What does it mean to "stack" batteries?

[Carla Sebrina Spahos]

Hello!

Yesterday, when at my local B&M store I purchased the Tesla. The clerk who helped me in my purchase told me adamantly to definitely not stack my batteries. I assured her I wouldn't, but I really wasn't sure what she was talking about. I didn't stop to ask because I was so excited to get home and try out my new toy

Thanks in advance

 

[Baditude]

In a move to acheive higher voltage in an un-regulated (mechanical) mod, some vapors would "stack", or use two smaller batteries end-to-end. For example, use two 3 volt batteries to acheive 6 volts. Stacking batteries has always been looked down upon because the practice increases the risk of battery dysfuntion, hard-shorts, and disasterous battery catastrophy. This practice could put the vapor at serious risk of injury.

More recently, a few of the regulated electronic APVs were actually designed to use stacked batteries, but these devices had built-in protective circuitry to do this more safely.

 

[tj99959]

Unsafe practice from the early days of vaping. Back in the day it was the only way to get more than 3.7v (before VV). In the modern vaping world there are safe ways to boost the power, so why would a person even want to stack batteries anymore.

Basically stacking batteries is like putting two batteries in a flashlight, just with more powerful batteries.
The problem is that you have to get everything right every time, it only takes one mistake to have a disaster.

This is what *can* happen if you make that one little mistake.
Lithium Ion Battery Explosion - YouTube
What the video doesn't show is that what took 30 minutes to happen when charging can happen in a millisecond when discharging.

 

[Baditude]

Another example here: http://www.e-cigarette-forum.com/forum/new-members-information/190146-pictures-serious-battery-failure-imr-18650-a.html#post3265928

The above incident was not caused from stacking batteries, but doing so could result in the same disaster.