LOS ANGELES — Wednesday Apple admitted that it deliberately slowed down older iPhones to prevent unexpected shutdowns when the batteries were worn out.

Thursday, the lawsuits began. And Friday they continued.

A proposed class-action breach-of-contract suit was filed by two consumers, via a Los Angeles lawyer, saying they never consented to allow Apple to slow their older iPhones.

More:Meet Mt. Juliet teen who showed how Apple slows down old iPhones on Reddit

The second suit, filed in Chicago on Friday, asks for $5 million in damages on behalf of four consumers, "because tens of thousands of similarly situated putative class members," were tricked into purchasing newer model iPhones based on Apple telling consumers they needed the latest iPhones for better speed and performance, the suit said.

Apple didn't respond to requests for comment about the lawsuit.

On Wednesday, it had put out a statement confirming what many users had suspected — but couldn't verify — that iPhones slowed as they aged. New to iPhone owners was the explanation: Rather than just a reflection of age, the slowing was deliberate, an after-effect of software designed to prevent blackouts.

"Lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, have a low battery charge or as they age over time, which can result in the device unexpectedly shutting down to protect its electronic components," Apple said. "Last year we released a feature for iPhone 6, iPhone 6s and iPhone SE to smooth out the instantaneous peaks only when needed to prevent the device from unexpectedly shutting down during these conditions.

In a nutshell, Apple's iOS mobile operating system is designed to avoid unexpected shutdowns on older phones and this, in turn, can slow the phones. Apple had said last year it had released a fix to help avoid such blackouts. But its failure to disclose that this solution could slow down the phone, which may have prompted some owners to decide to scrap their old phone and buy a new one, has raised the ire of some consumers.

iPhones, like many recent Android devices, do not have batteries that can be easily replaced by users. But they can be replaced. Apple charges $79 for a new battery for those without its AppleCare warranty protection, a cheaper cost than several hundred dollars for a new device. The newest iPhone, the iPhone X, starts at $999.

If you're curious about the status of your phone's battery you can download a free app, such as Battery Life from developer RBT Digital or head into your local Apple Store to get it checked out.

Tennessee teen

The issue came to light when a 17-year-old Mt. Juliett, Tennessee teen's post on the social media website Reddit questioned why he should have to buy a new iPhone to speed it up.

Tyler Barney, a high school student and tech aficionado in the Nashville area, also known by the username TeckFire, posted on the popular message board website that he believed he'd discovered why Apple phones slow down with age.

After troubleshooting the issue and using a number of apps to measure the performance of his personal iPhone 6s, Barney discovered his phone slowed down after downloading Apple's operating system iOS 10.2.1.

"It became buggy. That's the best way to put it," Barney was quoted in a news release his uncle Rob Blevins sent out to news outlets Friday. "It was a big mess all the time. Even typing was painful. Seconds passed between keystrokes."

Barney assumed the next updated operating system release by Apple would bring his phone back to life. In the meantime, he tried his brother's older model iPhone 6. Still, he said his brother's phone, which had an inferior processor but was a year newer, was much faster.

Barney turned to the Internet, where some suggested he replace the battery. He did this and his phone sped back up, so he concluded the decreased performance was due to the phones lithium-ion batteries.

Barney then took to Reddit, via his username TeckFire, to share his findings and that's when the post went viral.

And that's how a 17-year-old disrupted the Internet this week.

Follow USA TODAY's Jefferson Graham on Twitter, @jeffersongraham

Contributing: Eli Blumenthal and the Tennessean