Half a million Galaxy Note 7 smartphones without potentially explosive batteries will be available for exchange across the United States beginning Wednesday, Samsung said Tuesday.
Samsung said Sept. 2 that it was recalling all 2.5 million Note 7s worldwide and would replace them free because of a manufacturing defect that could cause their rechargeable lithium-ion batteries to catch fire or even explode while charging.
CNBC: After the Note 7, Here Are 10 of the Biggest Tech Recalls Ever
But the company couldn't implement a formal exchange policy for Note 7 owners in the United States until the Consumer Product Safety Commission announced a recall — which it didn't do until last week.
Samsung said Tuesday that 25 percent of the affected phones in the United States have already been exchanged voluntarily since the company's Sept. 2 announcement. The initial delivery arriving in stores Wednesday means about three-quarters of U.S. Note 7 owners will have exchanged their Note 7s or can do so immediately.
Owners who disregard the recall will get a software update that will pop up a reminder every time their phones are powered up or plugged in to charge, said Samsung, which said owners will be able to tell that they've got a new, safe phone because the color of the battery icon in their status bars — the information bar at the top of the screen — will turn green.
Related: What to Do If You Have a Recalled Samsung Galaxy Note 7
In the absence of the formal recall, Samsung had tried a variety of ways to get owners to stop using the flammable phones.
The company said last week that it would begin downloading a separate software update that wouldn't let Note 7 batteries charge past 60 percent, cutting the phone's battery life almost in half. At the same time, it urged users to turn off their Note 7s immediately and get them replaced — without clarifying how it could push the update to a phone if you've followed its advice and turned the phone off.
It's a murky but fast-moving story. Here's what you need to know:
How many phones have gone bad?
It's hard to say. In its recall last week, the CPSC update reported that there had been at least 92 incidents in the United States, including 26 reports of burns and 55 reports of property damage caused by fires in cars and a garage.
Those numbers encompass only formal reports made to the federal government. Other reports of similar incidents have continued since then — like a suspected Note 7-caused house fire in South Carolina and the Jeep that was burned out in St. Petersburg, Fla., after the owner left his Note 7 on its charger while he unloaded some shopping.
"Not the barbecue I wanted on my day off," the owner said.
What went wrong?
The battery in the Note 7 is a rechargeable lithium-ion unit in which charged atoms, or ions, of lithium move back and forth from the negative end of the battery to the positive end. The ions reverse toward the positive side when the battery's on its charging cord.
What happened with the Note 7 batteries — and only the Note 7 batteries, according to Samsung — is that during the manufacturing process, a fault got through that makes it possible for the positive and negative ends of the battery (called anodes) to come into contact with each other.
"If negative and positive sides of a battery combine, either due to a material failure or due to [a] defect in the cell assembly, it leads to short circuiting of the battery," said Vibha Kalra, a professor of chemical and biological engineering at Drexel University in Philadelphia.
And when that happens, you can get "overheating, and possible fire [or] explosion," Kalra said on Drexel's blog.
How hot can the phones get? Literally too hot to handle.
"A lady came in yesterday, and she couldn't even touch it when it was charging — like, physically is not possible to touch it," Tyler Childress, owner of The Cell Phone Guy in Sioux Falls, S.D., told NBC station KDLT. "She had to unplug it and let it cool down first.”
What's being done?
Other countries, like Canada, issued formal recalls weeks ago. In the United States, the Federal Aviation Administration, several airlines, New York's Metropolitan Transit Authority and New Jersey Transit have all asked passengers to keep their Note 7s turned off on passenger planes, trains and buses.
The major U.S. carriers — AT&T, T-Mobile and Verizon — all stopped selling the phone.
Can we use a different kind of battery?
That's the holy grail. Startups and giant companies alike are working feverishly to find the next generation of longer-lasting, smaller batteries for handheld devices.
Some rely on new materials, like silicon microwires, while others hope to put lithium to better use, perhaps by mixing it with the oxygen in the air we breathe.
For now, however, rechargeable lithium-ion technology is in the batteries used in almost every cellphone, laptop, tablet, camera and gaming device. That's because they're cheap, efficient and relatively safe and, crucially, because you can pack a lot of charge in a small package.
Nothing both better and safer has been able to make it to market. But while current technology is considered the safest available, that doesn't mean it's actually safe.
"The components used in [lithium-ion] batteries are inherently unsafe, so even a 'minor' manufacturing defect or battery abuse can be dangerous," said Kalra, the Drexel professor.
It's not like the issue isn't well known.
Non-rechargeable lithium-ion batteries are banned from being shipped as cargo on U.S. passengers, because just one bad battery can cause a rapid chain reaction resulting in an explosion. The phenomenon is called "thermal runaway," and it can also happen in cargo-loads of the rechargeable batteries in your phone.
The U.N. International Civil Aviation Organization temporarily banned rechargeable consumer batteries as cargo in February. The order wasn't binding on the FAA, which says it's closely monitoring whether it needs to ban them, as well.
What happens to Samsung?
For now, it has lost a lot of money — more than $14.3 billion through Monday as investors have hung up on the company.
For the future, it remains to be seen whether the Note brand can recover its luster.
"I can't think of a worse situation," said Sree Sreenivasan, the new chief digital officer for New York City and former technology reporter for NBC New York.
"They were hoping this was the best phone that's ever been released," Sreenivasan said in an interview on CNBC. "In fact, it's going to go down as one of the worst."
As for Samsung, itself, analysts generally told CNBC that it's big and nimble enough to sustain the damage.
And losses could extend far into the future. Samsung said that from now on, it will use batteries only from the Chinese company Amperex in the Note 7, Yonhap reported.
Samsung will now have to buy those batteries instead of using ones it made itself — which were in 70 percent of all 2.5 million Note 7s sold to date.
And procuring an adequate supply could be a problem — Amperex also makes batteries for Apple's iPhone 7 and iPhone 7 Plus, and it remains to be seen whether it can keep up with the demands of both giants.
