3-Stage Variable eGo with LED screen & Super kits Exclusive to GV 3 Stage Variable EGO(2 batts),Cone,5 TC Clearomizers IN STOCK NOW!!

[pmos69]

You're right in all of that.
But there is a further additional factor in the equation: Li-Ion batteries have different degrees of efficiency when delivering it's stored energy depending on the discharge rate, and that affects it's perceived capacity (in mAh).

source: Battery Performance Characteristics - How to specify and test a battery

Since different suppliers can test their bats at different discharge rates (typically at very low discharge rates), the mAh ratings between different bats may not mean exactly the same thing.

 

[pmos69]

Note at post #220 that cut-off voltage of the red is as low as 2.52 v, close to the 2.5 mentioned in the Battery University extract above as a "sleep" condition. My voltmeter shows that a Riva cuts-off at about 3.05 volts (loaded with 2.5 ohms) and a Joye eGo at about 3.23 (also loaded at 2.5).

Actually, ITA made a further reading after the battery cut-off (after letting the battery rest a little bit, it fired again). -> not very relevant in terms of the device performance, since it was after a first cut-off, but it shows the device still firing after that with lower voltages.
His readings, still loaded with 3 Ohms were:
VL: 2.03-2.24V ; 2.43-2.55V ; 2.76-2.80V

 

[JW50]

You're right in all of that.
But there is a further additional factor in the equation: Li-Ion batteries have different degrees of efficiency when delivering it's stored energy depending on the discharge rate, and that affects it's perceived capacity (in mAh).

source: Battery Performance Characteristics - How to specify and test a battery

Since different suppliers can test their bats at different discharge rates (typically at very low discharge rates), the mAh ratings between different bats may not mean exactly the same thing.

Based on the chart it does appear that 650 for an eGo with cut-off at 3.2 is in vicinity of 650 mAh for discharge rate of up to 14C. Riva(cut-off 3.05) at 750 mAh seems in correct neighborhood for up to 9C. Probably max discharge rate for either is in neighborhood of less than 4C. Chart suggests that Joye has been quite conservative with its 650 number. That this new VV eGo reduces the cut-off below the Joye eGo may mean that no reduction of time of vaping (as compared to a Joye eGo) will be encountered.

 

[JW50]

Actually, ITA made a further reading after the battery cut-off (after letting the battery rest a little bit, it fired again). -> not very relevant in terms of the device performance, since it was after a first cut-off, but it shows the device still firing after that with lower voltages.
His readings, still loaded with 3 Ohms were:
VL: 2.03-2.24V ; 2.43-2.55V ; 2.76-2.80V

Does the 2.03-2.24V mean a max and a min at same testing time? What this may suggest is some new technology that Battery University is not up to date on. Battery University does indicate that the "sleep" mode is designed into batt circuit protection by batt manufacturer. Perhaps the maker of the battery for the VV eGo has found that "sleep" voltage can be made safely lower.

 

[pmos69]

Yup, at the same testing.
The readings keep going up and down regularly and continually, but that usually just indicates it's not pure DC but some sort of switched regulator. A DC multimeter has a lot of difficulty getting a fixed reading on those signals.
As I've said before, the battery may contain some sort of hybrid circuit:

Seems to have some sort of hibrid circuit.
- Boost at Blue setting - (I only say boost because the readings are a little higher than a normal 3.7V cell.)
- (probably) boost + pwm at purple setting
- pwm (or boost + pwm) at red setting.

The purple and red should definitely be using some sort of pwm, since the readings on a multimeter keep changing. An rms reading should be more accurate.
The blue setting readings are constant, like a flat DC.

The end result and user experience is that at the Blue setting the performance of this device is very, very nice.
The other settings should be useful the ocasional stuff with too low resistance to use comfortably at the blue setting.

A pwm circuit also explains lower than cut-off voltages at the red setting.

 

[zoiDman]

Isn't it about time that someone get out a Dremel and cut one of these open to see what is inside making it tick?

 

[pmos69]

Rather use the device for a while first :/

 

[JW50]

A pwm circuit also explains lower than cut-off voltages at the red setting.

Not certain on that. Joye eGo is PWM and it cuts off higher than Riva. My feeling is that PWM tries to maintain relatively fixed output at something above 3 - Joye at 3.2 or so. With no boost, regulation all downward. Cell output at 3.2, duty cycle at 100%, no where to go but cut-off. If "regulated" is say 2.5 - perhaps you are right. But early stage output above 2.5?

 

[r77r7r]

Do you like it,pmos69?

 

[JW50]

Yup, at the same testing.
The readings keep going up and down regularly and continually, but that usually just indicates it's not pure DC but some sort of switched regulator. A DC multimeter has a lot of difficulty getting a fixed reading on those signals.

If you change meter to AC - anything?

PS - GotVapes is out of stock on 3VV eGo.

 

[JW50]

Atty resistance: 3 Ohms

Vu - Voltage unloaded
VL - Voltage under load

Fully charged - 5 led bars:
Vu: red: 3.03-3.3V; purple: 3.70-3.8V ; blue: 4.2V
VL: red: 2.80-3.1V; purple: 3.46-3.6V ; blue: 3.9V

With 3 charge led bars (while working):
Vu - red: 2.82-3.11V; purple: 3.47-3.60V ; blue: 3.90V
VL - red: 2.65-2.92V; purple: 3.26-3.39V ; blue: 3.68V

Going to 2 charge led bars (while working) - end of charge:
Vu: red: 2.68-2.95V ; purple: 3.28-3.41V ; blue: 3.69V
VL: red: 2.52-2.76V ; purple: 3.10-3.21V ; blue: 3.49V

Let me zero in on blue and show comparison to what I got from a Riva testing (on my multimeter - a Fluke 11) back in April. Showing loaded(unloaded). My numbers on the DC mode of meter (and at load of 2.5 ohms):
------------------------------From Blue Above-----------My Riva Tests
Off charger--------------------- 3.9(4.2)-------------------3.81(4.2)
Mid Way or so------------------ 3.68(3.9)-----------------3.37(3.7)
Near cut-off---------------------3.49(3.69)----------------3.05(3.4)

Seems like what is happening is a Riva type output but just cutting off earlier. From my experience, Riva near end of charge - not very satisfying. "Mid Way" not timed or anything - just between off charger and before cut-off. Riva, I believe, is not regulated and not PWM.

 

[dannoman]

Actually still have the black kits, just OOS on the singles...

If you change meter to AC - anything?

PS - GotVapes is out of stock on 3VV eGo.

 

[harmonic]

hummm if i had one of those VOLT batts with the voltage display i would have to try and put the vm display in my vv ego. now that would be nifty

 

[pmos69]

Not certain on that. Joye eGo is PWM and it cuts off higher than Riva. My feeling is that PWM tries to maintain relatively fixed output at something above 3 - Joye at 3.2 or so. With no boost, regulation all downward. Cell output at 3.2, duty cycle at 100%, no where to go but cut-off. If "regulated" is say 2.5 - perhaps you are right. But early stage output above 2.5?

PWM is a step-down regulation yes (well, not really regulation, just step-down. The regulation part is an add-on).
Maximum theoretical voltage of a PWM circuit is equal to the input voltage. In practical applications, it's always lower.
PWM is basically just switching the circuit on and off very quickly, generating something like a square wave. The longer the on part of the wave is in relation to the off part, the higher the "equivalent" voltage is. It's output is not a DC, like the direct output of a battery. Voltage readings give an estimate of what the "equivalent" DC voltage would be.
I'm over simplifying some things, but that's the general idea.

The output of the VV at the blue setting still seems to me (a bit) above what a 3,7V 650mAh cell would give out throughout it's discharge cycle.
ITA did a comparison with a 14500 device and the results of the VV at the blue setting were also a bit higher.
Regardless of it having a booster or simply a really good LiPo cell, the results are very pleasing.

 

[JW50]

PWM is a step-down regulation yes (well, not really regulation, just step-down. The regulation part is an add-on).
Maximum theoretical voltage of a PWM circuit is equal to the input voltage. In practical applications, it's always lower.
PWM is basically just switching the circuit on and off very quickly, generating something like a square wave. The longer the on part of the wave is in relation to the off part, the higher the "equivalent" voltage is. It's output is not a DC, like the direct output of a battery. Voltage readings give an estimate of what the "equivalent" DC voltage would be.
I'm over simplifying some things, but that's the general idea.

The output of the VV at the blue setting still seems to me (a bit) above what a 3,7V 650mAh cell would give out throughout it's discharge cycle.
ITA did a comparison with a 14500 device and the results of the VV at the blue setting were also a bit higher.
Regardless of it having a booster or simply a really good LiPo cell, the results are very pleasing.

I don't think I disagree with anything there. I can't disagree with the "very pleasing" as I have not personally tried the 3VV eGo. However, I have noted something "very pleasing" for a Riva just off the charger. To me, a noticeable difference exists between a Riva just off charger and a Joye eGo and difference is "very pleasing" for Riva as compared to eGo. Not every individual will find that difference "pleasing" as I have found it. Some, I suspect, prefer the lower voltage and power output of the eGo. It seems that this 3VV eGo may be taking advantage of this early higher voltage batt output to allow an effectively higher duty cycle if in blue, a typical eGo duty cycle in mid-select, and lower duty cycle than eGo typically in low select. If this is case I would think that once cut-off has occurred in Blue there should be some more runtime available in low or mid select - provided cut-off switch can be reversed. If all selects are off after cut-off in Blue, a charge for 5 seconds or so might turn switch back on and allow continuation at lower settings.

 

[pmos69]

A very nice analysis and I agree 100%.
The "joint" cut-off thing might have something to do with how the circuit works - If you imagine it has some sort of booster (and I really don't know) always on, and then applies a PWM step-down with 3 different settings on top of that, it makes sense that it would do that. Cut-off would just depend on the point the bat would be too low to fire the booster.
Don't have an oscilloscope at hand to look at the output and check any of that, though.

Anyway, one thing open to improvement on the device circuit, whichever it is, is the regulation part.
There's probably no actual regulation being done, just the stepping-up/down, and it could improve the experience even more, although at the expense of battery life.

 

[isoplus]

The top coil clear cartos which comes with the kit, are those ce2-4 or ce2 delux? I was wondering If I can get drip tips instead of ce2-4 cartos (if those are ce2-4 cartos)... I'm loving my ce2-delux and dont think will ever go back to ce2-4s ever...

 

[badkolo]

these are form a different company and we cant do exchanges on the kits sorry.

 

[EDO]

I have a bunch of Low resistant egot type b attys....will this work with them....I mean will the LR attys pop if I go to a higher voltage with the VV battery? Also how much longer are they compared to the regular Ego batteries? Thanks.

 

[pmos69]

I have a bunch of Low resistant egot type b attys....will this work with them....I mean will the LR attys pop if I go to a higher voltage with the VV battery? Also how much longer are they compared to the regular Ego batteries? Thanks.

LR attys and cartos work fine.
No problems with 1.5 Ohm attys at 4.2V

Here's mine along between a 650mAh eGo and a GG Slim: