Williams ran KERS without issues throughout Friday practice in Melbourne, as it reintroduced the device following the problems it had suffered in testing.
The team had been forced to disconnect its KERS for the final week of winter running amid reliability glitches, raising concerns that it might have to start the season without the energy boosting system. But Williams was confident that it had managed to identify and resolve its issues back at the factory, and had no further problems in Melbourne practice today.
Technical director Sam Michael said: "We successfully worked through our program, which included running all day with revised KERS components, testing aero modifications and a new front wing on Rubens' car. Everything worked as expected."
Rubens Barrichello was also pleased with how the KERS had performed, and felt the car had good potential as he took ninth place in the second session having been fifth in the morning.
"That was quite a straightforward day," he said. "We were able to run KERS throughout, which is only the second time that I've had it on the car. I think we showed some competitiveness today but we need to do some work to keep it up. I enjoyed my Friday so I'm looking forward to a good weekend."
His teammate Pastor Maldonado started his Formula 1 career with 18th place.
"It was a bit difficult this morning because I didn't know the track and so I spent most of the session just getting to grips with it," he said. "It was also quite slippery. This afternoon, we concentrated on long runs and were happy with the performance of the car. As we were good on the long runs, I think I can improve a lot tomorrow in terms of timed laps. I'm confident going into the rest of the weekend."