Never seen an instance of negative anything on a lithium cell.feeling feisty today I see
Negative 0.1V
Oh never mind
Not for lack of trying.
But until I've seen it, I can only speculate.
Have you seen one?
Tapatyped
Don't forget about Watts Law
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Not for lack of trying.
But until I've seen it, I can only speculate.
Have you seen one?
Tapatyped
Just looked in the manual online, low battery cut off is 2.9V at this point it should reduce the output.
Can't see the efficiency listed but even at 100% efficient it would be pulling nearly 26A. @ 90% efficient its closer to 29A
This is similar to the current draw for a 0.15R build on a mech.
I definitely would not be happy at 75W with a 20A battery. Not too comfy with a 30A either as I like some headroom.
Manual says >25A battery should be used.
All you can do is pass on the information.
In Defense of the Regulated Manufacturers:
They are attempting to meet Consumer Demand on a Market with NO supporting Battery Manufacturers.
The Better Regulated Manufacturers, and there are many practicing this, are incorporating a Pulsed power at higher wattage to reduce battery stress. I.E. salvage Battery usable life and increase safety.
This still Requires an Owner to not be blind to responsibility.
200w mod - 10% for efficiency - 10% for overhead = ..........
Me, I rarely push 50% on a Single or Dual Regulated - just my margin of safety.
They are attempting to meet Consumer Demand on a Market with NO supporting Battery Manufacturers.
The Better Regulated Manufacturers, and there are many practicing this, are incorporating a Pulsed power at higher wattage to reduce battery stress. I.E. salvage Battery usable life and increase safety.
This still Requires an Owner to not be blind to responsibility.
200w mod - 10% for efficiency - 10% for overhead = ..........
Me, I rarely push 50% on a Single or Dual Regulated - just my margin of safety.
A market demanding increasing power and decreasing size.
The last decade and some has seen unparalleled battery tech leaps and bounds. Shouldn't be too hard to mfr within safe margins. Of course some of those margins will be outside of your personal safe zone.
But better limits and safer tech (balance charging for example) are easily within reach.
Tapatyped
Maybe he isn't stupid. Maybe he actually Read the Fing Manual. Which provides absolutely no guidance on battery selection. Nor any guidance as to why it might explode in his face by simply turning up a dial to the specified maximum advertised value.
This industry has a lot of growing up to do. It is selling these devices as mainstream, harmless consumer devices. And at least this particular device (which I own and use but well short of 75W) has a manual I grade as an F in terms of providing critical safety info. And apparently they are not harmless mainstream consumer devices, according to the direction this thread is going. But nobody told that guy when he bought it.
Our civilization is well trained in the idea that consumer electronic products can be safely used at their maximum specified capacity without spending hours researching often conflicting advice on internet forums. These devices are anomalies in that way, and I don't think it's fair to lay all that on the consumer.
He came here asking.
He got (likely, very likely) sound advice.
He refused to accept it.
Per lessifer... whom I'd consider a pretty honest guy from what I can tell.
Can't say I disagree with your thoughts on the industry.
But... when it comes to a blatant display of stupidity, it is what it is.
So maybe the person isn't stupid. The actions most definitely, undeniably are...
We all have our moments.
Tapatyped
I really meant "he" generically, without regard to the specific advice he may have gotten or may have ignored.
Then you changed the subject to "he" to respond to it.
"He" did something stupid by not taking good advice.
I cannot call "him" out as a stupid person. I can call "him" out for doing something stupid.
Context... it all matters.
Tapatyped
The online manual I have does not mention any battery guidance. Nor the printed version that came with the device (which had a 60W firmware). I'm curious what version you have...
download - Joyetech
Recommends Sony VTC4 on pg 2
Weak battery warning and reduced power on pg 8
The information is there, but not really very prominent. In my view it would be easy for somebody to miss. Especially if they were not used to dealing with technical documentation. It should be in big red letters on pg 1 of the manual so folks can't miss it.
With all due respect to Lessifer, from the perspective of a brand new member he is simply some currently unknown and anonymous guy on the internet contradicting the product manual by claiming dangers that are not in any way specified in the manual. You think it is good advice because you are of like mind and are well versed in the subject. The member in question does not have that benefit and has no reason to consider Lessifer's contradictory advice particularly good or bad.
My definition of "stupid" crosses a certain line that I don't quite see crossed here. YMMV and apparently does.
Hey, I didn't call him stupid. I was trying to help him not get dry hits and he refused to accept that he may need to back off from the max 75w that his mod will output. It was only after that that I inquired about what battery he was using, and attempted to inform him that running a 20A battery at 75w may not be a good idea.
Just to be clear, at this point, he had no idea what I was talking about, didn't actually know what battery he was using, or its amp rating.
Ignorance is not stupidity. My concern is that people have begun to take the shortcut of "use a regulated mod" instead of actually informing people of the concerns inherent to the batteries we use. There is less to be aware of when using a regulated mod, but there are still concerns that every vaper should be aware of.
The discussion about stupid wasn't between you and me
. I get what you are saying and that is why I entered the discussion criticizing the product manual. I'm in the same choir. I think education starts with that basic documentation. Very few buyers of that mod hang around here, nor should they be expected to do so, but they all get a manual so I think it's fair to pin much of this on the manufacturer.Since I have the same mod I played around with it a bit since this discussion started. I use mostly Samsung 25R blue wraps in my own Evic VTC Mini. I had a 25R battery in there showing half power on the mod's meter and tested at a resting voltage of 3.7V on an external meter. When I tried to fire it at 75W it would immediately drop to about 52W, more or less (it varied a bit on each fire but always under 60W I think).
I then replaced the battery with a freshly charged one and repeated. This time it started at 67W or so but after a few puffs it did fire sometimes at 75W, other times around 72W.
So it apparently has some programmed smarts, such that that worst case calculation of a full fire at or near 3.2V is probably very overly conservative. It doesn't seem to like to fire over 20A or so (assuming some board inefficiencies) unless things are very perfect. So there may be some idiot proofing in there. I'm not saying I like the idea of firing that thing on a regular basis at 75W but it *may* not be the death trap some might suggest after doing some worst case calculations. Neither of the batteries got more than just slightly warm to the touch, in a room with an ambient temp of about 63F. But I only vaped it for maybe 5 minutes, taking 2-3 puffs per minute and my puff times were probably only 5s.
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The discussion about stupid wasn't between you and me
Since I have the same mod I played around with it a bit since this discussion started. I use mostly Samsung 25R blue wraps in my own Evic VTC Mini. I had a 25R battery in there showing half power on the mod's meter and tested at a resting voltage of 3.7V on an external meter. When I tried to fire it at 75W it would immediately drop to about 52W, more or less (it varied a bit on each fire but always under 60W I think).
I then replaced the battery with a freshly charged one and repeated. This time it started at 67W or so but after a few puffs it did fire sometimes at 75W, other times around 72W.
So it apparently has some programmed smarts, such that that worst case calculation of a full fire at or near 3.2V is probably very overly conservative. It doesn't seem to like to fire over 20A or so (assuming some board inefficiencies) unless things are very perfect. So there may be some idiot proofing in there. I'm not saying I like the idea of firing that thing on a regular basis at 75W but it *may* not be the death trap some might suggest after doing some worst case calculations. Neither of the batteries got more than just slightly warm to the touch, in a room with an ambient temp of about 63F. But I only vaped it for maybe 5 minutes, taking 2-3 puffs per minute and my puff times were probably only 5s.
It would be interesting to get some of these mods on a decent stabilized power supply, and see what the actual current is at different input voltages. That way you would be able to see how effective the built in safe guards are. I would also be interested to see just how accurate the output is.
Well, they're also recommending a cell that is not labeled for individual sale, and that Sony has released a statement saying should not be used in personal vaporizers(A CYA move no doubt, but it's out there).Well I missed it and I was looking for it
The industry, if it exists in the future, has a lot of growing up to do.
I don't think any of the battery manufacturers are lining up to recommend use in e-cigs. The vast majority of these cells were not designed to be used in our application. Most are designed to be used within battery packs with well made, tried and tested protection circuits.
I don't blame them for not officially authorising use in e-cig's they are going to want to protect themselves against possible lawsuits.
I don't trust the manufacturer ratings on any battery, @ mooch has tested most of the batteries we use and given them his own CDR rating. Its interesting to note that of all the batteries tested so far there are very few that make the grade @ 30A.
https://www.e-cigarette-forum.com/forum/attachments/image-jpeg.529915/
The majority of the cells have been tested and made the grade @ 20A. In my opinion the mod makers should be limiting the output of the mods, and there for the required input so that they do not exceed current levels that the vast majority of cells can stand. Safety should come first. I accept that they can not cover off every battery type, there will always be some that put cheap rubbish into mods, but surly they should be providing mods that are safe to use for the majority of the cells available. At the end of the day these products are being marketed at the general public, not electrical/electronic engineers. To be clear, people should be able to use a mod at its maximum rated output without fear of explosion and without doing extensive research first.
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