Tesla has been fighting a lone battle in the EV war, but that will soon change as major automakers with big budgets like Volkswagen and Mercedes-Benz and even Porsche are about to unleash an army of electric cars that could pose a serious threat to the automaker. Mercedes recently announced a $1 billion investment to expand its Alabama plant where the EQ crossover will be built. This seemed like a paltry investment which left CEO Elon Musk decidedly unimpressed- but this was only half the story.

Responding to a Tweet by USA Today which alerted the CEO about the investment, Musk's response was predictably cutting. "That's not a lot of money for a giant like Daimler/Mercedes," he said. "Wish they'd do more. Off by a zero." To be fair, the Tweet sent by USA Today was rather provocative. "Mercedes makes $1B bet it can take down Tesla," the Tweet read. Mercedes's response? The German automaker was quick to fire back at Musk, confirming in a reply on Twitter that $1 billion is being spent on battery development, while another $10 billion is being used to develop a range of next-generation EVs. "You're absolutely right @elonmusk. Here the missing zero," the Tweet read.

The $10 billion investment will help Mercedes add as many as 10 EVs to its line-up by 2022 as part of its new EQ sub-brand, which was previewed at this year's Frankfurt Auto Show with the EQ A Concept. The first is due to roll out in 2019, so targeting 10 by 2022 is very ambitious. Such a large investment is certainly justified. Musk seemed surprisingly pleased with Mercedes' response, simply replying "good." If anything, he encourages competition in the segment and for automakers to invest more money into electric car development. He obviously still wants Tesla to succeed, but his vision isn't to dominate the EV market, but to embrace it.