From the desk of Miss Know-All: Holy smoke... now it's laptop batteries that are exploding!

(Published on 12 September 2006 in 'Women at Work' - W @ W - a supplement of the Daily Mirror, Colombo, Sri Lanka)

Ever heard of exploding laptops that suddenly burst into flames? Good lord. Laptops have now got a mind of their own. Handle yours with care for if you treat it with a little disdain, it will lose its cool – heat up – and just explode!

But this is no banter. Dell recently recalled 4.1 million laptops as they felt that the batteries of these could short-circuit. These Dell laptop batteries could overheat and catch fire or explode. This isn't the first time in the computer industry that laptops have been recalled. HP and Apple have recalled laptop batteries in the past. But the threat of the battery exploding or catching fire is something new.

This really got me worried dahlings. As I work late into the nights often leaving the laptop on for hours on end, it was important I understand the mechanism of how the battery worked and why there were chances of it catching fire. Batteries have two terminals - a negatively charged terminal and a positively charged terminal. Energy from electrochemical reactions causes negatively charged particles called electrons to collect at the battery's negatively charged pole. When a battery is connected to a circuit, the electrons flow from the negative pole to the battery's positively charged pole. In this way a flow of charge or electricity is generated. The cells of a lithium-ion battery also contain separators that keep the positive and negative poles called anodes and cathodes apart.

Depending on the type of battery, electrons are generated in different ways. In a lithium-ion battery, pressurized containers house a coil of metal and a flammable, lithium-based liquid. Tiny metal pieces float in the liquid. Manufacturers try their best to limit the size and number of these metal fragments. If the battery gets hot through excessive use or recharging, the pieces of metal begin to move around. If a piece of metal gets too close to the separator that separates the anode from the cathode, it can puncture the separator and cause a short circuit. In case of a short circuit, the spark created could ignite the flammable liquid causing a fire. On the other hand if the short circuit causes the temperature inside the battery to rise rapidly, the battery could explode due to the increased pressure. Conversely if the short circuit causes the temperature to rise slowly, the battery can melt, and the liquid inside can leak out.

As users, we want small, light laptops that we can use for long time periods. We also want our laptops to have lots of processing power. Laptop batteries have to be relatively small, but have the capacity to hold a lot of energy and last a long time. Making lithium-ion batteries that can hold more power for a longer period requires its components, specially the separators, to be small and thin. The reduction in size makes it more probable that the batteries will short circuit or leak.

The thought of your laptop bursting into flames is a scary one. I have started treating mine with a lot more respect honeys. Before I go to bed I cover it with a lace cloth and caress it goodnight… the truth is that I want to be sure it’s not too hot on touch. I’ve come to the firm conclusion that a laptop is a woman. For no one but its creator understands its complexity. Even the smallest errors are stored in long term memory for possible retrieval. And finally – only a woman could explode on losing her cool!

Miss Know-All
wow@dailymirror.wnl.lk