1 + 1 = 3, 1 + 1 + 1 = Fire !

I have a habit of seeing patterns in things I read or see or hear and making connections that are so tenuous, you'd not believe them.

It can be handy, so I'll make logic leaps that get us the info we need. Or it'll let me figure out answers to problems. Trouble is, I can miss the obvious.

That's enough about me - what's the latest unconnected stories that I've spotted ?

The one that started me thinking was : USPS will not ship Li-ion batteries internationally any more. (Tomshardware link). The worry is that a certain type of rechargeable battery has more likelihood to catch fire or explode. I think the issue from the article is with batteries that aren't an integral part of the device. My Android phone would escape because you can't separate it from its battery.

Should you be worried ?

There's 3 main types of rechargeable battery :
NiCAD - the original rechargeable. Had a really limited life and low energy density (less hours with the torch lit).
Nickel Metal Hydride (NiMH) - the mk2. Higher energy density and lasts far longer.
Lithium Ion - best current tech. Far better energy density for the same life.

What's energy density ? My car uses a NiMH battery pack that lets it go a mile or so at 40mph without the engine on. There's a Prius coming that uses a Li-Ion battery that could go tens of miles at the same speed.

Ok - should you be worried ? Electronic Engineer says : No. (But don't sue me on that !) Every bit of consumer electronics that you use has gone through extensive testing to make sure it's safe. So the chances of that iPhone brewing up are slim to remote (unless the stories really have been suppressed).

And now for the Join The Dots - Chevy Volt buyers spooked by fires. (BBC link)

This one was a little scary when I read it originally. It wasn't a fire that started at the original crash (which is scary in itself), it was a fire that happened on a crash test car several weeks after the crash testing. That shouldn't happen.

If you're looking at the Volt or Vauxhall Ampera, I'd raise my eyebrows. But I wouldn't strike it off the "potential next car" list. Stuff like this can happen, it's best to predict it and anticipate it out of the design but when it does happen, manufacturers will sort it out quickly. Or their customers run away screaming which is really bad for business. That said, I avoided the Volt/Ampera because - it was taking too long to arrive, I distrust Vauxhall and the Lexus was shinier.

This weekend saw story number 3 : Fire in the Williams garage at Spanish Grand Prix. (BBC link)

Formula 1 cars these days are hybrids, where they have the engine assisted by an electric motor for up to 7 seconds a lap. What they think caused the fire was a spark from the KERS (hybrid motor thing) battery igniting fuel. Potentially very nasty. They got away with it in the pitlane fire, only one person was hospitalised.

Makes you think though - the car I'm driving around at the moment has a hybrid motor as powerful as the Formula 1 KERS motor (60kW). The batteries are bigger and are located behind and below the back seats, close to the petrol tank. In theory, there should be no risk as both fuel tank and battery are sealed.

But ... then you remember what we're driving now and what we used to drive - safety's not a problem. Hybrid doesn't add any risk that wasn't already there :
High voltage spark plugs - I've seen huge sparkage when we fired up a damp engine. It was like christmas lights going off.
Extremely flammable petrol
Batteries that can generate lot of hydrogen when charging. Hydrogen + Oxygen = KABOOM

Now I've scared everyone ... time for me to run to the bomb shelter.