Skil 20v batteries D terminal?

Hi! I had some luck and won some Skil tools and batteries. Now when I have several good batteries I would also like to use them for a new small ev project too power a RC-motor. I plan to 3d print a holder and will there have +/- terminals that slides into those slots in the battery. Now when I messured the battery with a multimeter, I saw 19volts something for less than a second, then it goes away.. since there is a terminal in the middle named ”D” I assume that need to connect to something in a tool to activate the battery? When I compare to the old Makita to the left that have more terminals there I have a stabile voltage between plus and minus. Also on Ryobi One battery I have 18v between plus and minus, those also have a third named ”T”, probably tempsensor, seem to work without. I really want to use my new skil batteries becase they package better in a holder for my application. Any tips How I should fool the ”D”?

If it is to any help in guess work the middle one goes to the yellow here in the charger when I took a sneak peek.

By the way this is the mini project I hope they can supply power to. A large/small drone motor in a gearbox driving the discbrake similar to Bimotal if you have seen that

….A large/small drone motor in a gearbox driving the discbrake ……

Click to expand...

If that really is a motor from a drone, it will probably have a high Kv (high rpm/volt). .and hence need a high reduction ratio to drive an Ebike.
You may want to consider a lower rpm motor to make gearing easier and less lossy.

No maybe not, some universal from amazon for Electric skateboards it says, the gearing will be good

Rickard m said:

Hi! I had some luck and won some Skil tools and batteries.
<snip>
Now when I messured the battery with a multimeter, I saw 19volts something for less than a second, then it goes away.. since there is a terminal in the middle named ”D” I assume that need to connect to something in a tool to activate the battery?

Click to expand...

The wire in the charger is marked as "Data", which implies that there is communication (perhaps a 1-wire type interface, which could be one-way or two-way) between battery and charger/tool.

This may not be bypassable without opening the pack and wiring around the internal BMS (which removes whatever protection it might offer), but you could try "sniffing" the data line with an MCU (arduino nano, etc) when you connect it to a tool. Then "play back" that data when trying to use the battery for some other purpose.