https://www.protoolreviews.com/news/power-tool-manufacturers-who-owns-them/43632/

it is surprising what power tool connections there are

What company makes Bauer tools sold by Harbor Freight?
The tools are made by various OEMs including
Stanley Black & Decker,
Western Forge and
Apex Tool Group.

This website says that
Ryobi +One 18V Lithium Ion battery packs 130501002
have Sanyo made Lithium 18650 size cells inside.

https://www.ifixit.com/Guide/Cell+Re-balance+of+Ryobi+One++18V+Li-ion+Battery+(130501002)/13286

Can anyone confirm that Ryobi uses the Sanyo made Li cells?

Panasonic bought Sanyo a few years ago,
sold the Japanese Eneloop NiMH battery factories to Fujitsu,
and built new factories for battery production in China.

Milwaukee M12 uses the more expensive Samsung Korean made Li 18650 size cells,
and I assume the Milwaukee M18 uses Samsung too.

Since Techtronix owns
Ryobi, Milwaukee and Rigid (Orange body color)
I wonder what Li ion cells are inside Rigid battery packs?

Dewalt to Ryobi DIY adapter

https://hackaday.com/2018/02/20/cross-brand-adapter-makes-for-blended-battery-family/

video on correcting a Li Ryobi battery pack where a few cells dropped below the protection voltage

https://www.youtube.com/watch?v=p13iznXQNDg

Milwaukee M18 for me

I'm all in on Milwaukee M12 and M18 tools. My experience the batteries last a very long time.

December 2019 I spent a bunch for new Milwaukee tools. One is a 1/2 inch M18 drill driver. It is an utter POS! I have barely used it. Its in repair (dropped off today) again for the same issue - clutch does not work. Second time - its an intermittent problem this time, maybe 20% of the time. In their infinite wisdom, they went to electronic clutch. It is garbage. Repair shop said it was the third one this week for the same problem.

My newer Milwaukee M12 drill driver and my old Milwaukee 14.4 drill driver are great, but this M18 is not...............

I have a mix of Milwaukee M12 and M18, all Fuel tools. The impact impressed me so much I bought more tools. The grinder/die grinder go through batteries pretty fast. The 3/8 ratchet isn't super torquey. I have a Dewalt 1/2" impact and other assorted tools at work, and none of them seem to do as well as the Milwaukee tools at home. Possibly apples to oranges, but I like the red stuff better.