I have been hearing this recently. Can anybody explain to me what it means? Why is it so significant?
The term "Voltage Drop"
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In a mechanical mod you are dealing with the straight voltage off of a battery. The parts that make up the pathway of the electrical circuit in a mod (the internals of the battery, the firing pin, the 510 connection) have varying amounts of electrical resistance.
In a perfect setting your coil would see 4.2V of straight voltage off of a freshly charged battery, but because of the resistance of the various parts I described, it is going to see less. This is the "voltage drop."
The lower the voltage drop, the more efficient/better performing the mod is.
In a perfect setting your coil would see 4.2V of straight voltage off of a freshly charged battery, but because of the resistance of the various parts I described, it is going to see less. This is the "voltage drop."
The lower the voltage drop, the more efficient/better performing the mod is.
Without getting too technical, it's the loss of voltage that happens when the voltage goes through a circuit.
And any connection can add resistance to the resistance of your coil.
In ecigs, the circuit is from the battery positive to the center post, from there to the center pin on the topper, then to one leg of the coil, through the coil and out the other leg to the outside of the topper base, then to the PV case and finally back to the negative end of the battery through the spring.
Since it's what's called a series circuit, each resistance, no matter how small, will "subtract" some of the applied voltage - the total voltage in a series circuit is the sum of the voltage drops across each resistance.
An extreme example:
Let's say you have a 2 Ω coil and want to vape your flavor at 4 volts. You set your VV device for 4 volts. But you have a bad connection somewhere that adds another 2 Ω to the circuit. The VV is going to "see" a total of 4 Ω, and "drop" 2 volts on the bad connection and only deliver the remaining 2 volts to the coil.
Now, as said, that's pretty extreme. Most times, the voltage drop across any contact resistance will be in the milli-Ω range, and may not be even noticeable. But keeping all contact surfaces clean is a must, to avoid high resistance problems.
And any connection can add resistance to the resistance of your coil.
In ecigs, the circuit is from the battery positive to the center post, from there to the center pin on the topper, then to one leg of the coil, through the coil and out the other leg to the outside of the topper base, then to the PV case and finally back to the negative end of the battery through the spring.
Since it's what's called a series circuit, each resistance, no matter how small, will "subtract" some of the applied voltage - the total voltage in a series circuit is the sum of the voltage drops across each resistance.
An extreme example:
Let's say you have a 2 Ω coil and want to vape your flavor at 4 volts. You set your VV device for 4 volts. But you have a bad connection somewhere that adds another 2 Ω to the circuit. The VV is going to "see" a total of 4 Ω, and "drop" 2 volts on the bad connection and only deliver the remaining 2 volts to the coil.
Now, as said, that's pretty extreme. Most times, the voltage drop across any contact resistance will be in the milli-Ω range, and may not be even noticeable. But keeping all contact surfaces clean is a must, to avoid high resistance problems.
There are a total of three "voltge drops" that we have to contend with.
#1 Voltage drop of the PV (no load), this is primarily caused by the metal used to make the PV.
#2 Voltage drop of the PV (under load) primarily caused by the quality of conections.
#3 Voltage drop cause by the atomizer resistance. The lower the resistance, the more the voltage drop.
example:
Same battery (4.18v) ... same atomizer (1 ohm)
PV made of brass with solid silver contacts
PV made of SS with brass contacts
So there is a difference of 0.12v going to the atomizer.
#1 Voltage drop of the PV (no load), this is primarily caused by the metal used to make the PV.
#2 Voltage drop of the PV (under load) primarily caused by the quality of conections.
#3 Voltage drop cause by the atomizer resistance. The lower the resistance, the more the voltage drop.
example:
Same battery (4.18v) ... same atomizer (1 ohm)
PV made of brass with solid silver contacts
PV made of SS with brass contacts
So there is a difference of 0.12v going to the atomizer.
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Backwards. A higher resistance will cause a greater voltage drop. A resistance of zero would have a voltage drop of zero.
Most confusing one is voltage drop under load. Found this post a while back; Voltage drop under load explained well.
It's all about the batteries
It's all about the batteries
The way that was explained in the original post was just a bit confusing. I think the point is that under load, a high resistance coil (low amp draw on battery) will not cause the battery voltage to go down nearly as much as using a low resistance (high amp draw) coil will. Think of your zero ohm example. That's a short. The battery voltage and thus the circuit voltage will go way down in this situation. Amps will go through the roof.
Battery voltage drop tends to be the most important (assuming no severe corrosion, dirt, or other problems--a reasonably clean mod, in other words).
Batteries have internal resistance and dissipate some energy as heat in the battery. That's why a battery undergoing a heavy drain gets hot.
If you look at battery discharge curves, the higher the discharge rate the lower the delivered voltage is at every point on the curve at identical capacity level. The remaining energy is being thrown away as heat.
High resistance through the rest of the circuit (low draw, in other words) tends to limit the importance of battery voltage drop, but our application's resistance tends to be low--3 or less. Battery resistance becomes significant when vaping.
Batteries have internal resistance and dissipate some energy as heat in the battery. That's why a battery undergoing a heavy drain gets hot.
If you look at battery discharge curves, the higher the discharge rate the lower the delivered voltage is at every point on the curve at identical capacity level. The remaining energy is being thrown away as heat.
High resistance through the rest of the circuit (low draw, in other words) tends to limit the importance of battery voltage drop, but our application's resistance tends to be low--3 or less. Battery resistance becomes significant when vaping.
Most good PV's (personal vaporizers) have some sort of circuitry built in that will boost the voltage of the battery to achieve what it's set ast. Lithium ion batteries are usually around 4.2v fresh off the charger. You can have your voltage set to higher than the actual battery voltage and it will boost the voltage to achieve your setting. Cheaper batteries like some egos will suffer from voltage drop as the battery is discharged. So you may start with 4.2v and it will gradually decrease as the battery is drained. This is another way the term "voltage drop" is used around here. Hope I explained it alright, and correctly.
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I see exactly what you are saying. It could be confusing indeed. Where is the voltage drop being measured? If the voltage drop is being measured across the internal resistance of the battery, the voltage drop would be huge if the load resistance is zero. If the voltage drop is measured across the load, a load resistance of zero would have voltage drop of zero.
Did the statement I responded to: "#3 Voltage drop cause by the atomizer resistance. The lower the resistance, the more the voltage drop." really mean: "#3 Voltage drop caused by the internal battery resistance. The lower the resistance of the atomizer, the more the voltage drop internal to the battery."??????? Confusing indeed. Since the voltage drop of the battery is not covered , that would be the 4th voltage drop in the circuit of a PV, battery, and atomizer in tj99959's explanation?
actually he is correct... the lower the resistance, the more amps are pulled thus a higher loss in voltage from the source
If the source has a higher internal resistance than the load.
There are a total of three "voltge drops" that we have to contend with.
#1 Voltage drop of the PV (no load), this is primarily caused by the metal used to make the PV.
#2 Voltage drop of the PV (under load) primarily caused by the quality of conections.
#3 Voltage drop cause by the atomizer resistance. The lower the resistance, the more the voltage drop.
example:
Same battery (4.18v) ... same atomizer (1 ohm)
PV made of brass with solid silver contacts
PV made of SS with brass contacts
So there is a difference of 0.12v going to the atomizer.
Thank you for the pictorial demonstration .. this is what I trying to explain in another thread (pet peeves) regarding a similar topic.
Example:
take a battery and hook a lite bulb to it... it turns on and glows, add a low resistance wire to the battery too, watch the lite bulb go dim... low resistance voltage drop.
That isn't even close to the same thing being discussed. That is just the current taking the path of least resistance. All of the current will flow through the wire instead of the bulb.
Most confusing one is voltage drop under load. Found this post a while back; Voltage drop under load explained well.
It's all about the batteries
That was a Very Cool link Ryedan.
I am Constantly Surprised by how Much I have Learned about Batteries on the ECF.
if voltage drop is such a concern with the milli ohm loss at the switch,negative connect post, positive connect post, thru the body of the mod, the connect points of the legs of the coil, then make the coil .25 - .5 ohms less than what you are shooting for. That should very easily make up for all those loses.
Thank you sir. I've posted that link a few times. AFAIK, few people have actually read it and/or understood it, but I keep trying
I didn't realize how long I had my old MNKE batteries until I got new Sonys and noticed the huge difference in heat on the atty. Checked voltage drop and I was getting 0.35 with the Sonys and 1.25 with the MNKE. I realized after seeing that I had been using the MNKE for over a year and a half. They're in my battery recycle bin now.
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