Re: Flyguy and fire-bombing.

Flyguy of course thinks that the batteries have to be on fire before anybody would dump them. That's a rather more relevant error, but not one that he's gong to recognise.

That isn't what I get out of it. He recognizes that they shouldn't be dumped if they *are* on fire. The airplane must remain flying until the fire goes out.

No, SNIPPERMAN, YOU think that - I don't think they are safe enough to even consider their use in cars, let alone aircraft.

Which won't be for LONG!

You don't have a clue about battery condition monitoring. That size of multi-cell battery needs a minimum of two temperature sensors - one at the core of the battery to monitor how hot the cells are getting and another on the surface to give an indicator of ambient temperature. You need to keep track of the current flowing into or out of the battery, and the voltage across the terminals, and a moderately power microcontroller to make sense of what's going on.

Four more temperature sensors (at least) spread around the central sensor could give you early warning of a local hotspot. The parts aren't expensive, and squeezing extra wires into a multi-cell battery array isnt going to cost much either.

Once you've got that, you can make them much more reliable and a whole lot safer. Even the kind of battery you might use to back up rooftop solar needs that kind of monitoring though this doesn't seem to be universally appreciated - at a job interview a few years ago I did find myself pointing this out. It seemed to go down well at the time, but I didn't get the job.

Flyguy misses the ironic point, as usual.