Battery Voltages -- Surprise!

[JW50]

The eGo Booster is a bit puzzling. They show 4.7 volts on diagram above but look at this:

[/URL] Uploaded with ImageShack.us[/IMG]

In image above, 4.72 peak volts. Look at image at post number 653. Peak volts there (same eGo batt but without Booster) is 3.92. So - apparently - the Booster is boosting 3.92 v to 4.72 v - both peak volts with PWM. If the case, then average voltage should be the peak volts times the duty rate. Duty rate in this peak volt range about 82% based on Rocketman's tests of eGo w/3 ohm atty. Therefore, average volts of about 3.21 on eGo alone and about 3.87 for eGo with boost at high. The puzzlement comes from looking at average volts (i.e. cheapo meter) unloaded. eGo will read about 3.45 v. If PWM relationship holds, Booster at full should read about 4.1 v (i.e. 3.45 * 4.72/3.92). But, instead, eGo plus booster at full - unloaded, reads 4.7 v.

PS - In Rocketman's experiment with the eGo w/3 ohm atty, RMS volts were fairly constant through discharge; varying from ~3.5 to ~3.4 near end of cycle. Watts varied from ~4.2 to ~3.9. If experiment done with eGo booster, set at high, and if the 4.72 vs 3.92 relationship holds, the eGo with eGo booster would have RMS volts of ~4.26 to ~4.11 and watts would vary from ~6 to ~5.6.

 

[JW50]

An added comment about the eGo Booster. Seems possible it might take one to the 5.5 to 6 watt vape range - if that is ones like. (The boost diminishes at lower resistance ohms than the 5.5 to 6 watt example - exactly how much - unknown) But price of eGo Booster from Happy Vaper is about 67 or 68 bucks in US considering item and shipping. Also, I think, available through Totally Wicked at 65 plus shipping (called Tornado Booster) - probably in same 67 to 68 buck range with shipping there. But look back and see what DaveP got for 35 bucks. Dave can easily do 5.5 to 6 watts - and then some. Differences in shape and form between the two - for sure. But DaveP's device can still do the watts - and it can be varied even more - at - about - half the price. Don't think Dave's device is PWM other that the old fashion type - with a thumb. In my view, PWM does little for one except if the PWM is varied in a manner to make the watts at the atty more consistent through a discharge cycle. And even to get that consistence one likely gives up something in the way of losses in the circuitry that does the PWM. I have said this before in other threads - and I say again here - the eGo Booster is IMO pricey for what you get. My suspicion is that eventually we will see an eGo or an eGo knock off that will put the booster circuitry on an eGo (or knock off) circuit board to give either a higher voltage eGo or a varible voltage eGo with possibilities above the current Riva range. Just speculation about last comment.

 

[progg]

The eGo Booster is a bit puzzling. SNIP

An added comment about the eGo Booster. SNIP

Thank you for taking the time JW50.

 

[DaveP]

Dave,
sit down with a little paper and a pencil.
The NCP 630A, low dropout regulator, is a linear regulator, right?
a 14500 Li-ion cell is 900mah @ an average of 3.7 volts, the same as an eGo 900mah cell (3.33 watt hours)
Stacking 900 mah cells to give 7.4 volts gives 900mah @ 7.4 volts (6.66 watt hours).
If you run the mod @ 5 volts, about one third of the power will be lost as component heat.
If you run it lower, say 4.5 volts, about 40 % of the battery energy is lost.
If you run it about the same as a 3.7 volt e-cig with a 1.6 ohm carto, lets say a 3 ohm carto @ 5 volts, 1.66 amps, 8.3 watts, 4 watts will be lost.


The sealed or unsealed 510 connector will be sealed when the positive lead wire is soldered to the center pin.
The auto battery 510 had the hole left open to allow air to operate the switch. Most mods end up with the connector sealed by default.

FWIW, after using the Madvapes vv box mod for a couple of months, I've not noticed any appreciable heat from the electronic components using 1.6 ohm and 2 ohm Boge cartos, Smoketech 1.5 ohm dual coils, or my 3 ohm Little Dwarf dripper atty. The components are potted in clear silicone inside the box. That may insulate the components and contribute to keeping the case cool. The batteries stay cool, even with LR attys.

The 510 connector looks similar to an eGo connection. There's a solid center post supported by a silicone insulator ring inside the outer ring. There's no evidence of a hole. The solder lug must be connected by a screw, soldered in place, or machined as a loop on the bottom of the part. The bottom is a shadow through the silicone potting, so I can't see how it is made.

 

[KeysBum]

Bumping a classic

 

[r77r7r]

and again...................

 

[progg]

Perhaps at some point, one of this thread's contributors will dissect and analyze the eGo Twist. Other than the obvious, what is for me interesting but not understood circuitry, there seems to be something going on in regards to battery use time per charge. Using a 2.3Ω nom. (act. = 1.9Ω) joye 510 atty @ approx 4.2V, I'm getting about 1.8ml of fluid usage. This is with the 650mAh batt.! [Direct drip.]

What are they doing to get this batt to perform so well*?


*very early assessment -- 2wks

 

[br5495]

Perhaps at some point, one of this thread's contributors will dissect and analyze the eGo Twist. Other than the obvious, what is for me interesting but not understood circuitry, there seems to be something going on in regards to battery use time per charge. Using a 2.3Ω nom. (act. = 1.9Ω) joye 510 atty @ approx 4.2V, I'm getting about 1.8ml of fluid usage. This is with the 650mAh batt.! [Direct drip.]

What are they doing to get this batt to perform so well*?


*very early assessment -- 2wks

My wife and I have an eGo T Twist(1000 mHh) and they both work flawlessly. For this reason, I'll not dissect mine. However, I'd like to say that it is the best engineered variable voltage battery that I have tested, and I expect it will probably be more reliable than most other VV's out there. I say this simply because this is what I have become to expect from a genuine Joytech product.

I have tested this one at various voltages while under various loads and the voltages measure reasonably close to those indicated on the adjusting knob. The regulation is good with any resistance that I tried. However, I have not lowered the resistance to the point of shutdown to find out just how low it can go.

I'm glad to see the short protection with this one. With all the experimentation I have done in the past, I hate to think of the number of batteries that I have destroyed with a momentary short.

Although it has nothing to do with performance, I can't help but say something about the twist knob on the end of the battery. As far as I am concerned, this is the most practical way to adjust the voltage. It is much more convenient than multiple click circuits, and does not require a larger tube length like those with a knob on the side. I expect to see copies of this idea on other devices in the future.

So, I don't care how exotic the circuit is and have no need to analyze it. This thing just does exactly what it is supposed to do.

 

[Rocketman]

Isn't it a little depressing to get to the point you don't have to cut everything open just to see how it works

 

[JW50]

Isn't it a little depressing to get to the point you don't have to cut everything open just to see how it works

Maybe new or maybe something not noticed before - but, if not revealing too much PI, where in the world is SouthEasten? Is that a city maybe? Trying to stay on topic - are there any surprises in voltage in SouthEasten?

 

[Rocketman]

Southeastern Louisiana
Thanks, 3 years and I never noticed that.

and to stay on topic, we have electricity to charge PVs

 

[progg]

My suspicion is that eventually we will see an eGo or an eGo knock off that will put the booster circuitry on an eGo (or knock off) circuit board to give either a higher voltage eGo or a varible voltage eGo with possibilities above the current Riva range. Just speculation about last comment.

Hey, JW. I was hoping you'd arrive... You're not the lone prescient one ^^^^, but surely you've got .02 to add about the Twist.

 

[JW50]

Hey, JW. I was hoping you'd arrive... You're not the lone prescient one ^^^^, but surely you've got .02 to add about the Twist.

Actually, yesterday was the first I was aware that the Twist existed. Information at the link you provided is interesting. I noted that the 650 mah Twist was 98 mm in length as compared to the "standard" 650 at 75 mm. So 23 mm added length. An eGo Booster would add 38 mm or so in length. I note that the Twist is price listed at 29.99 at the link site whereas the "standard" is listed at 23.99. That $6 premium certainly compares, from consumer point of view, quite favorably with the $67 or so cost of the eGo Booster. On the surface anyway, one would think that the eGo Booster is a dead product.

The voltage curve provided in the info at the linked site is interesting. I wonder what kind of voltage is depicted on that chart. RMS voltage, average voltage, cheapo meter voltage??? Wonder what real watts provided? I note that a charge cycle life as reflected in that curve is basically 170 hits. At 9 seconds between each hit that is about 25 or 26 minutes. The 5 second pause time is likely too short for typical vapers but even at an 11 second pause time total cycle life would only go to 42 to 43 minutes. Of course, those minutes mentioned are minutes at the maximum voltage setting.

But do agree with br5495 that Joyetech products are usually top notch. I'm planning on trying one of those Twists. Meter readings matter little use if the thing "works well".

PS - On issue of eGo Booster being a dead product. Had previously seen the product offered at Happy Vaper and at Totally Wicked. In a check today of products available at those vendors I did not find the eGo Booster. Possibly I overlooked. But it seems that the product is indeed dead.

 

[JW50]

Gave some more thought on the voltage curve in manufacturers info and the 25 or 26 minute cycle life mentioned. That voltage curve is for the most part pretty linear. Lets call it 4.75 volts at start declining to 4.35 volts at, lets say, 180 hits. Info given says load is 2.2 ohms. Lets say average voltage is 4.55 volts (4.75+4.35 with sum divided by 2). So, on average, a current at "hit" of 2.07 amps. That current at 4 seconds is 2.3 mah (i.e. 2.07 amps, that times 4 seconds, that result divided by 3600 seconds per hour.) Then, approximately - close, 180 of those till avalanche of voltage at 180 hits. So, 2.3 mah times 180 hits is 414 mahs. That is only 63% of the 650 mahs "promised". Where is the math off? Or is it off? Maybe taking the batt to above its natural 4.2 at start causes this? Or an average of 4.55 above the "natural" average of 3.7 volts. But, thinking the curve is loaded voltage. The 4.2 at start and 3.7 average are typically unloaded, un-PWM type voltages. Very confused here. Looking for guidance. 25 minutes or 45 minutes usually is something to complain about. But either would handle the typical "smoker's break". Just better re-charge while back at work! Any insight appreciated.

An edit PS. The manufacturer's info and "curve" mentioned is at "Twist" link provided by progg.

 

[Rocketman]

I kept an evaluation unit (650mah eGo-Twist) for about a week before passing it on to another.

I have since ordered a couple 1000mah Twists, one for the wife and one to take apart (oh boy, oh boy )

At a voltage setting close to cell native voltage (3.6 to 3.7 volts) the charge life compared to a standard eGo.
Set at a higher voltage the charge life went down, duh.

The standard eGo uses a PWM switch to control native cell voltage via duty cycle to regulate output voltage. RMS values seem to be fairly level from full charge to cutoff even through you can't tell that from a "cheap meter"

The eGo booster outputs an elevated PWM signal from a standard eGo, but at a higher, boosted voltage.
Both with a pulse frequency of less than 100hz.

The Twist seems to use a 'real' boost controller, but I have not opened one to verify what is inside.
The Boost controller appears to not be running at minimum voltage setting of 3.2 volts. That would be in line with native cell voltage passing through a series control mosfet, inductor and the series drop of a schottky diode.
At higher settings the boost controller starts running, and error feedback (slower than converter frequency) controls the output voltage. The feedback loop time constant causes a small sawtooth component of the output as it turns the controller on and off as the output crosses above and below the set point. The average Vs RMS value of this mostly DC output (with a small sawtooth component) does not seem to produce the "cheap meter effect" you get when trying to measure the voltage of a PWM waveform like from the regular eGo.


Oh darn, correct some typos and lose the 'Likes'

 

[JW50]

I kept an evaluation unit (650mah eGo-Twist) for about a week before passing it on to another.

I have since ordered a couple 1000mah Twists, one for the wife and one to take apart (oh boy, oh boy )

At a voltage setting close to cell native voltage (3.6 to 3.7 volts) the charge life compared to a standard eGo.
Set at a higher voltage the charge life went down, duh.

The standard eGo uses a PWM switch to control native cell voltage via duty cycle to regulate output voltage. RMS values seem to be fairly level from full charge to cutoff even through you can't tell that from a "cheap meter"

The eGo booster outputs an elevated PWM signal from a standard eGo, but at a higher, boosted voltage.
Both with a pulse frequency of less than 100hz.

The Twist seems to use a 'real' boost controller, but I have not opened one to verify what is inside.
The Boost controller appears to not be running at minimum voltage setting of 3.2 volts. That would be in line with native cell voltage passing through a series control mosfet, inductor and the series drop of a schottky diode.
At higher settings the boost controller starts running, and error feedback (slower than converter frequency) controls the output voltage. The feedback loop time constant causes a small sawtooth component of the output as it turns the controller on and off as the output crosses above and below the set point. The average Vs RMS value of this mostly DC output (with a small sawtooth component) does not seem to produce the "cheap meter effect" you get when trying to measure the voltage of a PWM waveform like from the regular eGo.


Oh darn, correct some typos and lose the 'Likes'

Just thinking a bit about the PWM comment and its possible effect on RMS voltage. From the voltage curve provided in manufactures info, voltage ran from about 4.75 down to 4.35. This suggests watts on the 2.2 ohm atty used in the testing of about 10.3 watts at start of a discharge cycle to about 8.6 watts toward cut-off. This is the case if those volts are RMS volts. But with PWM kind of thinking those volts on the curve are not RMS volts and that actual watts being produced are lesser. Translating peak volts or average volts with a saw tooth wave form to RMS volts I think differs from the translating if a square wave form. The square wave form was the case, I think, for the un-boosted eGo. Of course, the meters and the math don't make much difference if device "works well". I'll have a couple soon to find out if it "works well" for me.

 

[progg]

Gave some more thought on the voltage curve in manufacturers info and the 25 or 26 minute cycle life mentioned. That voltage curve is for the most part pretty linear. Lets call it 4.75 volts at start declining to 4.35 volts at, lets say, 180 hits. Info given says load is 2.2 ohms. Lets say average voltage is 4.55 volts (4.75+4.35 with sum divided by 2). So, on average, a current at "hit" of 2.07 amps. That current at 4 seconds is 2.3 mah (i.e. 2.07 amps, that times 4 seconds, that result divided by 3600 seconds per hour.) Then, approximately - close, 180 of those till avalanche of voltage at 180 hits. So, 2.3 mah times 180 hits is 414 mahs. That is only 63% of the 650 mahs "promised". Where is the math off? Or is it off? Maybe taking the batt to above its natural 4.2 at start causes this? Or an average of 4.55 above the "natural" average of 3.7 volts. But, thinking the curve is loaded voltage. The 4.2 at start and 3.7 average are typically unloaded, un-PWM type voltages. Very confused here. Looking for guidance. 25 minutes or 45 minutes usually is something to complain about. But either would handle the typical "smoker's break". Just better re-charge while back at work! Any insight appreciated.

An edit PS. The manufacturer's info and "curve" mentioned is at "Twist" link provided by progg.

Be forewarned -- I'm a rookie at all this.

Near as I can figure your math is right. Are the 650 mAhs "promised"? Is the DoD restricted (cell protection) to X% in response to boosting the "natural" average of 3.7 volts?

 

[JW50]

Be forewarned -- I'm a rookie at all this.

Near as I can figure your math is right. Are the 650 mAhs "promised"? Is the DoD restricted (cell protection) to X% in response to boosting the "natural" average of 3.7 volts?

I call it "promised" as that is what manufacturer rated it/marketed it at. If it fell short of the "promised" I'm not inclined to sue. Lot's of BS out there - some worse than others. Joytech - my experience/belief - usually on conservative side of any any "BS". I tend to think that if voltage is "boosted" one is not likely to get those "promised" mahs. But if one likes to vape at a 4 second "puff" and only wait 5 seconds till another, just don't expect that you can do that all day on a single batt that is rated at 650 mah. Not sure I understand the other part. I know I should probably know what "DoD" is - but not clicking with me at this moment My belief is that "natural" voltage of lithium ion batt is that they produce an unloaded average voltage of 3.7 through a discharge cycle. Some chemistries of Li-ion differ - but most at about 3.7 average. Start at at about 4.2, then decline with use. Average from start to cut-off about 3.7. This without circuit manipulation and/or boosting. A regular eGo "manipulates". Doesn't give 4.2 at start but doesn't give "normal' bottom at cut off either. It's circuitry is seeking more "consistent" voltage throughout entire discharge cycle in comparison to no circuitry at all. If wrong here - hoping Rocketman or others will correct me. But, proof is in pudding. I've got a 650mah Joytech batt that I got 16 to 18 months ago that still "works well" and has helped to keep me away from the devils. I'm hoping that the Twist makes it more "cigarette like" and easier to obtain consistency, consistency being my biggest grip about ecigs. (I'm one of those "smokers" who know I must quit - but don't really want to. But I've quit but still looking for exact or better experience from "non-smoking".) But if not, still got my 16/18 month old doing well.

 

[progg]

JW , just to give you an idea of what to expect if my experience holds true -- 650 mAh, at 1.9 ohms, 510 atty use approx. 1.8 ml of liquid,direct drip. Minutes as a unit of measurement are difficult for me. Vaping habits vary to the circumstances. DoD = Depth of Discharge. I think the normal lion is 80%, am guessing the twist would be less considering the potential strain on the battery. Speculation on my part.. Don't know the C rating etc.. (a bunch of etc including my knowledge deficit ..)

I'm getting consistency from the twist till the avalanche. The gradual drop off is barely noticeable. I've been using a regulated VV device for about 1.5 years , so the experience isn't new to me. I think you'll be pleased. (I didn't want to quit either, I was driven there. VV has given me the most pleasure, vapewise. Swedish Snus gives me more than vaping.)

 

[JW50]

progg, on my scale, 1.5 years makes you a veteran. If understanding correctly, a 650 eGo twist takes you though 1.8 ml of liquid. Just approximating, I'm guessing that's about half a day. If two batts will take me through a day I think I'll be delighted with the twist. If the charging life of the batts last for 12 months plus, even more delighted. For you, in using the twist, do you vary the voltage setting through a discharge cycle? It might be the case that if discharge life is measured in terms of ml of liquid consumed that any voltage setting would give a similar result. That is, and this is total speculation, maybe higher voltage setting "consumes" more than a lower setting - shorter period for higher settings but "consuming" faster. I agree that Swedish Snus has a positive role in avoiding the devils. Very useful I think where longer periods of time occur where either smoking or vaping not appropriate. Also good when the batt dies and no second one at hand or when the juice runs out and no refill resource around because one forgot to bring it along. For me, the Snus gives me some comfort against those possible inconsistent ecig periods (or, trying to stay on theme, against those voltage surprises). General dry mini mint I find quite satisfying. Zero volts there - perhaps a surprise to some.