Initial opinion was that the horrific fire in the Williams garage after the Formula 1 Spanish Grand Prix on 13 May 2012 originated in the KERS inside one of the race cars, as did a second (thankfully more minor) fire the following July.
Kinetic Energy Recovery Systems (KERS) store the energy of vehicle movement to boost engine power later, often using electric charge as the storage medium. This is another salutary reminder that devices designed to store energy can sometimes release it in unintended ways, as heat causing fire.
Our Macs and iOS devices may be a far cry from the complexity of a Formula 1 car, but they too have devices designed to store energy: capacitors and batteries.
Capacitors or ‘caps’ have a chequered history.
Acting as temporary stores of electric charge, they are used extensively in most computer hardware and other applications, such as ‘starters’ or ‘ballast’ for fluorescent tube lighting. They consist of conductive materials sandwiched with substances of low conductivity, or electrolyte. When manufactured to high standards they should last for 15 years, but cheap components are prone to overheating, electrolyte leakage, and conflagration.
With manufacturing driven to minimise the cost of components, some who procure supplies of capacitors have saved a few pence using cheaper sources. Many have turned out to be duff, so-called ‘counterfeit capacitors’: in the last decade, a series of fires in mainly industrial and commercial premises have been blamed on catastrophic failure of strip light ballasts.
In 2012, and since, warnings have been renewed after further fires. Skimping a few pence on those components must have cost insurers millions of pounds in payouts for fire damage.
Computer motherboards and other components, including batches of iMac G5 and eMacs, have also suffered ‘capacitor plague’ when counterfeits have somehow entered the assembly plant. Since first reports in 1999, successive waves have cost major manufacturers hundreds of millions of dollars to rectify.
Single-use batteries seldom results in disasters unless seriously abused, but now that we are recycling more waste, sporadic fires have occurred in battery recycling points. These usually result from disposal of several, perhaps many, batteries that are far from fully discharged. They can short out, causing a sudden dramatic rise in temperature, and a good chance of combustion. Because they contain toxic mixes of different chemicals, the residue from a battery fire is a tricky and costly mess to clean up.
Rechargeable batteries, most notably modern high-capacity lithium cells, are more worrisome still. In ideal conditions, they should behave perfectly well, but if you have ever seen a movie of a mobile or portable device that has failed, you will appreciate the hazard.
Battery fires have now been implicated in several aircraft accidents, including the loss of a Boeing 747 cargo jet in 2010, with the death of both pilots. Clamour continues for air shipments of lithium batteries, as well as devices like iPads that contain them, to be banned, and the US Postal Service has this year (March 2015) introduced stringent and complex rules concerning the shipment of lithium batteries and devices containing them.
Common features of these incidents include a lack of understanding of the underlying physics, the incessant drive to cut costs, and inadequate quality management as a result. At the moment many of us want banks to face greater legislative and regulatory controls because of their recent appalling record of failures, but there are few campaigning for the same in electronics and electrical manufacturing.
Perhaps principled stands based on safety by the US Postal Service and others will make the components industries self-regulate, and put a halt to crap caps and blazing batteries. Somehow I fancy, given the sums of money at stake, the only effective answer is going to be further legal compulsion.
Updated from the original, which was first published in MacUser volume 28 issue 14, 2012. Although ‘capacitor plague’ largely died out in 2007, sporadic problems continue, and strip light ballasts and lithium batteries continue to catch fire.