How to safely charge and store lithium drone batteries

By Signe Brewster

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Although flying a drone might sound like the biggest risk in operating one, dealing with the batteries is potentially more explosive. At the 100 hospital emergency rooms that report electronics-related injury cases to the US Consumer Product Safety Commission, more than 200 incidents (PDF) involving drone batteries, stemming from fire, smoke, and explosions, were recorded between 2012 and 2017. Not every drone-battery incident results in an injury, but each pilot and expert I interviewed had a story about an exploding or fiery lithium battery going off especially after it had repeatedly crashed to the ground inside a drone. “When the batteries go, it’s like a little bomb,” drone pilot and HubHobby employee Brandon Reinert said. “It’s usually pretty spectacular.”

The most common type of battery that powers racing and photography drones is lithium-polymer, or Li-po, a kind of lithium-ion battery that packs more energy storage into smaller spaces. To find out how to reduce the risk of a spectacular battery failure and get drone batteries to last longer and perform better, I spoke to battery and drone experts about the right way to charge, use, and care for them.


Although inexpensive batteries and chargers like these are tempting to buy, it’s safer to invest in higher-quality versions to avoid a fire. Charging outside can also cut down risk. Photo: Signe Brewster

Charging is the most likely time for a drone battery to catch fire, so concentrate the bulk of your safety efforts there. According to the CPSC, more than half of the drone-battery incidents documented at hospital emergency rooms occurred while the drone was charging. Be particularly careful when charging batteries from a brand you’re not familiar with. “I would just assume the cheaper ones are going to catch fire at some point,” battery expert and Cadex Electronics product line manager Greg Funk said. “I wouldn’t treat it like a cell phone and plug it in overnight and go upstairs to bed.”

If you can, charge your batteries outdoors. Instead, Funk suggested, the single safest way to charge a drone battery is to do it outdoors. That’s the only place you can be sure it isn’t near anything else that can catch fire. An exploding battery also gives off toxic gases, which can be dangerous in an enclosed space. Just be sure to keep the batteries out of the sun so they don’t overheat, and away from dried-out plants or other combustibles.

If you have to charge indoors, set up fire-containment measures just in case. Many pilots, like Brandon Reinert, choose to charge indoors and take fire-containment measures. If you can’t charge outdoors, you can use any of a few different setups. Simon Cheng and Megan Proulx, who host the YouTube series Til Drones Do Us Part, charge batteries inside cinder blocks and keep a bucket of sand nearby to extinguish flames. The team behind FliteTest, another YouTube series on drones, suggests similar methods that use cinder blocks or an unsealed ammo can. If you must charge indoors and you choose one of these methods, make sure the setup isn’t near anything else that can catch fire. Never seal a battery inside a fireproof container; all that energy needs to go somewhere, and sealing it off will just cause the container to explode. That’s why good fire containment focuses on aiming flames and gases in a safe direction and then getting sand or water (yes, as Funk told us, you can extinguish a battery fire with water) on it as fast as possible.


Store batteries at around half their capacity to give them a longer lifespan. Photo: Signe Brewster

Drain batteries before storing them in a safe, temperate place. Store the batteries at or near room temperature in a location where you would spot a potential fire. If you have a healthy battery that isn’t overheating and has no punctures or puffing, it should be safe to store, but spontaneous battery fires do happen. DJI, which sells well over half of all personal drones in use today, recommends that if you don’t plan to use a drone for 10 days or more, discharge its battery to 40 to 65 percent of its capacity. A partial discharge reduces stress on the battery and helps give it the longest possible life, according to Cadex testing. Check your battery manufacturer’s recommendations for discharging, which will prevent the battery from degrading.


Keep batteries from knocking around during transport, whether you’re driving to a park or flying on an airplane. Photo: Signe Brewster

Keep batteries padded and secured in transit. As long as you monitor, charge, and store your batteries appropriately, they should be okay to transport without any extreme safety measures. Keep them secured in a place where they won’t bump around too much. Our guide to the best drone accessories has the backpacks we like best for transporting drones and their batteries.

Pack your drone and its batteries in your carry-on baggage for a flight. If you plan to take a drone on an airplane, read up on the FAA’s current rules (PDF) for batteries. Generally you can pack a lithium battery into a checked bag if it’s installed in a drone, but you can’t check spare batteries. Regardless, it’s a good idea to keep a drone with you while you’re traveling, to avoid losing it—so count on keeping your batteries in your carry-on luggage.


Drone-battery makers such as DJI usually recommend a flying-temperature range to protect batteries. Photo: Signe Brewster

Just as drone pilots have stories about charging batteries lighting on fire, many have stories about a crashed drone smoking or catching fire. Draining a battery too fast or crashing it into the ground inside a drone can cause the battery to fail dramatically—or simply to suffer from a shorter lifespan.

Avoid flying in extreme temperatures. To give batteries the longest life possible, follow the manufacturer’s instructions for flying, which should include a safe temperature range and a lowest acceptable discharge level. DJI, for example, recommends you fly drones in temperatures ranging from -10 °C to 40 °C (14 °F to 104 °F)—a range similar to that suggested by many other drone brands.

Don’t drain the battery too fast. Flying at full throttle for long periods—which can be preferable for some flying purposes, such as racing and agility—can also drain batteries so fast that they enter a dangerous process known as thermal runaway, where the materials inside the battery heat up and cause chemical reactions that prompt the battery to heat up even more.


Dispose of a cracked or puffy battery at a qualified waste center. Photo: Signe Brewster

Before and after flying a drone or charging a battery, take a moment to inspect the battery. If your drone’s battery has any visible damage or is puffing out, you need to dispose of it. However, not every battery will show physical signs of damage. The pilots behind FliteTest recommend using an analyzer like the HobbyKing HK-010 to see a readout of the state of each cell in the battery and catch problems before they become more serious. A battery is marked with a voltage—say, 3.7 V—which should be consistent across all of its cells. Over time they might begin to get out of balance, something that some chargers can correct for to some extent. Cadex’s Greg Funk recommended retiring any batteries in which the cells are out of balance by more than 0.1 V (100 mV), because it’s a sign that some cells are weaker than others.

“These packs are prime candidates for overheating and possible fire as the individual cells can be taken outside their safe operating range during charge and discharge,” Funk said.

Disposing of a damaged battery

Not every battery-disposal center has the facilities to handle damaged batteries. Photo: Signe Brewster

Research your options for battery disposal. Look at a site such as Recycle Nation or your county’s website to find a drop-off center that accepts household hazardous waste. Check whether the collection center accepts batteries and then give the folks there a call to confirm that they will take a damaged battery—not all places will. Before turning the damaged battery in, be sure to discharge it as close to 0 percent as possible to decrease the chance of fire.

Picking a drone battery and charger

Although the steps we’ve outlined can help you avoid disaster, you can save yourself a lot of trouble by choosing the right batteries in the first place. On the Internet you can often find batteries and chargers for sale with little known about who makes them and who sells them, and some of these sketchy options carry an increased risk of fire. Batteries with lower-quality materials or corner-cutting designs are more likely to catch fire when crashed or when charged and discharged at high speed, as is common with drone batteries.

Look for safety certification and features. As tempting as it is to buy the cheapest batteries possible, Cadex’s Greg Funk told us he recommended looking for batteries that are IEC 62133 (or equivalent) and UN38.3 certified to verify they are safe to use. Not every battery listing says whether it has the certifications, and sometimes you have to go digging through a manufacturer’s website to find the certifications.

Battery makers sometimes strip away extra safety features—forgoing a hard-plastic shell in favor of a simple soft-plastic wrapping, for example—to make budget batteries weigh and cost less. We strongly recommend that you look for brands with such extra durability features or other noticeable safety features, even if they cost a little more.

Opt for a programmable battery charger. Just as it’s important to choose the right batteries, take care to choose the right charger. As drone pilot Oscar Liang writes, a programmable charger is worth the extra cost because it will allow you to perform more battery-management tasks, such as checking that the battery is charging and discharging as designed, and discharging it completely before storing it. Greg Funk also recommended using chargers made by the same manufacturer as the battery.

All drone batteries, from the cheapest no-name brands to more sophisticated ones made by drone manufacturers, can benefit from extra care to keep them effective and safe.

A note about DJI batteries

DJI’s batteries cost more but tend to have more safety features than cheaper drone batteries. Photo: Signe Brewster

DJI drones are designed to work with the company’s own “Intelligent Batteries.” These batteries are more expensive than batteries for more basic drones, and because there are no authorized third-party batteries for DJI models, it can feel like the company is trapping you into buying its fancy batteries. But its batteries do have some built-in safety features and functions that provide extra protection compared with more basic batteries in less expensive drones or, in some cases, unlicensed replacements. According to engineers on the battery team at DJI, the company’s batteries include measures such as the ability to prevent overcharge or over-discharge and the ability to monitor the battery’s remaining capacity. Still, DJI batteries will degrade if you treat them poorly. Refer to DJI’s battery care instructions and follow the same care guidelines you would for other drone batteries.

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There's a bug stopping some iPhone XS and XS Max phones from charging

The brand new iPhone XS and XS Max devices have a weird charging error.
The brand new iPhone XS and XS Max devices have a weird charging error.
Image: mashable

Some iPhone XS and iPhone XS Max owners are having trouble charging their devices.

Owners across the web are complaining that some of Apple’s latest iPhones are not charging properly when plugged in, MacRumors pointed out Saturday. The problem seems to occur when users plug in their phones while they are in sleep mode and the screens are off.

YouTuber Unbox Therapy was alerted to this problem and performed a test where he plugged in a bunch of iPhone XS and XS Max devices to test whether they charge while asleep, and found that several XS and XS Max phones didn’t start charging until after he woke up the phone. Not only that, one iPhone XS Max was stuck in sleep mode while plugged in and he couldn’t take the phone out of its frozen state until he unplugged it.

Here’s how it looks:

Unbox Therapy tested all of the phones using a regular wall charger and noted in the beginning of the video that he hasn’t had a problem with a wireless charging block.

The issue may stem from a security feature introduced before iOS 12 came out that prevented iPhones from connecting to devices like computers if they haven’t been unlocked recently. That way a phone can’t be compromised as easily.

This shouldn’t be occurring when plugging a phone into a wall charger.

Apple did not immediately respond to a request for comment or a question about whether a fix will be coming soon. Hopefully it’s a software issue that can be fixed with an update.

In the meantime, make sure your iPhone XS or XS Max is not in sleep mode when you plug it in or else you may not actually be charging it.

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In the Dead of Night, Trump Administration Moves Hundreds of Migrant Kids to a Desert Tent City

Photo: Joe Raedle (Getty Images)

To deal with the burgeoning number of undocumented migrant
children in federal custody, the Trump administration in recent weeks has been awakening
hundreds of kids in the middle of the night at homes and shelters across the
country. Then, they are placed on buses and sent
to a tent city in the desert
in Texas, near the Mexican border, The New York Times reported.

According to the Times:

Until now, most undocumented children being held by federal
immigration authorities had been housed in private foster homes or shelters,
sleeping two or three to a room. They received formal schooling and regular
visits with legal representatives assigned to their immigration cases.

But in the rows of sand-colored tents in Tornillo, Tex.,
children in groups of 20, separated by gender, sleep lined up in bunks. There
is no school: The children are given workbooks that they have no obligation to
complete. Access to legal services is limited.

The move is part of a “mass reshuffling” that has relocated
more than 1,600 kids to the desert tent city so far, the Times said. The camp can hold about 3,800 kids after a recent
expansion. While there, they can spend months waiting for the process to play
out on their immigration statuses. According to experts, protracted custody can
lead to anxiety, depression, violent outbursts, and escape attempts, the report

The number of undocumented migrant children in federal
custody has
skyrocketed in the last year
, totaling about 13,000. That is a remarkable
increase from May 2017, when the number was only 2,400.

These children either were among the 2,500 forcibly
separated from their parents by the Trump administration’s “zero-tolerance”
or they crossed the border alone. Many are seeking asylum. Normally,
the kids would be held in custody at shelters or foster homes until they can be
placed with a sponsor while awaiting the outcome of their immigration process.


Part of the problem now is that the number of these
sponsors—who usually are family members or friends—is dramatically dropping due
to the threat by immigration authorities of detaining and deporting sponsors
when they come forward to claim the children.

As the Times noted,
in June officials announced that sponsors and other members of their household would have to submit fingerprints
and be subjected to background checks. That information will be shared with
immigration authorities.

According to CNN, federal immigration officials have
arrested dozens of sponsors
already. An Immigration and Customs Enforcement
official told CNN that 70% of these arrests were for immigration violations.
Last week, ICE official Matthew Albence testified to Congress that 80% of
sponsors or adult household members of sponsors are undocumented. In other
words, they have become a huge target for ICE, with undocumented kids as the bait.


“[W]e are continuing to pursue
those individuals,” Albence said.

Meanwhile, sending kids to the desert in the middle of the
night has been a tough process on both the kids and those trying to help them.
Describing the scene at one shelter in the Midwest during such an event, the Times said:

Some staff members cried when they learned of the move, the
shelter worker said, fearing what was in store for the children who had been in
their care. Others tried to protest. But managers explained that tough choices
had to be made to deal with the overflowing population.


Leah Chavla, a refugee advocate and attorney, told the
newspaper: “This cannot be the right solution.”

the entire report

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Mission impossible: Can you regain access after Twitter lockout?

If you rely on Twitter for business or recreation, it’s time to worry. Although the days of frequent service outages have passed, users have a new cause for concern – getting locked out without explanation by Twitter itself.

Unfortunately, when this happens, you have no recourse, and there is no one to call. It’s bad news.

One of the top technology industry analysts in the world, Ray Wang, whom I have known personally for many years, is a victim of this situation. Wang is no newcomer to Twitter: his account has been active since 2008 and has 119,000 followers. He is also a blue-checked user, meaning Twitter has verified his identity as authentic.

Given his credentials, if this can happen to Ray, then you are also at risk.

The facts: Last Friday, Sept 28, the Ray Wang’s twitter account issued an odd tweet, with a link leading to a Bitcoin scam page supposedly run by Elon Musk. The account username was changed to “Elon.” I saw the tweet and it was obvious Ray’s account had been hacked.

The same day, Twitter locked the account, changed the name back to the pre-hacked state, and sent a form letter to Wang requesting verification to restore access. Ray responded quickly, but Twitter sent this note while continuing to deny access:

​Twitter response to request for user verification

Twitter response to request for user verification

Despite numerous emails, Twitter support eventually closed the ticket related to this issue:

​Twitter closes the case and user remains locked out​Twitter closes the case and user remains locked out

Twitter closes the case and user remains locked out

At this writing, after several days, Wang still cannot access his Twitter account.

What it means and what you should do

This problem happened because Wang no longer has access to the original email he used to sign up for Twitter in 2008. Twitter has not created processes to handle this kind of situation, so account access remains denied with no way to recover.

As we all know, Twitter has become a utility on which we rely. As a public company, we expect Twitter to deliver on their brand promise of ubiquitous communications and user-centric policies. They are no longer a tiny startup where this kind of fail is excusable.

The extent to which Twitter’s policies are incomplete and ill-formed is simply extraordinary. Of course, I understand that Twitter needs to ensure security and does not mistakenly verify an impostor, however, Wang made repeated offers to provide iron-clad methods to prove his identity.

I sent the following email to Twitter seeking a comment:

​Request for comment to Twitter​Request for comment to Twitter

Request for comment to Twitter

Unsurprisingly, the company did not respond to my request for comment.

Take these steps immediately, to ensure you are not a victim of Twitter’s policies:

  • Use a strong password and change it regularly
  • Enable two-factor authentication with a current phone number
  • Remove access from other applications
  • Keep your email address up-to-date. However, if your email no longer works, then you may already be out of luck.

Beyond those steps, frankly, there is not much you can do. Hard to believe, isn’t it?

Thumbnail image from Pixabay

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Brain-to-brain network allows three people to share their thoughts

iLexx via Getty Images

There have been experiments in direct brain-to-brain communication before, but that’s now extending to full-fledged networks. Researchers have developed a three-person brain network that lets participants send thoughts to each other — in this case, to play a Tetris-style game. It used familiar technology, but in a much more scalable format.

The network relied on a combination of electroencephalograms to record electrical activity and transcranial magnetic stimulation to send info. Only one person could both send and receive data, but they also couldn’t see the full screen — that was up to two people who could send thoughts to the receiver. Those two would issue commands to rotate a block by focusing their attention on LEDs flashing at different frequencies, modifying their brain signals. The receiver would not only know whether or not to change the block, but could even determine whether or not one of the senders was playing a trick.

This isn’t telepathy by any stretch. It requires external intervention, and can only send one “bit” of data at a time. The technology could scale up to a much larger number of people, though, and it suggests that you could eventually transmit considerably more complex thoughts across groups. That could easily create confusion (not to mention raise serious privacy issues), but it could be useful for both new forms of communication and help scientists learn about the inner workings of the brain.

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