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battery safety question on regulated mod

I have a quick battery safety question. I have a segelei kaos spectrum with a tfv12 and a dual coil rba deck installed. I am running a .1 ohm build with 18 guage kanthal and vaping at 100w. My 2 batteries in the mod are LG HB2's which are 30 amp continuous discharge. My mod says its trying to pull 33 amps at this wattage to attain the vape. Am I safe? From what I have researched it seems that I am safe but I just want to absolutely make sure and not do something stupid.
 

meloserj

Member For 3 Years
Member For 2 Years
In regulated mods, this is the chip which decides what Voltage will be enough for your desired wattage. Also know that its "regulated" so you can't decide bout serial or parallel battery configuration. So as long as mod is firing up that 0.1 ohm, so you are safe :)
 

meloserj

Member For 3 Years
Member For 2 Years
18 gauge? Wow haha! I use 22 and most people say "really??" Lol
To be honest, I don't know how this dude is vaping on 18Ga. My lowest one was 20Ga and I was burning from mouth to a$$. Anyway everyone has its own style and important is that our motto which is "No Cigarette" :)
 

MikeDommy

Bronze Contributor
Member For 4 Years
To be honest, I don't know how this dude is vaping on 18Ga. My lowest one was 20Ga and I was burning from mouth to a$$. Anyway everyone has its own style and important is that our motto which is "No Cigarette" :)

I think you can BBQ ribs with 18g wire.
 

Mattp169

Platinum Contributor
Vape Media
Member For 5 Years
ACTUALLY regulated mods do not switch from series to parrallel . they do normally all run in series which means your amps are not combined ever so you have the amp of one battery in this case 30 amps
As your battery discharges your amp draw increases
the resistance of your coil is not calculated in determining amp draw of a regulated mod.

so at 100 watts at full charge of 8.4 volts you should be pulling about 12 amps
but that does not take into account the efficiency of the mod
so we will assume that it is at least 90% efficient
so divide 12/.9 and you get a little more then 13 amps

now

as your batter discharges
at 7v of battery power remaining and still assuming 90% efficiency you are up to almost 16 amp draw

at low voltage cutoff - which is different for every mod but we will use the lowest most go of 6v and you are pulling 18.5 amps

why your mod is saying 33 amps is anyone's guess, someone else here knows that answer

but even if it pulls 33 amps on 30 amp batteries for a few second pulls here and there you should be fine

regulated Variable wattage mods use WATTS LAW to calculate amp draw
which is watts/volts of the battery (not what the mod says) divided by mod efficiency ( which is usually at least 90% but some are higher like 95% etc)

mech mods and PWM mods use Ohms laws to calculate amp draw

WHY? because the circuitry of the regulated variable wattage mod is trying to maintain the WATTS and doing what every is necessary to the batteries to obtain it. SO you use WATT'S law not OHM'S
 

Mattp169

Platinum Contributor
Vape Media
Member For 5 Years
The mod displays output amps (i.e. the amps that the board outputs to the coils, not the amps that it draws from the batteries).
thanks that makes sense

what these "regulated" mods need is a setting for what batteries you are using and the logic built in to not tax the batteries.
 

David Wolf

Silver Contributor
Member For 2 Years
Member For 1 Year
ECF Refugee
You are operating in spec but near the maximum output current of 35A for your Kaos Spectrum, and at the very minimum of the resistance at 0.1 ohm. I don't know if that is safe or not since I don't know the reliability of that mod and what if any conservatism they have in the specs (hopefully some). I never get that close to the maximum of any mod, I vape at low power.

Your batteries are ok at that level though.
Carambrda is right about that 33 amps being output to the coil, not from the battery.
Power= I(squared) x R, thus I=SQRT(Power/R) = SQRT(100W/0.1ohm) = 31.6 Amps which is close to your display reading, thus confirming that this is the output current to your coil.
For battery current, we have to know if the batteries are in series (most mods are, but not all are). In the case of the Siegeli Kaos Spectrum the batteries are in series. The specs for your device state an input voltage range of 6.4 to 8.4V, that's 3.2V to 4.2V for each battery, with the batteries in series.

To determine current draw from the series batteries, use the lowest voltage of 6.4V, and typically an efficiency factor of 0.85 to 0.9 is alo assumed. I have started using 0.85 lately since a gentleman here on VU was using that and I found at least one mod at that efficiency (note: efficiency typically decreases below that at lower power levels).
And the power formula applied on the battery (input) side is as follows:
Power (setting value) = I x V / efficiency factor, thus I = Power / V / efficiency factor.
I = 100W / 6.4V / 0.85 = 18.3 Amps.
So you are well below your HG LB 18650 batteries continuous rating of 30A.

References:
Kaos Spectrum specs, http://www.sigelei.com/product/index.html?id=19

Disclaimer

I am not a vaping expert, but I do play an electrical/controls engineer on TV.
 
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Carambrda

Platinum Contributor
ECF Refugee
Member For 5 Years
thanks that makes sense

what these "regulated" mods need is a setting for what batteries you are using and the logic built in to not tax the batteries.
ArcticFox firmware offers a few small steps in that direction, but not every mod is compatible with it, and it's still up to the user to remember to set it all up right. Either way... I like that it can be used to set user-defined safety values like "Power Output" and "Puff Cut-Off" (under the Advanced tab in the NToolbox software) as well as "Cutoff" → "Volts" (at the bottom of the Discharge Profile window that pops up after you click on the Edit button next to "Battery Model"─the discharge graph itself is pretty much useless).
 

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