The results have not been released, however. Tuesday, investigators plan to test the battery charger and download memory from the battery's controller.
The National Transportation Safety Board also revealed that not all of the planes' problems have been the same. In one case, the battery was overcharged, but in another case, it was not.
Transportation Secretary Ray LaHood says the planes won't fly again until regulators can be certain the aircrafts are safe, and this latest news is likely to delay the Dreamliner's return to the skies.