TOKYO — An investigation into a lithium ion battery that overheated on a Boeing 787 flight in Japan last month found evidence of the same type of “thermal runaway” seen in a similar incident in Boston, officials said today.

The Japan Transportation Safety Board said that CAT scans and other analysis found damage to all eight cells in the battery that overheated on the All Nippon Airways 787 on Jan. 16, which prompted an emergency landing and probes by both U.S. and Japanese aviation safety regulators.

They also found signs of short-circuiting and “thermal runaway,” a chemical reaction in which rising temperature causes progressively hotter temperatures. U.S. investigators found similar evidence in the battery that caught fire last month on a Japan Airlines 787 parked in Boston.

All 50 Boeing 787s in operation are grounded.

WASHINGTON, Pa. — Workers at Washington Hospital have voted to ratify a three-year contract, avoiding a threatened strike.Service Employees International Union Healthcare PA said an agreement was reached during a 30-hour bargaining session last week. The union had voted to strike if they could not reach an agreement.The union's current contract with the 274-bed community hospital about 20 miles southwest of Pittsburgh had expired last month.The contract had passed by a 92 percent approval among the 400 workers.

DETROIT — Consumer Reports is warning car buyers that turbocharged engines may not deliver the speed or fuel economy they expect.The magazine said that its tests showed turbocharged models from Ford, Hyundai and Kia are less efficient than competitors. It also said the turbocharged Chevrolet Cruze got little extra power or fuel economy.The magazine praised a turbocharged four-cylinder from BMW.Turbochargers pump extra air into engines to boost power. Carmakers charge more for them, promising extra power.

WASHINGTON — President Barack Obama has signed into law a bill raising the government's borrowing limit, averting a default and delaying the next clash over the nation's debt until later this year.The legislation temporarily suspends the $16.4 trillion limit on federal borrowing. Experts say that will allow the government to borrow about $450 billion to meet obligations.The Senate gave the bill final approval last week and sent it to Obama, who signed it Monday after returning from Minneapolis.Democrats and Obama had warned that failure to pass the bill could set off financial panic and threaten the economic recovery.The bill includes a provision attached by House Republicans that temporarily withholds lawmakers' pay in either chamber that fails to produce a budget plan.