Young entrepreneur Nadya Nguyen and her three partners at HidrateMe, have discovered that entrepreneurship is not an easy drink of water.

Nguyen, 24, a University of Minnesota graduate, suffered from headaches during her school days, until a medical-school friend suggested she drink more water. Nguyen, a busy, intense young woman who also had to work during school, tried to hydrate more and get more rest.

The experience also sparked a business idea.

Nguyen and three classmates, including an engineer and a designer, invented the Hidrate Spark “smart” water bottle (hidratespark.com), including a sensor that tracks water consumption, lights up when it is time for more and connects to an iPhone. Each owner programs the system with an iPhone application, including height, weight, activity levels, heat and humidity.

The team in 2015 was selected for the three-month “Sprint Mobile Health Accelerator powered by TechStars,” including a $120,000 award. HidrateMe also raised a more-than-planned $600,000-plus with a Kickstarter campaign. The bottles went into production through a Chinese factory in 2016.

“There were a lot of hiccups,” Nguyen conceded last week.

“I received a few e-mails last year complaining about defective bottles and delays from readers of a 2015 story about HidrateMe.

“We produced 17,000 bottles between December 2015 and April 2016,” Nguyen said. “We learned that right in the middle of that period, there was Chinese New Year. People take off the entire month of February.

“We shipped our first production batch between May and June, and it ended up being a much-bigger challenge that we anticipated.”

Nguyen said problems were compounded by issues at a third-party San Francisco distribution warehouse, which it has since dropped.

The management team spent weeks last spring and summer working around the clock, shipping bottles to customers from the apartment of fellow founders Alexander Hambrock, a university-trained engineer, and Cole Iverson.

“It’s never been easier to take your garage invention and turn it into a business,” Hambrock said in 2015 before the problems hit.

The founders realized how wrong he could be last year.

Nguyen said last week that amends to jilted customers and late deliveries have been made. Hidrate works with a new distributor and achieved better results with the factory, after several visits to China.

“We leave nothing to ambiguity,” Nguyen said. “Everything is very clear.”

A second order was produced in December without a hitch and third order goes into production late this month, she said.

“We had customer complaints that we used to fix the products for the second batch,” Nguyen said. “We took four months between the first batch [last spring] to the second to fix a ‘connectivity’ issue and the [defect] rate was higher than expected with the first batch.

“We fixed the hardware so the connectivity is faster and consistent and doesn’t drop out when connected to your phone or Bluetooth,” she said. “The people using the second version of the product are happy. The defect rate in the second batch was lower than expected. And we’ve doubled the amount of LED lights inside the sensor stick, inside the bottle … from two to four. So red and white in the [Hidrate Spark] can be seen even in the light of the sun.”

Customer satisfaction has improved for the iPhone application from 2 stars a year ago to 4.5 stars, Nguyen said.

The bottle, which sells for $54, less a $7 online coupon, should bring in $500,000-plus in revenue this year, Nguyen said.

Nguyen said the four partners still pay themselves minimum wage. And no overtime pay.

Neal St. Anthony has been a Star Tribune business columnist and reporter since 1984. He can be contacted at nstanthony@startribune.com.