Boeing expects to finish testing its battery fix for the 787 within the next week or two. Then it will be up to the Federal Aviation Administration to decide when the planes fly again.

That assessment from Ron Hinderberger, Boeing’s vice president for engineering on the 787, was more cautious than statements from other company officials, who suggested Thursday that the 787 could be flying within weeks.

Boeing is testing several changes to the plane’s lithium-ion battery aimed at preventing overheating and a fire — conditions that led to the global fleet of 787s being grounded for the past two months.