Discharging the battery too quickly, or with too low voltage, can also cause it to overheat, said University of Dayton professor Raul Ordonez, an aircraft electrical and computer engineer who spent time observing Dreamliner development at Boeing's Seattle headquarters.
Investigators in Washington have taken X-rays and CT scans of the lithium-ion battery that caught fire in Boston, the safety board said. They have also dismantled the battery and examined some of its individual cells.
The agency said it has also examined several other components from the plane, including wire bundles and battery management circuit boards.
"The fact that the NTSB is basically looking at every component around the battery, including the computer hardware and the (memory) software, means that they have no idea yet about a culprit and (they) suspect everything," Ordonez said.
Whatever the fix, Schiavo said any changes other than minor will require at least some re-engineering which will in turn require FAA approval. Both of those can result in a "slow process taking months, depending on the extent of engineering changes."
Boeing is using the lithium-ion batteries to electronically assist some of the functions that were previously performed using hydraulics. A lighter plane is more fuel efficient, which is one of the 787's main selling points.
There is no need to drain lithium-ion batteries fully before recharging, meaning less maintenance, though they can catch fire if overcharged.
Airbus uses lithium-ion batteries to power some systems aboard its A350 airliners. A spokeswoman said in a statement to CNN that Airbus "will carefully study any recommendations that come out of the 787 investigation and evaluate whether they apply to the A350 XWB," a new airliner still being developed by Airbus.
"Boeing was very, very lucky there was no catastrophic event," said Schiavo. "But, the luckiest of all is Airbus ... now they can make the fixes [to the A350 XWB] without the public relations hit Boeing has taken."
Boeing said Friday it will not deliver any Dreamliners to its customers as it works with the FAA over the battery concerns.
"We need to get the bottom of this," said Goglia. "We need to get comfortable with flying these airplanes again."