So the mods you're using cut off at 3.2V under load? That's not my experience. On the rare occasions I've run one of the batteries in my DNA40 down to cut-off, it's at 3.1-3.2V open circuit. That means it was substantially lower than that under load. And if you cut off at 3.2V under load, you're leaving a substantial portion of the battery's capacity untouched.
Don't forget about Watts Law
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What? Did I say that I am using a mod that cuts off at 3.2V under load?
I simply gave the formula to use to find amp draw at a wattage at Low Voltage Cut-off.
I made up an imaginary mod to use as an example.
If you want to bicker pick someone else.
A PMIC is just one of a family of chips, it stands for Power Management Integrated Circuit. Basically you can buy ones specifically designed to handle battery management, display screens, current management, a buck/boost controller/regulator is a PMIC. Basically they're all off the shelf, ready to go chips that you can slap into a product to handle different things.
What most of the big players do are use chips like (Evolv) an Atmel chip acting as the brains of the operation eliminating the need for a number of separate chips. That level of design is beyond me, that's a real power engineer's territory.
I have no way of knowing what mods incorporate what logic, I know the SX Mini has limited ability to recognize a weak battery and will give a check battery warning if the batter isn't up to the task but it will keep on working. The DNA40 monitors the battery much more extensively and will reduce output to within a batteries limitations i.e. if you put in a 10A battery it might limit the mod to firing at 30W or less depending on the condition of the battery and what its calculations say are safe.
As far as worrying about batteries on a regulated mod, its not something that I think about because its rare that I ever go over 30W. But guys like Boden and Baditude give the most solid advice you'll find around here on how far to push a battery.
I used to go CDR x 3 - 20% or more from the total for a comfortable amount of headroom. I go with 3 because if you look at the discharge curves on battery specs, you'll see when they're pushed, you almost never get much more than 3.5V except for the first 200mAh or so, then its between 3.5V and 3V under load for the vast majority of the useful charge until the steep drop off when it dies.
Though I'll freely admit to pushing new batteries to damned near the limits found on the spec sheets on occasion.
Now for the does the mod "see" the coil and is it all one circuit. Yes to both. I don't know if you watched the buck and boost videos I linked, but they both show the bare bones basics of how the circuit works. I can't come remotely close to how well they're explained, Afrotechmods does a stellar job.
That's classic buck/boost and I don't think it can be any clearer that it is indeed one circuit from battery to load in either setting. Also you can ohm out the +/- on the battery sled to the +/- on the 510 and you'll get continuity with both, with an ohm reading on the positive because its reading across a few components.
I won't go into the theory too much, like where the extra amps go when the voltage is bucked. Needless to say it definitely "sees" the coil, it can even show you the resistance of the coil on the screen
The chip has to constantly compensate and adjust the pulses to maintain voltage across the load and it has to know the resistance to know how many volts to apply to get x watts.Actually, come to think of it, P Busardo did a video of the DNA40 showing how he could change the resistance on his lazy box and the DNA40 would instantly compensate to maintain the wattage output....because its constantly monitoring the resistance at the 510.
A PMIC is just one of a family of chips, it stands for Power Management Integrated Circuit. Basically you can buy ones specifically designed to handle battery management, display screens, current management, a buck/boost controller/regulator is a PMIC. Basically they're all off the shelf, ready to go chips that you can slap into a product to handle different things.
What most of the big players do are use chips like (Evolv) an Atmel chip acting as the brains of the operation eliminating the need for a number of separate chips. That level of design is beyond me, that's a real power engineer's territory.
I have no way of knowing what mods incorporate what logic, I know the SX Mini has limited ability to recognize a weak battery and will give a check battery warning if the batter isn't up to the task but it will keep on working. The DNA40 monitors the battery much more extensively and will reduce output to within a batteries limitations i.e. if you put in a 10A battery it might limit the mod to firing at 30W or less depending on the condition of the battery and what its calculations say are safe.
As far as worrying about batteries on a regulated mod, its not something that I think about because its rare that I ever go over 30W. But guys like Boden and Baditude give the most solid advice you'll find around here on how far to push a battery.
I used to go CDR x 3 - 20% or more from the total for a comfortable amount of headroom. I go with 3 because if you look at the discharge curves on battery specs, you'll see when they're pushed, you almost never get much more than 3.5V except for the first 200mAh or so, then its between 3.5V and 3V under load for the vast majority of the useful charge until the steep drop off when it dies.
Though I'll freely admit to pushing new batteries to damned near the limits found on the spec sheets on occasion.
Now for the does the mod "see" the coil and is it all one circuit. Yes to both. I don't know if you watched the buck and boost videos I linked, but they both show the bare bones basics of how the circuit works. I can't come remotely close to how well they're explained, Afrotechmods does a stellar job.
That's classic buck/boost and I don't think it can be any clearer that it is indeed one circuit from battery to load in either setting. Also you can ohm out the +/- on the battery sled to the +/- on the 510 and you'll get continuity with both, with an ohm reading on the positive because its reading across a few components.
I won't go into the theory too much, like where the extra amps go when the voltage is bucked. Needless to say it definitely "sees" the coil, it can even show you the resistance of the coil on the screen
Actually, come to think of it, P Busardo did a video of the DNA40 showing how he could change the resistance on his lazy box and the DNA40 would instantly compensate to maintain the wattage output....because its constantly monitoring the resistance at the 510.
The "coil" on top of a 510 is merely a heating element that has no bearing on the duty cycle of a battery due to the PWM's timer, what you are insinuating is that the battery "see's" the PCB in "mech mode" / mosfet full time, which would be highly inaccurate, would the battery also know when the wick is dry ? the PCB's are what measures the resistance of the coil, for whatever metal type / TCR value and also manage the battery. Cloudmaker's Ares's board, Evolv, Yihi, Dicodes all use a dedicated ground from the board to body NOT the 510 and have soldered fuse's built in ...................
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The battery see's the PCB board and coil as one circuit in the form of total impedance.
Set a a certain wattage the PCB varies the voltage to maintain the wattage across
different resistances resulting in no real world change in impedance the battery see's.
Change the wattage setting changes the impedance the battery see's.
The resistance of the coil has a direct bearing on the duty cycle of the PWM.
You can have a voltage with a set pulse duration and by increasing the voltage of the
pulses or, you can have a set voltage pulse and increase the durations of the pulse.
It's whatever these pulses average out too that determines power to the coil. this
is all done by the PCB circuitry using a voodoo curse discovered by an engineer
while on vacation in Haiti.
Mike
I think you maybe a little confused as to exactly how "digatal IC's" work through diode's.The battery see's the PCB board and coil as one circuit in the form of total impedance.
Set a a certain wattage the PCB varies the voltage to maintain the wattage across
different resistances resulting in no real world change in impedance the battery see's.
Change the wattage setting changes the impedance the battery see's.
The resistance of the coil has a direct bearing on the duty cycle of the PWM.
You can have a voltage with a set pulse duration and by increasing the voltage of the
pulses or, you can have a set voltage pulse and increase the durations of the pulse.
It's whatever these pulses average out too that determines power to the coil. this
is all done by the PCB circuitry using a voodoo curse discovered by an engineer
while on vacation in Haiti.
Mike
But what "some" don't also seem to understand is that a certain coil or any coil for that matter, doesn't represent the danger or (venting), simply put, a higher power (low ohm big I.D) coil needs more power, and figuring the total amp limit uses watts div by volts + 10 % apv efficiency, nowhere in the equation does coil resistance come into factor.
@sparkky1 Doesn't the resistance of the coil determine the pulse width
at any single set wattage?
Mike
at any single set wattage?
Mike
Coil resistance makes no difference at all in regard to amp draw on a regulated mod. This is the point I think OP was trying to get across.
All you need to know on a regulated mod is the following simple equation:
I = P / V
(Amps = Power / Voltage)
You take your set power and divide it by your battery input voltage (not output voltage at the coil). So, let's say we vape at 75W with a single battery. Therefore:
75 / 3.7v = 20A
Let's say we have a 2 battery series mod:
75 / 7.4v = 10A
And on the DNA-200 or another 3 cell series mod:
75 / 11.1v = 7A
As the battery gets below 3.7v, the amperage drawn will be higher. You must also factor in the inefficiency of the DC-DC converter (bucking or boosting). Bucking is more efficient and the inefficiency is negligible. Depending on the quality of the board, the total efficiency can be 98% or higher (Evolv uses high quality circuits on their boards).
Boosting is more inefficient. I am not an EE, but my understanding is it will be around 90% efficient at best. In theory a parallel battery mod will have the exact same battery life as a series mod. In PRACTICE, the parallel mod will drain faster because it must boost and boosting is more inefficient.
The bottom line, though, is I = P/V will give you a very good idea of the current drawn from your battery.
Yeah, I got that, a few posts later. I hope that the intended recipients of this information are able to wade through the rest of the fluff to get at the meat of the matter.
I had a conversation yesterday in another thread with someone who vented a battery in a three battery mod, vaping at 150 watts, with 20 A batteries.
I believe it was the wismec rx200 and lg HG2 INR18650, the brown ones. He said he had been vaping for a few hours at 150 watts, and then one of the batteries vented.
Wismec recommends 25A batteries, and I believe those are 20A.
EverReady Bunny thread
Meanwhile, the closest I have seen to a Regulated Mod exploding......ECF Member, MVP if IRC. Dropped it and the mod strock the floor bursting into flames.
Probably popped the internal Lipo, but the Mod held up to the pressure.
I Believe he chucked it into a Sink/bathtub...............quickly
Meanwhile, the closest I have seen to a Regulated Mod exploding......ECF Member, MVP if IRC. Dropped it and the mod strock the floor bursting into flames.
Probably popped the internal Lipo, but the Mod held up to the pressure.
I Believe he chucked it into a Sink/bathtub...............quickly
Something is missing from that story. Like he used two freshly charged cells and one that was at 2.6V then proceeded to vape for a few hours which drained the dead cell to -.1V. That make cell go boom.
Nice .pdf. Do you have one explaining how it operates under changing loads?
Regards
Mike
I didn't ask for more details, definitely not my area of expertise. I didn't ask if the three cells were married set, as I assume people know to do that.
sorry, it was 175 watts.
Here's the quote, it was in the womper woom
ETA:
it seems like, if you went down to 3.2v cutoff, 175 watts would be at just over 20A per battery. right? A lot would depend on the cells themselves.
It would be 18.2A per cell, but I think the problem is that most people assume the batteries will share the load exactly. Aside from that problem, there is a basic tenet that you do not build a circuit to 100% of the specified ratings. That seems to get lost in these discussions.
18.2 with no accounting for board inefficiency, right? If you assume 10%, then it's just over 20.
I would not go for 100% performance, just like I don't drive my car at 140mph. In this case, he was using 20A batteries, and the manufacturer recommends 25A batteries. Are there reliable 25A batteries, or is a three cell mod pushing 175w just a bad idea in general?
Nah they're likely cutting off at 3.2v or thereabouts (see the mods specs) and measuring voltage even when the mods not fired.
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