Boeing continues to stand by lithium-ion (li-ion) batteries despite Airbus's decision to remove them as a power source on the A350XWB family due to uncertainty about battery failures on two 787s in January.

Repeating a remark by Boeing chief executive Jim McNerney on 30 January, the company says that nothing in the ongoing investigations of the battery failures have revealed that would alter its decision about using li-ion as a back-up power supply and starter for the auxiliary power unit on the 787.

"Boeing is confident in the safety and reliability of lithium-ion batteries," Boeing says.

Indeed, the li-ion chemistry offer "significant benefits" when appropriate protections are in place, Boeing says.

All 51 787s delivered to airlines have been grounded since 16 January after two incidents of li-ion batteries overheating and in one case catching fire.

Several investigations, including separate probes by the Japan Transport Safety Board, National Transportation Safety Board, Boeing and the Federal Aviation Administration, have concluded that a short-circuit in one of each batteries' eight cells led to a chain reaction called thermal runway. But none of the probes have discovered the reason why the cell experienced the short-circuit, and why the protections designed into the battery to prevent a chain reaction did not work.

The inicidents have since shined a spotlight on the industry's quiet move to transition from nickel-cadmium (ni-cad) batteries to li-ion, which began with Boeing's decision to select the latter for the 787 in 2005.

Airbus also selected the same kind of battery to serve the same roles for the A350 family. Boeing chose a battery designed by Japanese firm GS Yuasa for the 787, and Airbus picked French company Saft to supply the battery.

Source: Air Transport Intelligence news