3D Printed Battery Pack Keeps Old Drill Spinning

The greatest enemy of proprietary hardware and components is time. Eventually, that little adapter cable or oddball battery pack isn’t going to be available anymore, and you’re stuck with a device that you can’t use. That’s precisely what happened to [Larry G] when the now antiquated 7.2V NiCd batteries used by his cordless drill became too hard to track down. The drill was still in great shape and worked fine, but he couldn’t power the thing. Rather than toss a working tool, he decided to 3D print his own battery pack.

The 3D modeling on the battery pack is impeccable

He could have just swapped new cells into his old pack, but if you’re going to go through all that trouble, why not improve on things a little? Rather than the NiCd batteries used by the original pack, this new pack is designed around readily available AA NiMH batteries. For the light repairs and craft work he usually gets himself into, he figures these batteries should be fine. Plus he already had them on hand, and as we all know, that’s half the battle when putting a project together.

Interestingly, the original battery pack was wired in such a way that it provided two voltages. In older tools such as this one, this would be used for rudimentary speed control. Depending on which speed setting the drill is on, it would either connect to 4 or 6 cells in the original pack. [Larry] didn’t want to get involved with the extra wiring and never used the dual speeds anyway, so his pack only offers the maximum speed setting. Though he does mention that it may be possible to do PWM speed control in the battery itself via a 555 timer if he feels like revisiting the project.

[Larry] tells us the pack itself was rendered completely from scratch, using only the original battery pack and trial-and-error to get the fit perfect. He reused the side-mounted release buttons to save time, but otherwise everything is 3D printed in PETG for its strength and chemical resistance.


This is an entry in Hackaday’s

Repairs You Can Print contest

The twenty best projects will receive $100 in Tindie credit, and for the best projects by a Student or Organization, we’ve got two brand-new Prusa i3 MK3 printers. With a printer like that, you’ll be breaking stuff around the house just to have an excuse to make replacement parts.

Battery Basics – Choosing a Battery for Your Project

If choosing a rechargeable battery for your project intimidates you, [Afroman] has prepared a primer video that should put you at ease. In this tutorial for battery basics he not only walks you through a choice of 5 rechargeable chemistries and their respective tradeoffs, but gives a procedure that will allow you to navigate through the specs of real-world batteries for sale – something that can be the most intimidating part of the process.

You cannot learn everything about batteries in 9 minutes, but watching this should get you from zero to the important 80% of the way there. Even if your project does not give you the specs you need to begin buying, [Afroman] tells you what to measure and how to shop for it. In particular, the information he gives is framed in the context you care about, hopefully ensuring you are not waylaid by all the details that were safe to ignore. If this is not enough, [Afroman]’s prequel video on battery terminology has more detail.

Much like your high school English teacher told you, you need to know the rules before you can choose to break them. Many of battery absolute Dos or Don’ts are written for the manufacturer, who provides for the consumer, not the hacker. Hackaday has published hundreds of battery articles over the years; search our archives when you are ready for more.

Continue reading “Battery Basics – Choosing a Battery for Your Project”

Fail of the Week: Commute-Shortening Electric Scooter

fotw-electric-scooter

Please don’t judge [Alan] on his choice of vests. This project is from 1999 when it was common to see people rockin’ these threads. Anyone who has ever spent time on the University of Minnesota campus in Minneapolis, Minnesota will know that parking is at a premium. [Alan] had a 12-15 minute walk from his parking garage to his office and was considering a cheaper parking location that would balloon that to 20-25 minutes. But engineers don’t see problems, they see project ideas. He started work on a tiny electric scooter that could slim down his commute. Obviously he did find some success, but it was interspersed with failures that make his scooter the Fail of the Week.

Continue reading “Fail of the Week: Commute-Shortening Electric Scooter”

Revive your tired Dremel battery pack

It turns out there’s nothing more than six Nickel Cadmium AA rechargeable batteries inside of that cordless Dremel battery pack. Yep, standard rechargeable AA’s that you can buy most anywhere, and now you can revive that aging battery pack by following [Stuuf’s] guide. Since you’re already at it, a few more bucks will yield a real upgrade by using the superior Nickel Metal Hydride batteries which should yield around three times as much use between charging. We totally understand having a battery pack, since the shape of the case is part of the handheld tool, and it should be easy to interchange the battery as one unit. We just wish that the battery pack had been designed to have the AA cells swapped out by the user once they had reached the end of the line.

Do you have other cordless tools in need of a pick-me-up? Check out this Makita battery pack repair hack for a point in the right direction.

[Thanks Bluewraith]

Zap new life into Ni-Cads

nicad_zap

Apparently you can revive dead Ni-Cad batteries by zapping them with high voltage. Some people have used welders in the past, but many of us just don’t have access to one. This project shows you how to hack a disposable camera into a battery revival device. This could be very cost effective. A single regular AA battery could revive many Ni-Cads. Remember, this doesn’t charge them, just makes them able to be charged again.