Samsung SDI to supply more batteries to Tesla Samsung SDI is expected to account for about 8 percent of Tesla battery demand this year, worth 36 billion won. It expects to raise that portion to 40 percent in 2016, with sales to the American company rising to 254 billion won. "From next year to 2018, Samsung SDI may handle 40 percent of Tesla demand," said another source directly involved with the issue. Samsung SDI said nothing has been decided. Samsung SDI's target for EV batteries is considered as rather aggressive. But optimists say EVs remain economically-viable with gas at $2 per gallon. Even with plunging oil prices, analysts say the economics for EVs is well supported as they are still at parity with conventional vehicles after 5 years of ownership at the current gas price level. Tesla CEO Elon Musk expects to sell "a few million EVs a year by 2025. The company will soon start building two new factories, one each in Europe and Asia. To that extent, Tesla needs additional battery partners.