(Comments from Blogger)
2018-09-04 by Anonymous
The 19.2V craftsman drill is awesome I found one in the trash and converted it to 18V lithium (no BMS). it runs great very powerful drill.
Black & Decker 20VMAX (18V) battery power mount by dyslexicEnginer - Thingiverse
I read all your posts, but battery tear-downs are my jam keep em coming!
2018-09-04 by Russell Graves
Very nice! I tend to do battery teardowns as I have packs show up or I find them. They’re fun, but a bit less technically demanding than the stuff I enjoy doing. However, I don’t always have time for the more technical stuff…
2018-09-10 by Unknown
I wouldn’t call that PCB a battery management system, it’s likely just a safety circuit. There are two MOSFETs ganged together because each has a body diode that will conduct in one direction when off. When you put two together you can stop the current in and out. They are big to get the heat out with cheap FETs. An example of a minimal safety IC is https://www.ablic.com/en/doc/datasheet/battery_protection/S8254A_E.pdf.
2018-09-11 by Unknown
both battery was build by same company.
2018-09-17 by Richard
I’m still fully invested in the C3 set. I have 3 of these 19.2v lithium packs, as my 2 NiCD packs wore out. They’re still going fairly strong since I bought most of them between 2012-2013.
2018-11-10 by Unknown
I bought a general (not genuine) 6A/h pack for a M12 Milwaukee tool, and it didn’t contain any circuit. Just a bare pcb with thermistor. It’s normal, because Milwaukee has balancing inside the wall charger. And as for protection… let’s hope it won’t fry ) No fuses inside. And cells were only half of rated capacity, but ok, I bought it cheap.
2018-11-10 by Unknown
Oh, forgot to mention what I wanted to say on subject: over-engineering! )
I’m sure this scheme leaks some current, and you can’t turn it off.
2019-02-26 by avh
Thanks for this teardown of a C3 battery that educates us about the role of a battery management system!
I probably like many C3 tool owners are planning for the future. The C3 tools were made by Ryobi to Sears specifications but are mostly the same as Ryobi. They are fine tools I want to keep. Unfortunately Sears specified a different battery stalk so Ryobi batteries aren’t interchangeable. Craftsman was purchased by Stanley and C3 batteries are not on the new Craftsman site. Sears while it remains open is still selling the batteries. And there are third parties which I hesitate to go with.
So as far as the way to go I’ve found:
Thinginverse Ryobi to C3 adapter: Ryobi battery to Craftsman/Sears cordless tool by Kingmiwok - Thingiverse. Keeps a BMS because Ryobi batteries also have it built-in.
Build an adapter for 20v max: How to use DeWalt Batteries on Ryobi Tools for $30 | Building a DeWalt to Ryobi Adapter - 42Fab #16 - YouTube. This one is for Ryobi but same principles apply for C3. Keeps a BMS because it’s built into the Dewalt 20v max adapter.
Purchase adapter made by LaiPuDuo: google DM18GL (Milwaukee batteries), BPS18GL (Dewalt batteries). These are also on eBay. I don’t know if they have a BMS that’s capable of disconnecting the battery from the tool however. Someone would need to do a teardown.