If you were going to kick off a technological revolution, you'd be hard-pressed to do it with more pizazz than Tesla with its electric cars. But oddly enough, what's driving it all--the electric motor--is an ancient technology at this point. It's lost out to the gas engine for over a century, sure, but it's finally begun to take over transportation, thanks to supporting roles from better batteries and fancy sensors. But the electric motor is in the midst of launching a far bigger, far more subtle revolution--not in cars, but robots. Open up a robotic arm and you'll find that its joints are actually electric motors, known as actuators.

Lithium battery safety is an important issue as there are more and more reports of fires and explosions. Fires have been reported in everything from cell phones to airplanes to robots. If you don't know why we need to discuss this, or even if you do know, watch this clip or click here. I am not a fire expert. This post is based on things I have heard and some basic research.

I'm a big fan of Amazon's Echo line of smart speakers when it comes to smart home control, and the second-generation Echo is a big improvement over the first. But the Alexa-powered Fabriq Chorus delivers more bang for the buck and it sounds better, too. Where the Echo requires an AC outlet to operate, the Chorus features a 2200mAh rechargeable battery that Fabriq says can deliver up to 6 hours of performance, so you can take the speaker with you. The Chorus also comes with a contact-based charging cradle, so you don't need to bother with plugging and unplugging a USB cable to run the speaker--or charge its battery. The 6.3-inch tall cylindrical speaker is wrapped in wooly fabric (you can choose from four designs), with a thin LED ring around its base.

Electric vehicles are the main market for Romeo Power Technology, the Vernon-based lithium-ion battery pack startup. But the company is also using its know-how to make portable battery packs for individuals. On Thursday it introduced the Saber, a ruggedized 2.2-pound bar-shaped device the company says can quick-charge a smartphone 10 times -- or, with the right connectors, 10 smartphones at once. It can also recharge tablets, laptops and small drone aircraft as fast as a wall charger, the company said -- it's "like having a wall-socket in your pocket," said Dion Isselhardt, the company's chief product officer. The Saber itself requires two hours of wall time for a refill.

General Electric Co. is working on a way to use artificial intelligence in electricity grids, a technology that it expects will save $200 billion globally by improving efficiency. "We're also putting a lot into the machine learning side, a lot," said Steven Martin, chief digital officer at GE's energy connections business, at an interview at the Bloomberg New Energy Finance summit in London. "We have a lot of people working on this." This is expected to significantly increase the efficiency of the grid and save consumers money. Researchers are looking into how so-called machine learning can be integrated into businesses from healthcare to computing, and now energy.

Tesla is looking into new ways to swap out the battery packs in its electric cars – a move that would slash the amount of time it takes for drivers to get a full charge. The firm recently filed a patent for a battery-swapping system that can lift up a vehicle and change out its battery pack for a new one in just 15 minutes. According to the patent, the rig could even be installed on a trailer with ramps built on either side, allowing cars to drive right in and out. The patent, filed in May, relies on a mechanical lift that can raise the vehicle to a predetermined height. The patent, filed in May, is designed for Model S and Model X vehicles, and relies on a mechanical lift that can raise the vehicle to a predetermined height.

It's been a week since the Apple Watch Series 3 was revealed, and reviews of the wearable device have poured in -- pointing out the good and bad. The Apple Watch Series 3's major boost from previous models is its support for cellular LTE. However, the Wall Street Journal's Joanna Stern said there were issues with connectivity during the week in which she tested out the new models. Stern also said there were problems with Series 3's battery life. "You're lucky if the battery allows you to roam on cellular for longer than half a day--especially if you're making calls. And only a limited number of third-party apps work without the phone close by. Most worryingly, my colleague Geoffrey Fowler and I experienced cellular connectivity issues on three separate pre-production models, in two different states, on two different 4G LTE carriers. On the AT&T -connected models, the cellular connection dropped, calls were often choppy and Siri sometimes failed to connect. On the one that ran on T-Mobile, I experienced several dropped connections."

Libratone's Zipp and Zipp Mini wireless speakers support Wi-Fi as well as Bluetooth, they have touch-sensitive controls, and they're equipped with microphones. Libratone is now leveraging those features to tap Amazon's Alexa Voice Service and transform the speakers into battery-powered Echo clones that sound much better than the originals. This fall, Zipp and Zipp Mini owners will be able to download a free firmware update that activates Alexa. Once that's installed, they'll be able to use voice commands to control their speakers as well as their smart-home devices. They'll also be able to ask Alexa for news, sports, and traffic updates and anything else an Amazon Echo, Echo Dot, or Amazon Tap can do. Unlike Amazon's speakers, they'll be able to deploy the Zipp and Zipp Mini in multiple rooms--just like Sonos speakers.

Amazon's Echo Dot is the most cost-effective way to add voice-activated control to your smart home. There's an Alexa skill for just about every smart-home platform, DIY or custom installed, and second-generation Echo Dot's cost just $50 each. I have six deployed in my own house, connected to a Vivint Smart Home system. The Vaux speaker dock changes that and delivers a bonus: A rechargeable battery that lets you take Alexa all over your house--and out onto the porch, too. The Vaux costs $50, so it and an Echo Dot still cost less than Amazon's own portable Alexa solution, the Amazon Tap. The Vaux's speaker not only sounds better than the Tap, it doesn't force you to press a button to get Alexa's attention like the Tap does.

As technology tries to maintain its dizzying ascent, one dead weight has kept its altitude in check: the battery. Our chips keep getting faster and our data rates keep climbing, but at the end of the day--or worse, by mid-afternoon--those power meters on our screens inevitably turn to red. Every great device, gadget, electric car, and robot would be even greater if batteries didn't suck so badly. Despite a steady flow of rumors that transformative breakthroughs are just around the corner, progress has moved at the pace of a tar flow. Steven Levy is Backchannel's founder and Editor in Chief. Sign up to get Backchannel's weekly newsletter.