Airbus says it will not use lithium-ion batteries in its forthcoming A350 plane because of problems that have grounded rival Boeing's 787 Dreamliner.
The European planemaker said it would use traditional nickel-cadmium batteries instead, as already used in the A380 and other models.
Investigations are continuing after battery problems came to light on 787s operated by Japan's top two airlines.
Airbus said they remained "unexplained to the best of our knowledge".
The firm said it did not expect any further delays to the launch of the A350. The maiden flight is due to take place later this year, with the first passenger flight expected in the second half of 2014.
In a statement, Airbus said it was "confident" that the lithium-ion battery that it had been developing with French battery-maker Saft was "robust and safe".
It added that A350 test flights would continue with the lithium batteries.
"However, to date, the root causes of the two recent industry Li-ion main batteries incidents remain unexplained to the best of our knowledge," Airbus said.
"In this context, and with a view to ensuring the highest level of programme certainty, Airbus has decided to activate its Plan B and therefore to revert back to the proven and mastered nickel-cadmium main batteries for its A350 XWB programme at entry into service (EIS).
"Airbus considers this to be the most appropriate way forward in the interest of programme execution and A350 XWB reliability."
The A350 is intended as a rival to the Dreamliner, which was grounded last month after a lithium-ion battery on a Japan Airlines plane caught fire, while an All Nippon Airways flight was forced to make an emergency landing because of a battery malfunction.
These planes use lithium-ion batteries because they are relatively powerful compared to their size and weight. They are used for significant functions such as providing the starting and emergency power supply on the A350 aircraft.
Lithium batteries are also commonly used in other planes, but these are much smaller batteries, running much more minor things such as a small set of lights.
Shares in battery-maker Saft fell after the announcement. When it agreed the Airbus contract in 2008, it said it expected it to be worth 200m euros ($267m; £172m) over 25 years.