Welcome to Part II.
Machaca:
It is my understanding both transcripts and videos of all the sessions will be available next week on the NTSB website.
But that will be without the totally hilarious captioning/transcription errors you got from the "live" feed.
Line 375:
YOU WILL NOTICE IN MY PRESENTATION, WHEN YOU SEE IT ON THE DOCKET, THAT I HAVE INFORMATION FOR BOTH LIVE IN MY AUNT AND METAL BATTERIES. -- FOR BOTH LITHIUM AND METAL BATTERIES.
Actually "For both Lithium-ion and metal batteries."
There is also some good stuff, like this, which pretty well lays to rest all of the speculation about the effect of electrolyte combustion and the contribution of the oxygen liberated within the battery electrode (which is small enough to combust only a very small fraction of the electrolyte):
WHICH THEN GOES BACK TO DR. CHIANG'S POINT. IF YOU ENGINEER A SYSTEM THAT HAS NO OTHER AVAILABLE OXYGEN, YOU TAKE AWAY THAT HEAT SOURCE, THAT ENERGY SOURCE, WHICH IS ROUGHLY, IN A GIVEN CELL, THE COMBUSTION ENERGY OF THE ELECTROLYTE IS 1 TO 2 TIMES THE ENERGY THAT IS CONTAINABLE IN THE CELL. IT IS NOT A SMALL AMOUNT. THOSE ARE MY TWO COMMENTS.
So the firebox
will reduce the worst case catastrophic energy release by a factor of two or three, in addition to containing it.
Also, a very nice sequence on the choice of Li chemistry:
(
ITALIC text is my insertion.)
Starting at 319:
>> UNDERSTANDING THAT EVERYTHING THAT WE DO HAS SOME RISK IN IT, ARE THERE CERTAIN LITHIUM-ION CHEMISTRIES THAT HAVE BEEN DETERMINED TO BE UNSUITABLE FOR CERTAIN APPLICATIONS AS FAR AS RISK LEVEL?
>> I DON'T THINK THAT QUESTION LEADS TO A PRODUCTIVE RESULT. TO BAN A CERTAIN TYPE OF THEM ASTRAY. -- TYPE OF CHEMISTRY.
>> NOT NECESSARILY BANNING. CHOICES PEOPLE HAVE MADE FOR A CERTAIN ENVIRONMENT. FOR EXAMPLE, ON A SUBMARINE, ON AN AIRCRAFT CARRIER, OUT ON A SATELLITE, ARE THERE CERTAIN CHEMISTRIES THAT HAVE BEEN RULED OUT THE CAUSE OF THEIR RISK?
>> WHEN WE WERE TESTING MODULES, WE WOULD IT MODULES WITH A " SAFER CHEMISTRY" AND ONES WITH A MORE DANGEROUS CHEMISTRY IN THE CELLS. THE PERFORMANCE OF THE MODULES DIDN'T FOLLOW. THE CELLS THAT WERE DEEMED SAFER AT THE MODULE LEVEL PERFORMED WORSE. SO I WOULD ADVISE A COMPREHENSIVE AND THOUGHTFUL TESTING PROGRAM AND NOT WORRY ABOUT WHAT THE CHEMISTRY OF THE CELL IS.
>> I WOULD COMPLETELY AGREE. I THINK THE IMPORTANT REASON TO SAY THAT IS I CAN BUILD A COBALT, A HIGH CHARGED COBALT CELL INTO A MODEL THAT MAY NOT FAIL AND COULD WEIGH A TON. SO I CAN MAKE THAT BATTERY IN PHOSPHATE AND IT MIGHT WEIGH FIVE POUNDS. SO THE SAFETY REQUIREMENT OF THE APPLICATION, WE WILL HAVE TO GIVE YOU THE LIGHTEST, MOST COST-EFFECTIVE SOLUTION. BUT YOU, THE USER, CAN SAY I WILL NOT TOLERATE THIS. I CANNOT ACCEPT THAT. THIS IS A FAILURE. THE NAVY PROGRAM HAS DEVELOPED A VERY CLEAR YOU CANNOT PUT THIS ON OUR SUBMARINE IF IT DOES THESE THINGS. THAT WILL DRIVE US TO CHOOSE THE SYSTEM DESIGN, INCLUDING CHEMISTRY AND EVERYTHING, TO DELIVER WHAT THEY WANT. BUT TO DECIDE THAT A CHEMISTRY CANNOT WE USED IS LIKE TRYING TO SOLVE A PROBLEM WITH THE FIRST GRAIN OF SAND.
>> WITH RESPECT TO APPLICATIONS, THE CHEMISTRY IS IMPORTANT IF YOU WANT A VERY HIGH RATE APPLICATION. WE WOULD CERTAINLY GO WITH LIKE A SPINNER (spinel?) OR A PHOSPHATE TYPE OF CHEMISTRY. IF YOU ARE NOT LOOKING FOR HYBRID (higher?) PERFORMANCE, THEN WE WOULD GO WITH [INDISCERNIBLE] SO I THINK WE WOULD GO WITH THAT MORE THAN THE SAFETY OF THE CHEMISTRY.
>> LIKE WISE. I THINK THE SAME WESTERN (question) -- ARE THERE SITUATIONS WHERE BATTERIES HAVE BEEN REPLACED BECAUSE OF THE FAILURE RISK BEING TOO GREAT? HE YOU HAVE AN ANSWER TO THAT?
>> NOT WITH RESPECT TO LITHIUM- ION. BUT WE HAVE REPLACED CHEMISTRIES LIKE LITHIUM PCX. WE DID NOT HAVE A GOOD REFLECTION OF WHAT THE ACTUAL ENVIRONMENT WOULD BE. FOR INSTANCE, IN THE ARBITER (orbiter), WE WANTED TO PUT IMPACT SENSORS ON THE WING SO WE COULD UNDERSTAND WHAT WAS GOING ON. AND IF AN IMPACT OCCURRED. SINCE WE DID NOT UNDERSTAND THE ALIGNMENT OF THE TEMPERATURES, WE ACTUALLY REFUSED TO ALLOW THEM TO USE THE BCX CELL BECAUSE OF IT BEING EXPLOSIVE. SO, YES, BUT NOT WITH RESPECT TO LITHIUM-ION.