charging

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Nine men of various ages and ethnicities stand in a very clean laboratory space. A number of large white cabinets with displays are on the left behind some white boards and there are wireless charging coils on a dark tablecloth in the foreground. In the back of the lab is a white Porsche Taycan.

Polyphase Wireless EV Fast Charging Moves Forward

June 21, 2024 by 85 Comments

While EV charging isn’t that tedious with a cable, for quick trips, being able to just park and have your car automatically charge would be more convenient. Researchers from Oak Ridge National Lab (ORNL) and VW have moved high-speed wireless EV charging one step closer to reality.

We’ve seen fast wireless EV chargers before, but what sets this system apart is the coil size (~0.2 m2 vs 2.0 m2) and the fact it was demonstrated on a functioning EV where previous attempts have been on the bench. According to the researchers, this was the first wireless transfer to a light duty vehicle at 270 kW. Industry standards currently only cover systems up to 20 kW.

The system uses a pair of polyphase electromagnetic coupling coils about 50 cm (19″) wide to transfer the power over a gap of approximately 13 cm (5″). Efficiency is stated at 95%, and that 270 kW would get most EVs capable of those charge rates a 50% bump in charge over ten minutes (assuming you’re in the lower part of your battery capacity where full speeds are available).

We’ve seen some in-road prototypes of wireless charging as well as some other interesting en route chargers like pantographs and slot car roads. We’ve got you covered if you’re wondering what the deal is with all those different plugs that EVs have too.

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Off-Grid EV Charging

August 19, 2023 by 41 Comments

There are plenty of reasons to install solar panels on one’s home. Reducing electric bills, reducing carbon footprint, or simply being in a location without electric service are all fairly common. While some of those might be true for [Dominic], he had another motivating factor. He wanted to install a charger for his electric vehicles but upgrading the electric service at his house would have been prohibitively expensive. So rather than dig up a bunch of his neighbors’ gardens to run a new service wire in he built this off-grid setup instead.

Hooking up solar panels to a battery and charge controller is usually not too hard, but getting enough energy to charge an EV out of a system all at once is more challenging. The system is based on several 550W solar modules which all charge a lithium iron phosphate battery. The battery can output 100 A DC at 48 V which gives more than enough power to charge an EV. However there were some problems getting this much power through an inverter. His first choice let out the magic smoke when it was connected, and it wasn’t until he settled on a Growatt inverter capable of outputting 3.5 kW that the system really started to take shape.

All of this is fairly straightforward, but there’s an extra touch here that makes this project noteworthy. [Dominic] wanted to balance incoming power from the photovoltaic system to the current demands from the EVs to put less strain on the battery. An ESP32 was programmed to only send as much power to the EVs as the solar system is producing at any given time, and also includes some extra logic to make sure the battery doesn’t drain itself from the idle power requirements of the inverter. Right now the system works well but the true test will be when it goes through its first winter. Even though solar panels are more efficient at colder temperatures, if the amount of sunlight or the angle of the panels aren’t ideal there is generally much less production.

Harvesting Rechargeable Batteries From Single-Use Devices

June 7, 2023 by 63 Comments

The price of lithium batteries has plummeted in recent years as various manufacturers scale up production and other construction and process improvements are found. This is a good thing if you’re an EV manufacturer, but can be problematic if you’re managing something like a landfill and find that the price has fallen so low that rechargeable lithium batteries are showing up in the waste stream in single-use devices. Unlike alkaline batteries, these batteries can explode if not handled properly, meaning that steps to make sure they’re disposed of properly are much more important. [Becky] found these batteries in single-use disposable vape pens and so set about putting them to better use rather than simply throwing them away.

While she doesn’t use the devices herself, she was able to source a bunch of used ones locally from various buy-nothing groups. Disassembling the small vape pens is fairly straightforward, but care needed to be taken to avoid contacting some of the chemical residue inside of the devices. After cleaning the batteries, most of the rest of the device is discarded. The batteries are small but capable and made of various lithium chemistries, which means that most need support from a charging circuit before being used in any other projects. Some of the larger units do have charging circuitry, though, but often it’s little more than a few transistors which means that it might be best for peace-of-mind to deploy a trusted charging solution anyway.

While we have seen projects repurposing 18650 cells from various battery packs like power tools and older laptops, it’s not too far of a leap to find out that the same theory can be applied to these smaller cells. The only truly surprising thing is that these batteries are included in single-use devices at all, and perhaps also that there are few or no regulations limiting the sale of devices with lithium batteries that are clearly intended to be thrown away when they really should be getting recycled.

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Wireless Charging On A Massive Scale

March 21, 2023 by 26 Comments

Despite the increasing popularity of various electric vehicles, the limits of battery technology continue to be a bottleneck in their day-to-day use. They don’t behave well in extreme temperatures, they can wear out quickly, and, perhaps most obviously, charging them is often burdensome. Larger batteries take longer to charge, and this can take a lot of time and space, but this research team from Chalmers University are looking to make this process just a little bit easier.

The group has been developing an inductive wireless charging method for large vehicles including cars, trucks, busses, and ferries that can deliver 500 kW across a 15 cm (6 inch) air gap. The system relies on a silicon carbide semiconductor and extremely thin copper wire in order to make all this happen, and eliminates the need for any human involvement in the charging process. This might not be too much of a hassle for plugging in an electric car, but for larger vehicles like busses and ferries traditional charging methods often require a robot arm or human to attach the charging cables.

While this technology won’t decrease the amount of time it takes batteries to charge, it will improve the usability of devices like these. Even for cars, this could mean simply pulling into a parking space and getting the car’s battery topped off automatically. For all the talk about charging times of batteries, there is another problem looming which is that plenty of charging methods are proprietary as well. This charger attempts to develop an open-source standard instead.

Thanks to [Ben] for the tip!

A white longtail cargo bike sits on grass with fenced-in planters behind it. The bike has a basket made of black metal tubes on the front and a passenger compartment behind the rider seat for children made of similar black metal tubes. A white canopy is above the passenger compartment and a solar panel sits atop the canopy.

Solar Powered E-bike Replaces Car Trips

February 7, 2023 by 20 Comments

E-bikes can replace car trips for some people, and adding a solar panel can make the fun last longer. [Luke] did some heavy modifications to his RadWagon to make it better, stronger, and faster than it was before.

The first step was replacing the stock 750 W controller with a 1500 W model to give the motor twice the power. [Luke] plans to replace the motor if it gets fried pushing too much juice, but is planning on just being careful for now. To stop this super-powered ride, he swapped the stock mechanical discs out for a hydraulic set which should be more reliable, especially when loading down this cargo bike.

On top of these performance enhancements, he also added a 50 W solar panel and maximum power point tracking (MPPT) charge controller to give the bike a potential 50% charge every day. Along with the OEM kid carrier and roof, this bike can haul kids and groceries while laughing at any hills that might come its way.

Checkout this other solar e-bike or this one making a trip around the world for more fun in the sun.

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Hackaday Links: January 22, 2023

January 22, 2023 by 48 Comments

The media got their collective knickers in a twist this week with the news that Wyoming is banning the sale of electric vehicles in the state. Headlines like that certainly raise eyebrows, which is the intention, of course, but even a quick glance at the proposed legislation might have revealed that the “ban” was nothing more than a non-binding resolution, making this little more than a political stunt. The bill, which would only “encourage” the phase-out of EV sales in the state by 2035, is essentially meaningless, especially since it died in committee before ever coming close to a vote. But it does present a somewhat lengthy list of the authors’ beefs with EVs, which mainly focus on the importance of the fossil fuel industry in Wyoming. It’s all pretty boneheaded, but then again, outright bans on ICE vehicle sales by some arbitrary and unrealistically soon deadline don’t seem too smart either. Couldn’t people just decide what car works best for them?

Speaking of which, a man in neighboring Colorado might have some buyer’s regret when he learned that it would take five days to fully charge his brand-new electric Hummer at home. Granted, he bought the biggest battery pack possible — 250 kWh — and is using a standard 120-volt wall outlet and the stock Hummer charging dongle, which adds one mile (1.6 km) to the vehicle’s range every hour. The owner doesn’t actually seem all that surprised by the results, nor does he seem particularly upset by it; he appears to know enough about the realities of EVs to recognize the need for a Level 2 charger. That entails extra expense, of course, both to procure the charger and to run the 240-volt circuit needed to power it, not to mention paying for the electricity. It’s a problem that will only get worse as more chargers are added to our creaky grid; we’re not sure what the solution is, but we’re pretty sure it’ll be found closer to the engineering end of the spectrum than the political end.

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Hackaday Links: December 4, 2022

December 4, 2022 by 25 Comments

Well, this is embarrassing! Imagine sending a multibillion-dollar rover to an ancient lakebed on Mars only to discover after a year of poking around at the rocks that it might not actually have been a lake after all. That seems to be the impression of Jezero Crater that planetary scientists are forming after looking at the data coming back from Perseverance since it nailed the landing in what sure as heck looked like a dried-up lake, complete with a river delta system. A closer look at the sediments Perseverance has been sampling reveals a lot of the mineral olivine, which on Earth is rare near the surface because it readily reacts with water. Finding lots of olivine close below the surface of Jezero suggests that it either wasn’t all that watery once upon a time, or that what water was there was basically ice cold. The results are limited to where the rover has visited, of course, and the nice thing about having wheels is that you can go somewhere else. But if you were hoping for clear signs that Jezero was once a lake teeming with life, you might have to keep waiting.

In other space news, we have to admit to taking NASA to task a bit in the podcast a couple of weeks back for not being quite up to SpaceX’s zazzle standards with regard to instrumenting the SLS launch. Yeah, a night launch is spectacular, but not having all those internal cameras like the Falcon has just sort of left us flat. But we should have been more patient, because the images coming back from Artemis 1 are simply spectacular. We had no idea that NASA attached cameras to the solar panels of the Orion spacecraft, which act a little like selfie sticks and allow the spacecraft to be in the foreground with Earth and the Moon in the background. Seeing Earth from lunar distance again for the first time in 50 years has been a real treat, and getting our satellite in the frame at the same time is a huge bonus.

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