As Boeing activated the electrical system of its 787 for the first time last week, the airframer acknowledged that it was exploring a change to its power system for production aircraft due to longevity concerns.

Boeing will move away from its original lithium ion battery design for its main and auxiliary power units, flight-control electronics, emergency lighting system and recorder independent power supply. Instead, Boeing is investigating the incorporation of manganese inside the lithium ion battery to boost service life.

Boeing has not determined which 787 will be the first to receive the new battery modifications, although multiple programme sources have told Flight's FlightBlogger affiliate that the new battery could be introduced as early as Airplane Seven, the first production 787 scheduled for delivery to All Nippon Airways in the third quarter of 2009.

ANA 787

The sources add that the first six flight-test 787 aircraft will have the original feature lithium ion batteries, but will be retrofitted with new batteries before delivery to airline customers.

The use of lithium ion batteries is to be the first application of the technology on a commercial jetliner.

The US Federal Aviation Administration voiced its concerns about the use of lithium ion batteries in an April 2007 proposed special condition.

At the time, the FAA said that the 787-8 would have "novel or unusual design features" and required, "additional safety standards that the [FAA] administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards".

The FAA cited three specific safety concerns about lithium ion batteries, which included overcharging, over-discharging and the potential flammability of cell components.

Boeing underscores that the change in battery technology is unrelated to any safety concerns and the airframer is fully complying with the 2007 Special Condition.

Japan's GS Yuasa supplies the batteries for the 787 Dreamliner.

Source: Flight International