In January 2011, the group began to work on their second studio album. The album featured writing credits from the band members on ten of the fifteen tracks, and contributions from Steve Mac, Wayne Hector, Ed Drewett, Diane Warren and Guy Chambers. The album's lead single, "Gold Forever", was released in aid of Comic Relief and debuted at number three on the UK Singles Chart. In July 2011, the group released the album's second single, "Glad You Came", which became their second number-one single. It was number one for two weeks, and stayed in the top ten of the chart for six weeks. The single also reached number one in Ireland and remained there for five weeks. The song also charted in some European territories, and was very successful in Australia. The third single from the album, "Lightning", was released on 16 October 2011, peaking at number 2 in the UK and number 5 in Ireland. The fourth single, "Warzone", was released on 26 December 2011, with the music video and radio debut coming in early November 2011. On 7 November 2011, the group's second album Battleground was released. It debuted at number 5 in the UK and number 4 in Ireland. It has since been certified Platinum in the UK. In addition to shows in the United Kingdom, including T4 on the Beach, V Festival, and the iTunes Festival, the group supported Canadian singer Justin Bieber in Brazil on 8 and 9 October 2011 and Britney Spears on her Femme Fatale Tour at the Manchester Evening News Arena on 6 November 2011.