Quote:
All EVA batteries will be converted to Lithium technology by 2016 and the existing BCM is not capable of charging them, has numerous fault issues and will be expiring in 2016.
Much of my knowledge about spacesuits comes from fictional asteriod mining and much of my knowledge about battery charging comes from a Dallas Semiconductor data-book. Regardless, this looks like a boondoggle to me unless lithium batteries are vastly different lead acid or nickel cadmium. Dallas fast charging chips may be pre-programmed for different battery compositions and one variant allows user programming over one of the incompatible Dallas 1/2/3 wire schemes. This pre-dated lithium charging but any device could charge any battery. The only difference is that charging speed and efficiency would be sub-optimal.
With lithium chargers, they typically seem to stop short of a full charge on alternate cycles. I presume this is to reduce a lithium memory effect. With nickel cadmium, the memory effect occurred around the 40% level. This could create a succession of false bottoms until a battery was unless. With lithium, I presume a memory effect occurs near the top. That would prevent a good old, lead acid style, linear regulator hooked to the mains, over-night trickle charge. Regardless, 6502 charging in potential fatal environment would be heavily logged and analyzed.
I am surprised that NASA would not make modification to a system which is mostly tested. From
They Write The Right Stuff, a highly productive NASA programmer writes four lines of software per year and when they find an error, they attempt to eliminate the whole class of errors. Furthermore, this is NASA which first isolated a (lead free) tin whisker on a Toyota accelerator pedal. If necessary, they'd slice and dissect a questionable battery.
Is it correct that, in 2016, NASA, who were mad about 6502/Am9511 FPU systems, dumped a reliable, stateful, 6502 battery charging system because it didn't stop short on alternate charge cycles? After exploding lithium batteries in laptops, exploding lithium batteries in phones, an
almost fatal incident in a Boeing 787, exploding lithium batteries in scooters, exploding lithium batteries in cars (not including the Tesla which caught fire three times), NASA said "Yeah, we want some of that. We haven't had any exploding astronauts, lately."