I’ve cooked about a dozen atties in the last two weeks

[Brewzz]

Most were atties that I’d been using since I started vaping in March, including rotating them for several days at a time on my VV mod since June, so I just assumed that they had just finally given up the ghost.
I also tried some HV atties that were gifted to me by a very generous ECF member (she wouldn’t even let me pay the postage). They all pretty much quit after less than 48 hours each, running at 5.6 – 5.8V. I had no idea how old they were, so I just let it go.
Now I’ve cooked two brand new 2.8 Boge atties, running at 4.5-4.6V, in as many days, and a barely used LR atty at 3.6V just popped on me less than 12 hours after I put it on.
My VV mod has worked flawlessly since I got it in late June; it’s just been this last couple of weeks that I’ve been having this problem. I have no idea what might be causing it. it still hits beautifully, right up until the atty fries.
I’m running two sets of AW IMR, and one set of protected 18350 batteries in rotation. They are all testing at 4.2 when they come off the charger, and are being changed and recharged before they get below 2.5. I usually vape a 40/60 PG/VG mix, but had the same thing happen with 80/20 PG/VG mix.
Prior to this last two weeks, I would check the resistance of my atty, adjust the voltage to get to 7.5 – 8 watts, vape on the atty until I started to notice a drop off in flavor or vapor (usually 3 – 4 days, and sometimes as much as a week), clean it with an overnight vodka soak, and put it back in rotation. Some of my atties had lasted for nearly six months using this method, about two months of that was using them on this mod.
The VV mod circuitry is pretty basic; a switch, a regulator chip, and a built in voltage meter. I’ve checked the voltage at the connector with a meter, and it reads within .03 of the built in meter.
I’ve been told that if there was a problem with the mod circuitry, it would shut itself down, so I must be just having a bad run of luck with atties. If the atties were all from a single order, I’d be inclined to think that maybe I got ahold of a bad batch run, but these are (were) atties from multiple vendors and multiple manufacturers, so I have to believe that the mod is to blame.
What, if anything can I do or check to find out what’s killing my atties?

 

[brittanyNI]

I don't believe in luck -- I believe in causation. I use plain vanilla gear and so far have literally never had an atty burn out, though I have had some need serious cleaning.

If your gear has been working fine with atties and suddenly you are losing them, and you are using the same juice, likely something has changed in your technique?

 

[Brewzz]

I don't believe in luck -- I believe in causation. I use plain vanilla gear and so far have literally never had an atty burn out, though I have had some need serious cleaning.

If your gear has been working fine with atties and suddenly you are losing them, and you are using the same juice, likely something has changed in your technique?

I don't believe in luck either, when it comes to things of this nature. You'll notice in my post that the statment concerning bad luck with atties was what I was told by someone else. I knew that there had to be something causing it, hence the post asking for suggestions on where to start looking.

This may be a bit premature, but I think I may have stumbled upon the problem, and it appears to have something to do with one of the pairs of AW IMR batteries.

While I was thinking about what's been going on, I realized that the atties always seemed to pop when I was using my #2 pair. I've retired that pair to a dark corner of my desk drawer, and replaced it with a reserve pair of protected batteries. Been using the same atty for going on three days, and no sign of trouble yet.

Another sign that points to the specific set of batteries is that I'm noticing that the regulator chip and the atty are staying much cooler now, than when I used the suspected bad battery pair.

Fingers crossed that my atty problem has been solved....

 

[Brewzz]

Here's an update, for anyone that's interested....
I'm officially convinced that it was a battery issue. Since I retired the suspect pair, I haven't fried another atty. Now, since my mod uses stacked 18350 batteries, all I have to do is figure out how I go about identifying which of the two from that pair is the culprit.

 

[Switched]

Here's an update, for anyone that's interested....
I'm officially convinced that it was a battery issue. Since I retired the suspect pair, I haven't fried another atty. Now, since my mod uses stacked 18350 batteries, all I have to do is figure out how I go about identifying which of the two from that pair is the culprit.

You don't figure out the culprit, you toss the pair. I know this a rather expensive solution (toss the pair) but think how much money you spent because of the bad pair.

When stacking batteries and the pair acts up, you always toss the pair. That is the cost of running batteries in series. That is the known recommendation. In retrospect if the pair was causing atties to pop, you are lucky you didn't fry your reg.

 

[DaveP]

If the mod were spiking the attys, it would do that with both sets. If the batteries are checking at 4.2 off the charger, that's good. You know that hot attys are either dry or receiving higher voltage. In your case, I would think voltage. The only other thing is one set is unable to sustain high currents and the other is hot in amperage capacity.

4.6 volts across a 2.8 ohm atty = 12.88 watts. That's a lot of heat, not out of range. A Riva 3.7v battery produces over 10 watts at that load.

P=EI, and the resistance of an atty is constant, so voltage under load has to be higher with one set of batteries over the other. Find a 15 watt 3 ohm wire wound resistor and check voltage using that as a dummy load. You will see the difference in voltage across a known resistance once you do that. Pulse it for just enough time to read the voltage.

Careful, it will get warm, but it will stand the load since it is rated at 15 watts power dissipation. It's a way to weed out the bad battery and replace just one. Or, you could chunk both and buy another pair, but you would always wonder ...

A car audio store will probably have them, but here's a link.
15 watt 3 ohm wire wound resistors

EDIT: This couldn't be a case of the inner contact on the attys being pressed into the atty when the atty is screwed on the mod, could it? That usually results in a shutdown due to overcurrent or frying the regulator. The inner atty contact should protrude slightly so that the outer ring doesn't contact the center contact. Have you checked the bad attys for resistance and found them open? If the center contact is the issue, you will read 2.8 ohms or whatever it's supposed to read.