Bath extend front row duo's stay
Batty is one of the longest serving players currently in the Bath squad, having joined from Rotherham Titans in 2010.
Since his debut against Northampton Saints, he has made over 130 appearances in the Blue, Black and White.
Known for his dynamism and robustness in the No.2 shirt, the 29-year-old has put his speed to good effect this season scoring three memorable tries, including a spectacular 70 metre run-in against Cardiff Blues in the European Challenge Cup in December.
Fellow front row Lahiff has been a first team regular since his arrival from Australia at the start of 2015.
Adept on both sides of the scrum and a strong threat in the loose, the 27-year-old racked up 65 appearances over a four-year period for London Irish before spending time with Hawke's Bay in New Zealand and the Melbourne Rebels in Australia.
Hard-hitting and technically skilful, Lahiff ran out in Bath colours for the 50th time in the recent Premiership game against Newcastle Falcons.
The two forwards are the latest players to commit their future to the club after it was announced recently that Max Clark, Tom Homer and Rhys Priestland had all agreed new deals to stay in the West Country.
"We are extremely pleased to have agreed deals with two key players of the first team squad," Director of Rugby Todd Blackadder said.
"Ross and Max both bring a huge amount to the squad -as well as talented rugby players, they are energetic, hard-working, and have a really positive impact on and off the field. We are really looking forward to working with them over the coming seasons and seeing them go from strength-to-strength."