I've considered whether there might be a market for a battery box that takes user-supplied 18650 cells and adapters to allow its use with various brand power tools.

This would be technically easy, but I'm not sure how successful it would be as a business. Milwaukee also has a habit of suing people using patents that seemed obvious/nonsensical when I tried reading them (http://www.toolsofthetrade.net/power-tools/cordless-tools/mi...).

I'd love that idea too. Tho the particular case you linked looks ridiculous. I'd be more worried about making it compatible with any tool though. The old cartridge video game consoles prevented unauthorized (not pirate) games by patenting the connectors so you couldn't make something that physically plugged in properly. Now there's apparently DRM on batteries! Good luck copying some cryptographic handshake.

Maybe your business would use 2nd hand parts to circumvent patents and crypto. Build some Frankenstein adapter/battery with removable cells.

Patenting the connectors also seems like an abuse the patent system should prevent (there's not actually an invention there). As for DRM, I think we, the tech community should be pushing legislators a lot harder to roll back anticircumvention provisions.

Yea, anti-circumvention law violates the idea that consenting adults should be allowed to do whatever they want in the privacy of their own home. I wonder what will happen to patents if 3D printers become more versatile and as common as 2D printers so common people can download items from online? The download surely won't be patent protected, and the end user might be able to legally print it under the "experimental use" exception.

I disagree. DeWalt has altered their battery type often and have a few different types. Makita seems to only have 2 types of fittings in the last 10ish years and the 2 4amp packs I bought together for $100 are excellent. There is vendor lock in certainly because once you own a large amount of batteries you can simply buy tools individually.

Makita makes nice tools, ive found

Personally, I've found makita to be one of the worst. Their batteries all have a unique ID chip which communicates with the charger. If it fails to charge it more than 3 times, it permanently disables the battery. So it's not at all friendly for someone wanting to replace cells themselves.

I wouldn't trust them for contractor/professional work, but IMO ryobi has done the best job. They've never changed their connector, so a 10 year old drill that came with nicad batteries can still be used with a brand new lithium cell. This is great for a homeowner, you don't have to buy all new tools when Dewalt changes their battery design after 5 years.

How do Makita batteries stack up against other manufacturers? Mostly I've bought into the Milwaukee 18 volt system (M18 Fuel)- I can run a drill or impact driver for days on one charge. Conversely, I've got a cheap Ryobi set that drains almost instantly.

Really depends on the tool and your use. My experience with the 18V impact driver is that it needs a top off every few hours, but that's a good time to take a break anyhow. However the Sawzall and chop saw will chew through the biggest batteries in minutes. Fortunately they charge quickly though they are rather expensive. I think they are on par with the Dewalt stuff though I like the Makita tools a bit more. I guess if my jobs were any bigger I'd be using pneumatic tools so I can deal with recharging between tasks.

I've been in plenty of job sites with limited power and heat, and a fresh cup of coffee would be much appreciated. Sometimes you can't make it down to the lunch truck!

DeWalt has really gone down hill. I recently switched to Milwaukee. I’m not a contractor but a have lots of friends who are, and they are almost all on Milwaukee these days.

Following from the sidelines I feel like there are similar comments made about all brands, both the "X has gone down hill" and "all my contractor friends use Y". I wouldn't put too much weight on such anecdotes.

I know this is anecdotal, but I would agree. I used to work in an auto shop, and we had lots od Dewalt drills & impact drivers. The older ones were typically fine after falling off a lift onto a concrete floor, but out of the new tools 2 drills and 1 impact driver were junk after the first fall. We just ended up buying adapters to use the new batteries with the old tools.

They're all 18650 cells at heart. Your Milwaukee Fuel drill and impact have brushless motors, probably with higher capacity batteries (measured in Amp-hours) than the Ryobi set, which have brushed motors and probably 1.5-2 Amp-hour batteries. There are plenty of power tool review blogs that do tests to see how many fasteners/board feet/etc different brands do with the same capacity battery packs.

FWIW, Milwaukee and Ryobi are owned by the same parent company, Techtronic Industries

I would be really surprised if there were any significant difference between the actual batteries between manufacturers. There isn't that much variation you can do with lithium cells. Biggest thing that comes to mind are the high/low level cutoffs, or how deep the protection circuitry allows charging/discharging. And that is fairly straightforward trade-off between how long the battery lasts on one charge vs how many charge-cycles it can take.

Sony Memory Stick sucked a lot more than this, they forgot to allow for larger capacities so they were obsolete in no time