Electric car maker Tesla Motors announced on Sunday, Jan. 1, that it was extending its free unlimited charging for all Tesla Model S and Tesla Model X vehicles ordered on or before Jan. 15. Tesla earlier said that the free unlimited charging offer was only valid on vehicles ordered before Jan. 1.

In November 2016, Tesla made its first announcement that customers who ordered cars after January 1, 2017, would no longer receive the free Supercharging credits enough for about 1000 miles of driving. Today, Tesla is extending its free supercharging offer until January 15, 2017, giving prospective buyers another two weeks to enjoy unlimited supercharging, according to The Verge.

After the Jan.15 date, Tesla's new plan announced that last year will come in full effect giving new buyers 400 kWh a year of free Supercharging credits, good for roughly 1,000 miles of driving. At this time, it's still unclear how much Tesla plans to charge its future customers for charging their Tesla vehicles. It's said to depend on local electricity rates.

Tesla's Biggest Challenge Finally Emerged

Tesla may have its worst nightmare this year. According to TechCrunch, Tesla might experience trouble with its current supply of battery.

The next decade is poised to make a major technological disruption in the energy storage and the entire electric (EV) industry. A new supply chain is emerging fast and the development of reliable sources of raw material becomes critical.

In particular, the EV industry needs batteries to maintain power and suppliers are just starting to fully appreciate the supply for critical rare Earth minerals. Before, Lithium received much of the industry's attention, but a new supply chain is emerging fast and is slowly taking over the industry -- cobalt.

Cobalt, a critical metal for Lithium-ion cells battery, has many diverse industrial and military applications and the battery industry uses nearly 42 percent of the entire cobalt production. Unfortunately, there is not much cobalt supply around and the race to secure cobalt supply is already on with Chinese companies currently leading the race.

That's where the problem lies. Elon Musk ambitiously plans to produce 500,000 electric vehicles a year by 2018 and the prospects of making it a reality seem far-fetched. China is moving fast and it successfully secured a dominant position in controlling global cobalt supply for local consumption. This could make the life a little bit harder for Tesla. "A la Chinoise" what some analyst called it.

Tesla is entering a new age, the era of supply chain transparency. An era where Tesla may not have the chance to outrun its adversaries.