The three-day Taliban ceasefire ended on Sunday.
Provincial governor Abdul Qafoor Malikzai said the Taliban attacked two security posts in the early hours. Abdul Aziz Bek, head of the Badghis provincial council, said one military base was targeted, in the district of Balamerghab.
"Large numbers of Taliban came from several directions," Bek said. "After hours of heavy fighting 30 Afghan security forces were killed and the Taliban captured the base."
Fifteen Taliban terrorists were killed in other areas of the province overnight, he said, adding that the terrorists prepared their attacks and did reconnaissance of the area during their ceasefire.
The Taliban did not immediately comment on the attacks.
Naqibullah Amini, spokesman for the Badghis police, confirmed the death of 30 soldiers and said the Taliban killed four soldiers in separate attacks on security checkpoints in the same district.
President Ashraf Ghani extended his unilateral ceasefire, initially due to end on Wednesday, by 10 days.
Some have criticised his ceasefire, which allowed the Taliban to freely enter government-held areas, including the capital, Kabul.
"The consequences could be disastrous," a senior Western diplomat in Kabul said this week.
The Taliban are fighting to oust U.S.-led NATO forces combined and defeat Ghani's U.S.-backed government to restore sharia, or Islamic law, after their ouster by U.S.-led forces in 2001.