Ohm's Law for dummies... meaning me.

[Papillon61]

Please let me see if I have understood correctly. With a regulated mod you can set the voltage and watts that you wish. With an unregulated mod the current, wattage and amps that you draw from the battery depends on the ohms on your coil/s, correct? Naturally, if you are firing a coil rated at ohms that your battery can't support or keep up with, you're in trouble - also correct?

If not please explain further. Thanks.

 

[Alien Traveler]

Correct.

 

[Jimi D.]

Ohm's law | Steam Engine | free vaping calculators

 

[Baditude]

Explain It To the Noob: Ohm's Law Calculators

Ohm's Law for Dummies (Vapers)

 

[Papillon61]

Thanks, yes my question was to make sure I understood correctly all that is written in the links you provided. I read, but then I have to check that i have actually understood what I read. Just reading and thinking you have understood without putting yourself to some sort of test could be pretty dangerous.

 

[Baditude]

This is why most veterans recommend a new vaper not use a mechanical mod before using a regulated mod. Because of a lack of experience and safety. A mechanical mod is basically just a battery holder with a fire button and 510 connector, with no electrical protection circuitry.

With a mechanical mod:

No protection circuitry. This is a big one for beginners. The user must always be aware of the signs of a short circuit which could cause the battery to vent into thermal runaway. Must have ventilation holes and a hot spring for a venting battery.

No built-in voltage or resistance meters.

No way to regulate the battery output. As the battery drains during use, the vapor will continually decline gradually. No way to adjust the vape experience except by changing the atomizer resistance.​

With a regulated mod:

The battery power to the atomizer is controlled (regulated) to stay the same throughout the battery charge, from a fully charged battery until fully discharged.​

The power can be adjusted to increase or decrease the voltage by the user, allowing the user to change their vaping experience.

Has built-in protective circuitry (microprocessor) against short circuits, atomizer shorts, accidentally putting battery in backwards, and over-heating.

Has built-in battery voltage and atomizer resistance meters to check battery status and the ohm of the coil.​

 

[bwh79]

Please let me see if I have understood correctly. With a regulated mod you can set the voltage and watts that you wish.

Almost. With a regulated mod, you set either wattage or voltage; the other will adjust accordingly, based on the attached resistance (atomizer). You can't set them both, independently of one another.

Amps = Volts / Ohms

Watts = Volts^2 / Ohms
... = Volts * Volts / Ohms
... = Volts * (Volts / Ohms)
... = Volts * (Amps)
... = Volts * Amps

Watts = Volts * Amps
Volts = Watts / Amps
Amps = Watts / Volts

...these are all different ways of saying the same thing, and there is nothing you can do to make these equations untrue. So if you change anything on one side of the equation, something has to change on the other side as well, to maintain the equivalency.

With a mechanical or unregulated mod, the danger comes in working your battery past its limits by drawing too high of a current (amp draw.) So in order to remain safe, you must know the maximum continuous discharge rate (CDR) of your battery (note: continuous discharge rate, not the "pulse" or "peak" discharge rate as that is a meaningless figure for our purposes) and select a resistance that will keep you well within that amp limit. Do all your calculations at 4.2v, as for a fully-charged battery.

In a regulated or variable mod, keep in mind that the amp draw is affected only by the power setting (and the charge state of the battery), and not by the attached resistance. This is because, no matter what the settings are, the battery itself is only ever outputting a single voltage (based on the charge state, 4.2v at full charge, and less as the battery begins to drain.) So if you're set for 50 watts, for example, and your battery is at 4v, then according to Amps = Watts/Volts, you are drawing 50/4 = 12.5 amps off the battery, regardless of whether you're pumping those 50 watts into a 2-ohm load or a 0.2. In this case, the device's internal circuitry should keep you protected but, just to be on the safe side, note that the amp draw is higher when the battery is depleted, not when it's fully charged as would be the case with a mechanical device, and so your safety calculations should be done assuming a lower voltage of around 3.2v, or whatever the cutoff is for your particular device.

 

[DanJiblets]

My kind of thread!