Tesla's battery supplier was surprised by Musk's cost-cutting actions.

SMM: Elon Musk of Tesla has cast an uncertain shadow over the sales prospects of its Asian suppliers after announcing measures to reduce the cost of electric vehicle batteries and hinting that it will eventually start producing its own batteries.

LG Chemical fell 5.5 per cent in Seoul, 4.7 per cent in Shenzhen in Ningde era and 4.3 per cent in Tokyo by Panasonic. According to Bloomberg's supply chain analysis, the world's three largest electric vehicle battery makers all supply Tesla.

Mr Musk, chief executive of manufacturers of Model S, X and 3 models, said in a tweet that Tesla still needed to buy additional batteries from the three companies, but that if he did not start producing their own batteries, there would still be a "serious shortage" by 2022.

Speaking at Battery Day at Tesla's plant in Fremont, Calif., Mr. Musk said the company plans to build an electric car that costs $25000 in about three years. The price difference with the company's cheapest model ($37990) can be achieved by halving the cost of the battery, the most expensive component of electric vehicles.