Super sub ohm build

[guitarfanatic20]

Hello everyone,
I recently made myself some 24g kanthal claptons wrapped with 34g kanthal. I usually do 5 wraps around a 3mm diameter and dual coils come out to be around 0.25. I have an IPV5 200 watt mod and the ramp up time for the coils is at least 2-3 seconds before it reaches up to temp. I tried doing a staged heating coil with 5 wraps of Clapton wire and 23g kanthal wrapped in between the Clapton wraps. The build came out to be 0.12 ohms with a dual coil and I feel like that is way too low even though there was hardly any ramp up time with the staged coil. Is this build way too low to be fired safely? My mod fires it that low and I am using Samsung 25r batteries in what I believe is in a series with an IPV5. Can I safely use it or should I scrap the whole thing? The batteries did not get warm the whole time I was firing the coils.

 

[guitarfanatic20]

From what I calculated in steam engine, I would withdraw anywhere from 27-30 amps with the wattage I normally use.

 

[SLIPPY_EEL]

I understand that regulated mod's adjust the voltage to keep the power running at the set level.
I don't know if the chip in a regulated mod can tell how many amps can be safely pulled from the battery, probably not, But running a 0.12ohm build on a regulated series mod to get 200w would give you 4.9v and 40A, your Samsung 25r is rated to 20A so you are pulling twice as much power as you should be, this is as much as i understand although there may be something i've missed and there may be some kind of hocus pocus going on with the chip to soften the punch, i'm unsure here so hopefully someone will chime in and let us know.

On a Mechanical dual series mod not a regulated as you have your voltage would be set to 8.4v and you would need a coil build of around 0.35ohm to get to your desired 200w but you would still be over your amp limit and be at 24A.


IMO if you had a good mechanical dual parallel mod you would most probably get more run time and be safer as regards the amp pull as the batteries divide the load, although you would need to be running even more into subohm to reach the 200w target.
0.09ohm build
4.2v
47A
196w
You could use two LG HB6 which would give you a total of 60A but you would get very little run time!

Probably best to stick above 0.15ohm, use Vtc5 in parallel and find a build that works at this range.

 

[KenD]

I understand that regulated mod's adjust the voltage to keep the power running at the set level.
I don't know if the chip in a regulated mod can tell how many amps can be safely pulled from the battery, probably not, But running a 0.12ohm build on a regulated series mod to get 200w would give you 4.9v and 40A, your Samsung 25r is rated to 20A so you are pulling twice as much power as you should be, this is as much as i understand although there may be something i've missed and there may be some kind of hocus pocus going on with the chip to soften the punch, i'm unsure here so hopefully someone will chime in and let us know.

On a Mechanical dual series mod not a regulated as you have your voltage would be set to 8.4v and you would need a coil build of around 0.35ohm to get to your desired 200w but you would still be over your amp limit and be at 24A.


IMO if you had a good mechanical dual parallel mod you would most probably get more run time and be safer as regards the amp pull as the batteries divide the load, although you would need to be running even more into subohm to reach the 200w target.
0.09ohm build
4.2v
47A
196w
You could use two LG HB6 which would give you a total of 60A but you would get very little run time!

Probably best to stick above 0.15ohm, use Vtc5 in parallel and find a build that works at this range.

Resistance doesn't factor in to the amp draw on a vw mod. 200w is about 31 amps per battery in a (series or parallel) two-battery mod (cutoff at 3.2v, not accounting for chip efficiency), no matter whether the coil is .1 or 1.0Ω (assuming that the mod can buck/boost to the required voltages). But 31 amps is too much for the Samsung 25r, or any battery. 200w is simply too much for two-battery mods. With 20-amp batteries I wouldn't do more than 60w per battery, so 120w maximum with a two-battery mod.

Sent from my M7_PLUS using Tapatalk

 

[SLIPPY_EEL]

Resistance doesn't factor in to the amp draw on a vw mod. 200w is about 31 amps per battery in a (series or parallel) two-battery mod (cutoff at 3.2v, not accounting for chip efficiency), no matter whether the coil is .1 or 1.0Ω (assuming that the mod can buck/boost to the required voltages). But 31 amps is too much for the Samsung 25r, or any battery. 200w is simply too much for two-battery mods. With 20-amp batteries I wouldn't do more than 60w per battery, so 120w maximum with a two-battery mod.

Sent from my M7_PLUS using Tapatalk

Going through the figures in Steam Engine main page a Parallel mod with a build of say 0.088ohm / 200.45w = 47.73A which is about 23-24A per battery. not 31A.

For his regulated mod to hit 200w with a 0.12ohm coil you would presume it would set itself to 4.9v which would give you 40A, not 31A.

Maybe i'm missing what your trying to get at but neither the parallel or series would be at 31A and they definitely wouldn't be running the same amounts of Amps. to hit 200w.

 

[Verb]

Going through the figures in Steam Engine main page a Parallel mod with a build of say 0.088ohm / 200.45w = 47.73A which is about 23-24A per battery. not 31A.

For his regulated mod to hit 200w with a 0.12ohm coil you would presume it would set itself to 4.9v which would give you 40A, not 31A.

Maybe i'm missing what your trying to get at but neither the parallel or series would be at 31A and they definitely wouldn't be running the same amounts of Amps. to hit 200w.

Current=Power/voltage

Max Current occurs in a regulated mod when the battery is at its lowest voltage. If the regulated mod cuts off at 3.2V, 200W/3.2V=62.5A, cut in half with a parallel arrangement yields 31.25A.

For a series arrangement, a mod usually shuts down at 6.4V. 200W/6.4V=31.25A


Resistance is not a factor other than impacting the efficiency. On steam engine you need to select regulated and regulated power (VW). I assume you had it in regulated voltage (VV).

 

[SLIPPY_EEL]

Current=Power/voltage

Max Current occurs in a regulated mod when the battery is at its lowest voltage. If the regulated mod cuts off at 3.2V, 200W/3.2V=62.5A, cut in half with a parallel arrangement yields 31.25A.

For a series arrangement, a mod usually shuts down at 6.4V. 200W/6.4V=31.25A


Resistance is not a factor other than impacting the efficiency. On steam engine you need to select regulated and variable power. I assume you had it in variable voltage mode.

Ah right!.. i get it now .....i hold my hands up to making a booboo! i should really know this simple stuff so as i can help others like we do, no excuse really other than i mainly use Parallel mech mods and use regulated at times but i only plug and play them

 

[Matty316]

To work out the amp draw for a regulated device using wattage mode and also take into account mod efficacy you can use this equation.

I = amps
P = watts used
V = battery voltage
M = mod efficiency percentage

Note:
1. If using a dual series battery mod the battery voltage is doubled.
2. As battery voltage drops the amp draw increases so it's best to calculate from your mods cut off point (so if it cuts at 3.2v in a dual series battery mod you times that by 2 so it would be 6.4v).

 

[SLIPPY_EEL]

How can you tell if your regulated is series or parallel?

 

[Boden]

How can you tell if your regulated is series or parallel?

Generally it's series if one slot is positive up and one is positive down.

The basic formula is the same for both.
(Watts/cutoff Voltage) + 10% = Amp draw.
Or
(Watts + 10% Watts)/cutoff voltage = Amp draw.

So 200W / 3.2V = 62.5A + 10% for board losses = 62.5 + 6.25 = 68.75A

Divide that between two cells you get 34.37A draw per cell.

Divide between three cells in parallel you get 22.9A
---------
For two cell series 200W/6.4V = 31.25A + 10% = 34.37A

For three cell series 200W/9.6V = 20.83 +2.08 = 22.9A
---------

It's easier for some to just add the 10% to the watts.

Eg. 200 + 10% of 200 = 220W/ 9.6V =22.9A

 

[SLIPPY_EEL]

Generally it's series if one slot is positive up and one is positive down.

The basic formula is the same for both.
(Watts/cutoff Voltage) + 10% = Amp draw.
Or
(Watts + 10% Watts)/cutoff voltage = Amp draw.

So 200W / 3.2V = 62.5A + 10% for board losses = 62.5 + 6.25 = 68.75A

Divide that between two cells you get 34.37A draw per cell.

Divide between three cells in parallel you get 22.9A
---------
For two cell series 200W/6.4V = 31.25A + 10% = 34.37A

For three cell series 200W/9.6V = 20.83 +2.08 = 22.9A
---------

It's easier for some to just add the 10% to the watts.

Eg. 200 + 10% of 200 = 220W/ 9.6V =22.9A

Okay thanks, i opened up a thread straight after posting my question How can you tell which it is?