They were hoping Tesla's technology would mark an even bigger leap forward and propel the company's soaring stock to even greater heights.
Musk raised those worries with a series of tweets Monday warning that Tesla's new battery technology might not be ready for high-volume production until 2022.
Musk reiterated that timetable during Tuesday's showcase and then added it might take up to three years before the battery technology translates into a new Tesla model selling for $25,000.
Besides lowering the price, Musk promised the new battery technology would help Tesla reduce the size of its vehicles by about 10% and extend their range by 56%.
That projection implies the Tesla cars using the new batteries will be able to travel 500 miles (800 kilometers) or more on a single charge, surpassing the distance many gas-combustion cars can traverse before needing to refuel.