Supersized Power Bank Built From An EV Battery

February 3, 2022 by Jenny List 25 Comments

Perhaps one day in the future when our portable electronics are powered by inexhaustible dilithium crystals, we’ll look back fondly on the 2020s when we carried around power banks to revive our flagging tech. Oh how we laughed as we reached for those handy plastic bricks only to find them drained already of juice, we’ll say. [Handy Geng] won’t be joining us though, because he’s made the ultimate power bank, a 27,000 AH leviathan that uses an electric car battery for storage and supplies mains power through a brace of sockets on its end.

The vehicle battery is mounted on a wheeled trolley along with what appears to be either the in-car charging unit or a mains inverter. The whole thing is styled to look like a huge version of a pocket power bank, with a curved sheet metal shell and white hardboard end panels. The demonstration pushes the comedy further, as after charging a huge pile of phones he replenishes an electric scooter before settling sown by a chilly-looking river for a spot of fishing — along with his washing machine, TV, and electric hotpot for a spot of cooking. We appreciate the joke, and as we know him of old we’re looking forward to more.

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USB Power Has Never Been Easier

January 5, 2022 by Brian McEvoy 48 Comments

USB cables inevitably fail and sometimes one end is reincarnated to power our solderless breadboards. Of course, if the cable broke once, it is waiting to crap out again. Too many have flimsy conductors that cannot withstand any torque and buckle when you push them into a socket. [PROSCH] has a superior answer that only takes a couple of minutes to print and up-cycles a pair of wires with DuPont connectors. The metal tips become the leads and the plastic sheathing aligns with the rim.

The model prints with a clear plus sign on the positive terminal, so you don’t have to worry about sending the wrong polarity, and it shouldn’t be difficult to add your own features, like a hoop for pulling it out, or an indicator LED and resistor. We’d like to see one with a tiny fuse holder.

If you want your breadboard to have old-school features, like a base and embedded power supply, we can point you in the right direction. If you are looking to up your prototyping game to make presentation-worthy pieces, we have a host of ideas.

Rugged Solar Generator Packs A Punch

September 7, 2021 by Dave Rowntree 29 Comments

Hackaday Prize 2021 entrant [Philip Ian Haasnoot] has been building a well-polished power bank. But this is no ordinary little power bank the like you would throw in your rucksack for a day out. No, this 2.5 kW luggable power bank is neatly encased in a tough, waterproof Pelican 1550 case, and is suitably decked out with all the power sockets you could possibly need for a long weekend of wilderness camping and photography.

Testing the hand-built 18650 based battery bank — Boy, that’s a lot of tab welding

This box sports USB-C and USB 3.0 connectors for gadget charging, as well as 12 VDC cigarette lighter and XT-60 ports for high-drag devices. Also it provides a pair of 120 VAC sockets via an integrated inverter, which at 1.5 kW could run a small heater if you were really desperate, but more likely useful to keep your laptop going for a while. Now if only you could get Wi-Fi out in the desert!

[Philip] doesn’t actually talk much about the solar panels themselves, but we know the box contains a 600 W MPPT boost converter to take solar power in, and feed the LiPo battery pack in the correct manner.

The battery pack is custom-made from salvaged and tested 18650 cells, as you would expect, which we reckon took an absolute age to make by hand. The whole project is nicely finished, and looks like something we’d be happy to throw in the back of the car before heading out into our local wilderness.

As [Philip] says in the project description, it’s a tough job to carry enough power and keep all his drones, cameras and lighting equipment charged, not mention helping prevent the campsite occupants from freezing overnight during the chilly Arizona nights.

Many power bank designs have graced these fair pages over the years, like this rather polished build, and long may they continue to do so.

USB Power Bank’s Auto-Off Becomes Useful Feature In Garage Door Remote

July 6, 2021 by Donald Papp 10 Comments

For devices that are destined for momentary and infrequent use as well as battery power, some kind of power saving is pretty much a required feature. For example, when [PJ Allen] turned two ESP8266-based NodeMCU development boards into a replacement wireless remote garage door opener, a handy USB power bank ended up serving as a bit of a cheat when migrating the remote away from the workbench. Instead of moving the board from USB to battery power and implementing some kind of sleep mode or auto-off, [PJ Allen] simply plugged in a USB power bank and let it do all the work.

This is how the feature works: some USB power banks turn themselves off unless they detect a meaningful current draw. That means that if the power bank is charging a phone, it stays on, but if it’s only lighting up a few LEDs, it’ll turn itself off. This feature can be a frustrating one, but [PJ Allen] realized that it could actually be useful for a device like his garage door remote. Turning on the power bank delivers 5 V to the NodeMCU board and allows it to work, but after about fifteen seconds, the power bank turns itself off. Sure, strapping a power bank to the remote makes the whole thing bigger than it needs to be, but it’s a pretty clever use of the minimum load as an effortless auto-off feature.

The NodeMCU boards in [PJ Allen]’s DIY remote use ESP-NOW for their wireless communications, a nifty connectionless protocol from Espressif that we’ve seen used in other projects as well, such as this ESP32-based walkie-talkie.

A Lot Of Effort For A Pi Laptop

April 13, 2021 by Bryan Cockfield 7 Comments

Building a Raspberry Pi laptop is not that uncommon. In fact, just a few clicks from any of the major electronics suppliers will have the parts needed for such a project speeding on their way to your house in no time at all. But [joekutz] holds the uncontroversial belief that the value in these parts has somewhat diminishing returns, so he struck out to build his own Pi laptop with a €4 DVD player screen and a whole lot of circuit wizardry to make his parts bin laptop work.

The major hurdle that he needed to overcome was how to power both the display and the Pi with the two small battery banks he had on hand. Getting 5V for the Pi was easy enough, but the display requires 8V so he added one lithium ion battery in series (with its own fuse) in order to reach the required voltage. This does make charging slightly difficult but he also has a unique four-pole break-before-make switch on hand which doesn’t exactly simplify things, but it does make the project function without the risk of short-circuiting any of the batteries he used.

The project also makes use of an interesting custom circuit which provides low voltage protection for that one lonely lithium battery as well. All in all it’s a master course in using some quality circuit-building skills and electrical theory to make do with on-hand parts (and some 3D printing) rather than simply buying one’s way out of a problem. And the end result is something that’s great for anything from watching movies to playing some retro games.

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Custom Powerbank In Compact Form Factor

December 27, 2020 by Danie Conradie 28 Comments

The wide availability and power density of 18650 lithium-ion cells have made them a good option for everything from electric cars to flashlights. [Theo] needed a new power source for his FPV drone goggles, so he designed his own power bank with a very compact charge controller.

While [Theo] could charge the batteries with an RC battery charger, he preferred the convenience of one with a standard 5V micro USB input, and wanted battery level indication to avoid having the FPV goggles die unexpectedly mid-flight. When four 18650 cells are held in a cube arrangement, a 8x8x65 mm gap is formed between the cells. In this space [Theo] was able to fit a custom PCB with a micro USB jack, 1.3 mm power jack, BQ25606 charge controller, TPS61085 boost converter, and ATtiny MCU with LED for battery level feedback. The charge controller also allows 5V devices to be charged via USB, while the boost converter outputs 9V via the 1.3mm jack for [Theo]’s FPV goggles. Everything fits inside a nice compact 3D printed enclosure.

The project was not without hiccups. After ordering and building the PCB he discovered some minor PCB layout mistakes, and realized the boost converted could only output 600mA at 9V, which was not enough for his more power-hungry googles. He plans to fix this in the next version.

We’ve seen custom power banks in quite a few shapes and sizes, including one that runs on power tool batteries (which probably also have 18650s inside) and one that has just about every output you could want, including AC and wireless QI charging.

Heavy Metal Power Bank Uses Tool Batteries

October 10, 2020 by Tom Nardi 17 Comments

At one time or another, most of us have seen a gadget for sale and thought we could build something similar for cheaper. Of course, we’re almost always wrong. Not about being able to build it, mind you. But when you add up the cost of the materials, the tool or two you almost inevitably end up buying, and the time spent chasing perfection, you’re lucky if you haven’t doubled the original price.

We’re not sure how much money [Taylor Hay] ended up saving by building his own portable power bank. But we do know it’s a gorgeous piece of hardware that’s certainly built far better than the average consumer gadget. The CNC-cut aluminum side panels look like something pulled out of a tank, and while we know some might balk at the 3D printed internal frame, we’re confident you could use this thing as an impromptu step stool without a problem.

Inside there’s 150 watt 240 VAC inverter, complete with a temperature-controlled fan to keep it cool under load. There are also four USB ports providing 2.1 A each, a standard 12 VDC accessory port, and a LED display that shows battery voltage and current being drawn. Rather than come up with his own battery pack, [Taylor] used a 3D printed interface that accepts an 18 V Milwaukee cordless tool battery. Naturally, the design could be adapted to take another brand’s cells if you were so inclined.

Around these parts, we know that a good project doesn’t have to be cheaper or even more practical than what’s already on the market. There’s an inherent value in building something exactly the way you want it that you simply can’t put a monetary price on.

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