Boeing 787 battery woes

The use of lithium-ion batteries in the Boeing 787 is at the center of the problem. All 50 of the Boeing 787s were grounded last week until investigators in the United States and Japan find out why two lithium-ion batteries failed in recent weeks. In my judgment I have a responsibility to help the public understand what is at stake with Boeing’s 787 lithium-ion battery woes. I also have advice for how Boeing should attack the problem.

If Boeing insists on using lithium-ion batteries, they’ll need to fit the cell stack with an active cooling system, which will include temperature sensors that monitor the temperature of each of the cells. Otherwise, Boeing may opt for a different battery technology, one that has a far better record when it comes to fire. I’d suggest nickel metal-hydride (NiMH), which is the same battery in a Toyota Prius. The energy density of NiMH is about 2/3 that of lithium-ion, so to get comparable energy storage you’d need about 50% more battery. This would increase the weight of a battery from 63 lb to about 100 lb, a difference of about 40 lb, which is less than the luggage allowance of a single passenger. It seems to be a bad gamble to risk the safety of the airplane for such a tiny weight savings.