His four-year-old son Raul runs around him and Battisti, 62, seems marked by the nearly four decades he has spent on the run from murder charges in his native Italy.
The fugitive is wanted in connection with four killings -- including of two policemen -- attributed to a far-left extremist group active in the 1970s.
He has always maintained his innocence and says he is a victim of political persecution.
"The tension is high because if my case was based solely on jurisprudence, I would not be in this situation," he told AFP in an interview.
He spoke in Portuguese interspersed with a few words of French, at the house of a friend where he stays in the small seaside resort of Cananeia, near Sao Paulo.
In the humble living room of the house, the image of Marx hangs beside another of Argentine revolutionary Che Guevara, a Palestinian flag and a reproduction of Picasso's "Guernica," which depicts the bombing of the Spanish town in 1937.
Convicted in 1979 of being a member of an armed gang, Battisti escaped from a prison near Rome two years later and fled to France via Mexico.
Battisti has lived freely in Brazil for the last few years, but always under the threat of extradition demands from Italy, for whom he symbolizes the "Years of Lead."
That period saw political bombings, kidnappings and killings by extreme left wing and right wing groups in the 1970s and early 1980s.
Battisti was arrested on October 4th near Brazil's border with Bolivia and later released, but Italy has made a new push for him to be sent back to face justice.
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France was on the verge of handing Battisti to Italy in 2004 when he skipped bail and fled to Brazil, where he lived clandestinely until his 2007 arrest in Rio de Janeiro.
He then spent four years in custody until then-president Luiz Inacio Lula da Silva, on the last day of his mandate in 2010, decreed that Battisti should not be returned to his homeland.
The decision to free him sparked outrage in Italy.
Brazil's current president, Michel Temer, is believed to be more favourable to extradition, which Brazil's Supreme Court is due to consider from Tuesday.
Battisti, the author of several critically acclaimed novels, said Lula's decree cannot be overturned more than five years on, addint that there is also an "ethical question."
Battisti said he is "not sure" Temer is going to extradite him.
"It would surprise me that a president could annul a decree of one of his predecessors," he said in a calm voice, but with his eyes betraying a certain weariness ahead of the court ruling.
His partner, Priscila, a 31-year-old teacher and the mother of Raul, looks at Battisti with the concern that has been gnawing at her since his arrest at the Bolivian border on October 4th.
Police alleged he had undeclared cash worth several thousand dollars. The judge who ordered him initially detained said it appeared Battisti wanted to flee out of fear of extradition.
Battisti, whose lawyers got him released a few days later, says he was with two friends and just wanted to buy some fishing gear.
In his eyes, he was targeted at the border by authorities who "planned for months, in a big way, and with Italian support."
The incident led to a media storm that shook the tranquility of his life in peaceful Cananeia, a community of 12,000 where Battisti has lived for years.
Neighbours see him sipping wine beside the sea wearing a Corinthians jersey, Sao Paulo's celebrated soccer team.
"I feel as if I was born here," he smiled.
Battisti was convicted in absentia of having personally killed the two Italian policemen, of taking part in the murder of a butcher and of having helped plan the slaying of a jeweler who died in a shootout that left his
14-year-old son in a wheelchair.
"I have always said that I am guilty of participating in an armed group and of taking a position against a Fascist, mafia and thieving state," Battisti said.
"But they have to prove the crimes for which I have been condemned.
"The one thing that bothers me is the pain caused to my family," he said, mentioning the two daughters he left in France.
But for him, that is part of the struggle, "which is worth carrying out to improve people's lives, the poor, those who lack access to the world's riches."