To campaign for former vice president on National Voter Registration Day, Mr Obama said the stakes of the 2020 election are much bigger than "Joe or the man he is running to replace".
"What's at stake is whether or not our democracy endures," Obama said in the video. "And the folks in power are hoping that you stay at home."
It is a repeat message from Mr Obama’s speech at the Democratic National Convention, where he said that man Mr Biden is trying to replace, Donald Trump, was a threat to democracy and rule of law.
“No one, including the president, is above the law,” Mr Obama said on the convention's third night.
"Embrace your own responsibility as citizens — to make sure that the basic tenets of our democracy endure Because that’s what’s at stake right now. Our democracy,” he continued.
Mr Trump responded to Mr Obama's DNC speech on Twitter, saying "he spied on my campaign and got caught!"
The president repeated that response at a campaign rally in Ohio on Monday, where he accused Mr Biden of treason and issued a veiled threat of legal action against the previous administration.
“You know they spied on my campaign, we caught ‘em. And by the way, that’s Biden that’s Obama. They spied on my campaign, it’s never happened before, it’s treason,” Mr Trump said.
“[James] Comey and all the sleaze bags, they spied on my campaign and we caught ‘em. Let’s now see what happens, I stay out of it, I just stay, I’m trying like hell to just stay out of it. I don’t have to actually but it’s better if I do I think.”