer resistance does not play a part in this equation.

Amp draw will be highest when the batteries are at their lowest charge, so when doing safety calculations you should use your device's low-voltage cutoff point, or if you don't know that value, you can use 3.2v per battery as a rough estimate. Batteries wired in series add their voltages together, so for a dual-battery device you're looking at 6.4v cutoff.

It's a good idea to leave yourself a good margin for error of at least 20%, which means you would not want to push a 20A battery any harder than 16 amps. Plugging in all these numbers together, we are looking at:

16 = (Watts/6.4) / .9

Rearranging a little we get:

16 * .9 = Watts / 6.4
16 * .9 * 6.4 = Watts
... = 92.16

You should be good with those batteries up to 92.1 watts.

Check: 92.1 watts / 6.4 volts / .9 efficiency = 15.989 amps

Some people prefer to leave a larger safety margin, sometimes as high as 50%. Others will be more comfortable pushing the limits, and might go as high as 100 or 120 watts on those batteries, but I wouldn't recommend that until you have significantly more knowledge and experience.

 

[fenderstrat]

yes there is no reason you cant use a 10 amp battery if you are vaping at low wattages...also,its not a theory its science...its not something that I believe thats unproven W/V=A is the foundation of electrical work
the issue starts comming in with 75 watt devices that use 1 battery

 

[Topwater Elvis]

Even using a regulated power device you still must choose appropriate batteries for your intended power range.

There is no saftey / protection feature that prevents the use of the wrong chemistry or insufficient CDR battery(s).

30w / 3.2v = 9.37a
40w / 3.2v = 12.5a
A 10a cell aint gonna cut it in the above examples.
Safety conscience vapers leave a % of amps under any battery’s CDR as a safety margin/headroom.
Some folks 20%, others 50% under the CDR.

 

[fenderstrat]

ok now I'm really going to $#@# up the works.
all this talk about Amp draw uses the CDR and we usually pulse our mods the problem is there is almost no info on what a "pulse" is on an 18650..lol..but its safe to say the pulse rating is almost always higher than the CDR so if its a 20 amp cdr batt and you are pulsing 25 amps you should be ok...but that is something I dont recommend unless you are fully aware of all conditions and you do so fully at your own risk

 

[fenderstrat]

I am amazed.I think we are making progress on ECF.We have a battery/amps discussion we are several posts in and not one insane statement and BECKDG and myself agreed.Its a new day

 

[MMcQ]

Even using a regulated power device you still must choose appropriate batteries for your intended power range.

There is no saftey / protection feature that prevents the use of the wrong chemistry or insufficient CDR battery(s).

30w / 3.2v = 9.37a
40w / 3.2v = 12.5a
A 10a cell aint gonna cut it in the above examples.

OP was talking about a Series mod with 2 batt's. That's a single battery equation.

 

[Vaping_Racoon]

Okay.. I wonder why they're selling a 200W Box with 2 Batteries if you can possibly only get 90 Watts out of it..
Are they trying to kill people or what?