Use caution on VariStack/VV350

[scalewiz]

I kinda liked that little thing, the VariStack; inexpensive and actually worked quite well. But, anyone using these should take some caution. Mine quit working and began smoking the other day, so I very quickly undid the bottom and dumped the batteries, 2 AW IMR 18350s. No massive meltdown occurred, but my VariStack seemed done. Tonight I took it apart for an examination of the unit and the batteries. What I found was:

The wiring in these is VERY small. I estimate the wiring in these, even the wiring to the connector itself, to be no larger than a 30 gauge wire! Very much against the advice of any modder, since the currents needed in some cases cannot be carried by a wire this small.

The end result is that there is a very small wire that runs from the bottom of the battery housing, along the side of the stacked batteries, up to a small circuit board. This is the wire that carries the negative supply current. Since that small of a wire could not carry the current continuously, the insulation began melting, along with the insulation wrap around the batteries. This caused the batteries to short out through this wire, and the wire melted through, but not before melting through the battery wrap!

I understand these are inexpensive and make a nice device for trying out VV without breaking the bank. But, be careful. Using these at currents some of us try to attain can cause serious problems simply due to the size of the wiring.

 

[lokivapor]

I just ordered one how long did it last

 

[scalewiz]

Don't get me wrong; the thing wasn't all that bad, really. It worked really well for about a month and a half. Mine may have had a few problems, though. They say you couldn't use LR or dual coils on it, but even down below 2 ohms I never had any problem with it firing. Never once saw any type of error code get generated by something I did wrong. I'm reasonably sure that I didn't have a short to cause it to fail, since the device in question at the time worked great on all my other batteries/mods.

Probably the biggest complaint overall was batteries. Had to use button top; flat tops would not make contact inside on the positive end of the stack. AW IMR batteries all seemed to be flat top; had to put a small solder button on top of each battery positive terminal to make them work.

The voltage output was about .5 to .7 volts higher than what was shown on the display, but being variable, it really didn't matter. Just don't think that a 3 volt reading is really that low; more like an unregulated single battery device at 3.7 or so.

Would I buy another one?; probably not, even though I kinda liked it. For about the price of 2 of them, I would move up to one of the metal tube types. Only problem is that I now own several 18350 IMR batteries.

 

[Highwayman1224]

Don't get me wrong; the thing wasn't all that bad, really. It worked really well for about a month and a half. Mine may have had a few problems, though. They say you couldn't use LR or dual coils on it, but even down below 2 ohms I never had any problem with it firing. Never once saw any type of error code get generated by something I did wrong. I'm reasonably sure that I didn't have a short to cause it to fail, since the device in question at the time worked great on all my other batteries/mods.

Probably the biggest complaint overall was batteries. Had to use button top; flat tops would not make contact inside on the positive end of the stack. AW IMR batteries all seemed to be flat top; had to put a small solder button on top of each battery positive terminal to make them work.

The voltage output was about .5 to .7 volts higher than what was shown on the display, but being variable, it really didn't matter. Just don't think that a 3 volt reading is really that low; more like an unregulated single battery device at 3.7 or so.

Would I buy another one?; probably not, even though I kinda liked it. For about the price of 2 of them, I would move up to one of the metal tube types. Only problem is that I now own several 18350 IMR batteries.

Since you own several 18350's, you should get a new VV Reo Grand so you can happily vape your face off!! Just got one a couple of weeks ago & REALLY like it!

 

[Adam the Aussie]

I've got 3 varistacks, love the size and the simplicity. I've had one for about 4 months and it's still working fine, the other two I've had for about a month. They have their limitations, sticking with 3ohm cartos or the 2.8 ohm Vivi Nova stems seems to work best. I've had a couple of issues with them, the most concerning was yesterday when after putting in a new set of batteries and twisting on the end cap, the mod started firing by itself. I quickly removed the batts and then put them back in and everything has been working fine since. I guess we just need to be vigilant when using cheap mods like these, we're not dealing with a ProVari here, these are cheap for a reason.