On 787s, Battery Fondling and Technology

[dam718]

I remember talking with an EE buddy ten years or so ago about a stress test that basically EVERYTHING that is not human must pass to get on a plane.

For lack of a better explanation,
take "device",
place in paint shaker machine-like torture unit,
shake the F out of it.
With the "device" running "normally", it must continue to function, no leaks, no rattle, no interruption of function. I don't recall the duration of the test, but seem to remember that is was administered in a variety of simulated environments (high humidity, extreme heat or cold, mixed conditions of half unit hot/half cold, partially submerged, .)
Point is, despite the high level of engineering used to specifically design a device that meet the tech requirements, in the end, to guarantee a unit and deliver it ready for a layman to attach to the plane, They filled it with epoxy.
It was no longer serviceable, it had a predetermined useful life after which it would be replaced. The tech just had to remove the old unit and pop in a new one. No inspection of internals. Works? yes...DONE.

I

We have similar stress testing for everything that will be permanently installed on a U.S. Submarine.

We even go so far as to light said "device" on fire and monitor the toxicity of the fumes to ensure that the cumulative effects of the burning material, combined with other expected toxins would not exceed the capacity of our emergency blowers to evacuate the fumes from the submarine within a specific time frame.

We also do shake down tests, g-force shock tests, submersion tests... You name it... Not that a submarine is ever exposed regularly to high vibration, high g-force shock, flooding, etc... But what if... What if we were subjected to continuous depth charge attacks for hours? What if we experience an undersea collision? They take every conceivable catastrophic event into consideration.

It's so much that the "R&D" cost far exceeds the standard cost of a consumer grade device, so something that appears in every respect similar to what you would use in an office building that costs $200, could easily be 20-30x that amount for use on board a submarine because of the cost of testing EACH DEVICE prior to shipping. It's ridiculous to a point, but necessary for safety of ship and crew.

I get it... But I don't like it...

I'm sure these batteries were tested to a similar degree of ......edness... If we used a cell from it in our PV's, you would have a PV with a retail price of $1000 or more... LoL

 

[windozehater]

i was trying to wrap my head around the 787 battery issue and a bulb(all be it a dim one thats all i have anyway)went off in my head. for all of my life my family was involved with cars, owned few dealerships, repair & body shops, so many times i have seen cars with wire fires lead/acid batts exploding and such, you could almost always count on poor grounds somewhere in the system whether it be a small amount of paint on a lug raising the resistance and ruining ecm internals or one memorable one was a extra long engine ground strap was causing some arcing in the front wheel bearings making them fail prematurly. anyway after that run-on sentence the 787 is carbon fiber right, i bet dollars to darwins that they have to make long runs of wire to ground and complete the circuit instead of using plane itself, this is probably a simpleton view of it but it reminds me to clean my PV's connections and throw away anything questionable.


sent by a hardwired hulk of a file cabnet sized computer using tap my fat fingers on a clickety keyboard