B is for Battery

Posted 17th October 2014 by Dave Cross
A battery is a little store of energy. It’s a collection of individual cells that connect to produce a given voltage and energy capacity. Chemicals inside the cells break apart and re-join, forming new chemicals. This releases electrons that flow around the circuit. They carry electrical energy to the coil where it is converted into the heat energy.

Li-ion batteries are called ‘safer chemistry’, why did the mod explode?

There was either an electrical short in the mod/atomiser or the battery had been damaged; this caused thermal runaway and the battery to vent.

What is thermal runaway?

Heat causes reactions to speed up and some of these reactions release yet more heat – making more reactions to release even more heat.

What is venting?

Batteries are designed so that when things start going wrong gases will be thrown out of the positive end (the nipple) to prevent it exploding.

So a battery that vents has failed?

No, it has done its job – the person has failed to use it correctly.

So, I'll ask again, why did the mod explode?

The venting gases need to be released from the mod body; if they are trapped inside it is like blowing up a balloon until it pops. Also, around half the gases released are highly flammable.

What causes a battery to do this?

A short circuit, damage and/or poor build quality – a whole number of things can cause it.

The gentleman in Wigan ran a pair of batteries down to 2Volts previously; we call this over-discharging. When this happens metal elements are plated to parts inside the battery and create an internal short.

There are different qualities of batteries?

Yes. A rule of thumb is that you get exactly what you pay for with them – skimping is a false economy. Cheap batteries do not perform as well, for as long or as reliably as more expensive ones.

How do I know what I am buying?

If it is cheap it’s a fake. Other than that you need to research vendors and makes to ensure that your choice will do what you want it to safely. The POTV forum is a great resource you can use.

The take-away key points:

  1. Only purchase batteries and chargers directly from the manufacturer or from a manufacturer-recommended source. Buying counterfeit or poorly manufactured batteries increases the chance of having an issue.
  2. Do not let a loose battery come in contact with metal objects, such as coins, keys, or jewellery. Metal objects can cross the electrical connections and cause an incident if the internal protection circuitry isn't functioning correctly.
  3. Do not crush, puncture or put a high degree of pressure on the battery, as this can cause an internal short-circuit, resulting in overheating.
  4. Do not place the mod or batteries in areas that may get very hot, such as on or near a cooking surface, cooking appliance, iron, radiator or the dashboard of your car in the summer.
  5. If you drop your mod on a hard surface, it can potentially cause damage the battery.
  6. If your mod gets wet, even if the device dries and operates normally, the battery contacts or circuitry could slowly corrode and pose a safety hazard.
  7. If you see any bulging, leakage or other abnormality from your battery, stop using it immediately.
  8. You get what you pay for.
  9. See point 8.
  10. And point 1.

 

Genuine AW sellers

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Further reading and support

 

Top Photo credit: lucybrett via photopin cc


 Dave Cross
Article by Dave Cross
Freelance writer, physicist, karateka, dog walker