Momoe:
In the 'Good old days', the manufacturers bottomed out the cause of the problem and then carried on.
Following the Comet crashes, DH built a fuselage sized tank and ran endless pressurisation cycles, when the inevitable happened they gained an understanding of the cause.
Boeing tweaked some software parameters on the charging algorithms, built a steel box round the battery and carried on: Root cause of the problem still unknown.
'Good old days' not looking too shabby now are they?
So DH built a single test tank and waited a long time. Boeing has installed a test tank in each plane in the fleet. Sounds more efficient, right?
