Elon's comments have some validity, but there is a bit of grandstanding going on. Thermal runaway with lion batteries isn't a random event. It's very predictable and very preventable. 99% of lion batteries in use have a built in thermosensor so that they can charge correctly without exploding---because any lion battery will explode if charged too fast or if it goes into overvoltage.
So since all of the variables to prevent thermal runaway are know, it should make no difference how closely together they are placed. However in this case there is either a problem with the charging software---which isn't adequately performing and preventing the condition that is causing the batteries to overheat OR the batteries themselves (although in good working order) are not performing within the correct performance envelope that the software has been developed to use.
Screaming that placing the cells too close together is bogus. You laptop has cells placed equally close together as do all Tesla vehicles---and they can burn and explode just like the ones on the 787---yet that is a very rare occurrence. Because all of the charging parameters are known. Same applies to the Boeing batteries, but something is not performing according to plan.
In space, the parameters are completely different. Fire is the absolute worst case scenario in space and everything that can be done to mitigate the chance of one will be taken. Which is why the batteries on the SpaceX vehicles are spaced out they way they are. Yes, they know all of the parameters for the batteries, but the logistics of changing a battery in space are much different than those of an aircraft.
Boeing's fault in all of this is that something is not performing according to spec---and they knew that due to all of the battery swaps the Japanese airlines were doing. At that point they should have grounded and figured out the problem. But past Elon, others have already stepped up and criticized Boeings move to lions in the first place. Nickel cadmium batteries would have weighed 40 pounds more and have barely 1/1000th of a chance of thermal runaway that lithium ion batteries do. They don't charge as fast, but they are still well within the performance envelope needed by the 787.
So since all of the variables to prevent thermal runaway are know, it should make no difference how closely together they are placed. However in this case there is either a problem with the charging software---which isn't adequately performing and preventing the condition that is causing the batteries to overheat OR the batteries themselves (although in good working order) are not performing within the correct performance envelope that the software has been developed to use.
Screaming that placing the cells too close together is bogus. You laptop has cells placed equally close together as do all Tesla vehicles---and they can burn and explode just like the ones on the 787---yet that is a very rare occurrence. Because all of the charging parameters are known. Same applies to the Boeing batteries, but something is not performing according to plan.
In space, the parameters are completely different. Fire is the absolute worst case scenario in space and everything that can be done to mitigate the chance of one will be taken. Which is why the batteries on the SpaceX vehicles are spaced out they way they are. Yes, they know all of the parameters for the batteries, but the logistics of changing a battery in space are much different than those of an aircraft.
Boeing's fault in all of this is that something is not performing according to spec---and they knew that due to all of the battery swaps the Japanese airlines were doing. At that point they should have grounded and figured out the problem. But past Elon, others have already stepped up and criticized Boeings move to lions in the first place. Nickel cadmium batteries would have weighed 40 pounds more and have barely 1/1000th of a chance of thermal runaway that lithium ion batteries do. They don't charge as fast, but they are still well within the performance envelope needed by the 787.