The company said it ended the quarter with $3.2 billion in cash after spending $655.7 million in quarterly capital expenses.
"Elon Musk famously said they wouldn't need to raise money by the end of the year. I'm on record as saying I believe they definitely will," Barton said.
"I think they're going to put it off until the last possible second. They have a large debt obligation in March of 2019 and I think they'll have to raise well before that. I'm expecting towards the end of this year," he said. "It's going to have to be north of $1 billion dollars, a billion and a half, and if they have to go to the debt markets for that — it's going to be very expensive paper."
Other analysts have said a raise could come as soon as this quarter.
"We think they're going to raise cash this quarter. We think they're waiting until after this earnings print," Gordon Johnson, an analyst with Vertical Group Research, told CNBC's "Closing Bell."
The lack of Model 3 revenue has exacerbated Tesla's cash burn as the company continues to spend on its assembly line and prepares for new investments on multiple projects in the pipeline.
—CNBC's Robert Ferris and Lora Kolodny, and Reuters contributed to this report.