When old ideas would be just fine

"System power on off switch"
by Dhanu under a CC license

My car had a flat battery the other day. Again.

It's that kind of problem that is simple to understand, quick to realise and easy to solve. But it's annoying. Very annoying. And it really makes you wonder: why cars - all cars - can't have battery indicators; the kind of battery indicators that actually indicate how much juice (and life) the battery still has.

Yes, I know, top end models have it. Newer models, from 2006 onwards, are increasingly featuring things like that. But why does it have to take soooooooo long to have things like that in a car? The charge level indicator is something that every consumer appliance with a rechargeable battery has been equipped with the last few decades. It's nothing too sophisticated. It's an old idea. And if one thinks of modern consumer electronics, such as mp3 players, laptops, etc., one can see that, nowadays, there are much more sophisticated - and precise - ways to predict remaining battery usage time. Judging from the prices of such devices, the electronics in question can't be too expensive.

So why does the car industry ignore that? I understand that a flat battery happens once every 3-4 years but it is still annoying and as a problem it seems extremely easy to prevent (two factors involved: low amount of energy stored in the battery and/or reduced capacity of the battery to store energy). True, the car industry would need to adapt the circuits in question to the specifications of the battery and the consumption patterns of their cars. To be fair, that does involve some work, since - unlike mp3 players - cars have a very wide spectrum of power needs. The immobilizer circuit, for instance, doesn't take too much power to run, but the ignition on the other hand, does. Also, it's the temperature span the battery operates under. Most mp3 players spent their working lifetime indoors or in a pocket heated by the body temperature; car batteries are not that lucky. And on top of that, the automotive industry typically needs to test everything for reliability, both individually and as a whole. But still, how hard can it be?