In moving up from San Diego into a 27,000-seat stadium in Los Angeles, the Chargers were hoping to offset a smaller fan base with an unusually intimate atmosphere, one in which the supporters they did draw could make their presence felt.

Unfortunately for the Bolts, fans are certainly having an impact on the team’s games in its new home, but they have largely been fans of the other team. The latest and most glaring example came Sunday, when green-clad Eagles supporters invaded the StubHub Center, putting the home team in the position of getting audibly booed from the moment it ran onto the field for the game.

Of course, given that the Chargers came into the game 0-3 on the season, and that their eventual loss Sunday (26-24) would give them nine straight going back to last season, the NFL’s longest active losing streak, it’s conceivable that more than a few of their own fans were doing some booing. However, there was no mistaking the fact that the overwhelming majority of people in attendance Sunday were there to root for the Eagles.

Reuben Frank, an analyst for CSN Philly, reported, “Just did a lap around the concourse. Legitimately 75-80 percent Eagles fans here. And they are loud and obnoxious and it’s so great.”

A fan at StubHub who was wearing a Chargers jersey described the situation Sunday to USA Today as “nauseating.’’ He added, “Everybody knows we’re not wanted here. L.A. doesn’t want the Chargers.’’

After 55 years in San Diego, the Chargers’ ownership decided that its long-standing impasse with local officials over the construction of a new stadium was too much to bear anymore, so it decided to join the Rams at what will be a state-of-the-art stadium in Los Angeles. However, that facility won’t be ready until 2020, leaving both teams to play elsewhere in the area for three seasons.

The Rams aren’t exactly filling up the Los Angeles Coliseum since returning from St. Louis last year, but then again, it has a capacity of over 93,000. Having played in Los Angeles from 1946 to 1994, the Rams were able to maintain a solid fan base there, whereas the Chargers are associated with a rival city to the south.

In fact, the Chargers have had the option to add 3,000 seats at StubHub Center, which was built to be the home of MLS’s Galaxy, but they are opting not to do so for at least this season (per Pro Football Talk). If they want to expand the seating for next year — or to simply avoid a season that appears increasingly disastrous — the Chargers will need to quickly turn things around and give fans in their new city something for which to cheer.

“People aren’t going to pay 180 bucks for tickets, 40 bucks for parking, eight bucks for a beer and watch you lose,’’ a Los Angeles-area fan told USA Today. “Then you walk into Staples Center [home of the Lakers], and there are how many championships?’’

Read more from The Post: