by tomcam on 4/17/25, 8:46 PM
FWIW I find these batteries and the charger to be exceptional. You can just leave batteries in and it knows when to stop charging. If you get the big charger and put a bunch of batteries in it charges them round-robin style. And the batteries themselves seem to be sturdy, robust, and high capacity. They're also expensive af so you want to wait for a sale if possible. I even spent a ridiculous amount of money on the battery-powered wet/dry vac and haven't regretted it for a moment.
by Liftyee on 4/17/25, 6:12 PM
Always love to see an in-depth reverse engineering write-up. This one's particularly interesting since I'm currently designing a battery pack for my own project.
Interesting to see a microcontroller (and quite a classic one...) as well as an ASIC for battery management. I imagine it's for communication purposes. The battery management chips I've been looking at have built in I2C interfaces to let me avoid firmware.
by noefingway on 4/17/25, 10:46 PM
I have a substantial investment in both Dewalt and Milwaukee tools that I use regularly in my farming operation. I definitely prefer the Milwaukee tools to the Dewalt. I recently bought a 6" Milwaukee chain saw for light duty cutting. I get a lot of cuts before I have to change batteries. Also the torque in the Milwaukee 3/4" impact gun is truly amazing and the battery lasts through a lot of bolt removals.
by bityard on 4/17/25, 8:55 PM
One Christmas, I was given a shiny new 14.4V Craftsman NiCad drill with two batteries. These were not cheap and I was young and broke and very grateful for the thoughtful gift. It worked great and I enjoyed it immensely. For about a year.
After that, neither pack would hold a charge long enough to be useful. Which I thought was pretty disgusting. Come to find out, this was basically the normal standard to which Craftsman had finally sunk. Rather than do the rational thing and throw it out, I held onto it with with a grudge and a goal of actually making it useful again one day.
A few years back, I found a decent deal on brand-new 18650 high-current LiFePo4 batteries from a reputable supplier ($2.50 each, sadly NLA) and bought up a bunch to remake the packs for this drill and a couple others I had laying around for similar reasons. I added an inexpensive but well-made BMS (which I tested thoroughly before implementing) and the voltage was upped to 16V nominal for a little extra kick. Don't ask how I spot-welded the tabs to the batteries.
4.5 years later and these drills are still going strong, I use them at least once a week on both small and large projects. They are not speed demons or torque monsters, but they drill all the holes I ask them to. Would I have been better off economically throwing these ones in the garbage and just buying the cheapest thing from Harbor Freight? Maybe.
But spite, it turns out, is its own reward and I would do it all over again a heartbeat.
by throwaway48476 on 4/17/25, 7:29 PM
The EU is forcing toolmakers to use standard batteries. Hopefully we can get them in the US too.
by glitchc on 4/17/25, 7:21 PM
I'm not sure I follow. Aren't all lithium charging circuits basically the same nowadays, namely an SMC paired with a voltage pump or switching power circuit?
by mrbigbob on 4/18/25, 1:15 PM
Youtube channel Torque Test Channel did a video on various new "tabless" batteries from various tool companies and most do provide more power per amp compared to the older models.
https://www.youtube.com/watch?v=QJuevwLJyMQ
by gcormier on 4/17/25, 7:01 PM
by oakwhiz on 4/18/25, 1:02 AM
I have a big 21 volt power supply hooked up to the empty shell of one of these batteries, with a resistor divider supplying 3.3v to trigger the tools to accept power. It works.
by latchkey on 4/18/25, 4:30 AM
Don't forget that you can buy fairly inexpensive adapters for the batteries. So, you can run your Dewalt on your Milwaukee batteries and not feel vendor locked.
by whalesalad on 4/17/25, 6:20 PM
As a heavy user of Milwaukee gear this is a very pertinent and interesting analysis.
by BonoboIO on 4/18/25, 12:02 AM
One of my Makita 18V 1.5Ah failed a few days ago, I m tempted to by knockoff instead of the brand name.
Am I in danger?
by devwastaken on 4/17/25, 9:21 PM
why cant i use an external DC power supply to replace the one in the chargers? no reason they cant be USB-c given proper supply but there seems to be some kind of special signaling.
by stuckkeys on 4/17/25, 9:54 PM
I appreciate the mild humor injected into various scenes.