Boeing has said that a test flight to check the 787 Dreamliner's new battery system "went according to plan", BBC News reported.

Boeing redesigned its battery after malfunctions on some planes led to the grounding of the entire 787 fleet.

The firm said it will analyze the data and prepare for another test flight aimed at demonstrating the system to regulators in "coming days".

According to some estimates, Boeing is losing $50m per week due to the grounding of the 787 planes. The grounding has also led to Boeing being prevented from delivering new Dreamliners to customers.

The Dreamliner 787 is the first plane in the world to use the lithium-ion batteries, which are lighter, hold more power and recharge more quickly. But incidents relating to battery malfunction earlier this year raised some concerns over its safety and led to the grounding of the fleet.

In January, a fire started in a battery pack in a Japan Airlines 787 in Boston. Meanwhile, an All Nippon Airways flight was forced to make an emergency landing because of a battery malfunction.

Boeing has since submitted a plan to the authorities to redesign the battery to ensure its safety. Its plan includes improving the battery design to stop faults from occurring as well as enhancing the production, operating and testing processes.

At the same time, Boeing said the plan included a new battery enclosure system to prevent any possible overheating from affecting the plane.