Tesla Motors Inc. has scheduled the grand opening of its battery factory outside Reno, Nevada, one of the cornerstones of the electric-car maker’s quest to become a mass-market manufacturer.

Tesla TSLA, +4.42% set the grand opening event for July 29 in an email to customers who, as part of a sales referral program, steered the most people toward buying a Tesla and won that perk, among others. A Tesla spokeswoman confirmed the message but did not provide other details about the ‘Gigafactory’ event.