Worx / Yardworks Battery clip by Coil_B

Last crawled date: 2 years, 10 months ago

Fits Yardworks and Worx Batteries.
Needed
two pieces of 0.030 inch (ish) copper 6mm X 30mm
hook up wire
Optional
battery low voltage protection board, like: GM00001029: https://www.ereplacementparts.com/pcb-p-80464.html
For the terminals, I just used some 0.030" thick copper 6mm X 30mm. I drilled a hole into each 16mm (5/8) back from the terminal ends (battery side) and aligned them up with the circular hole in the centre of the slot. That way when they are held in with some sort of adhesive, the adhesive will go through the hole in the copper and lock it a bit more securely and hopefully not move when removing and installing the battery. Your aiming for a 12mm (1/2) terminal stick out.
Note for Battery safety
When using a lithium ion battery like this you must make sure not to overheat the battery by drawing too much current for long periods of time and you must keep the battery voltage from dropping below 15v to avoid long term damage. There is no thermal or minimum voltage protection in the Battery! The tool itself is what shuts the power off when the battery requires it, it does that through software, that is why there is more than two Battery connections on cordless tool Batteries.
To keep the battery from over heating, all you can really do is keep the current low, about 3 amps or less continuous. If you need more than that the Best thing is to open the Battery up and googling the number on the cells to see what the max discharge current is.Mine had Samsung high drain 1NR18650-20R in it (the exact same as Milwaukee uses interestingly enough),with a max drain of 22 Amps, I don't thing I would draw more than 10 amps out of the battery pack personally without knowing what the batteries circuit board is designed to carry.
To Keep the Battery voltage above 15v, a low voltage disconnect board can be used. The GM00001029 is an available low voltage cutoff board Makita uses in their flashlights. Its can handle about 2 amps. To get the boards to handle more current you can swap the big square transistor out to a mosfet like a IRF4905PBF, then your limited by the tracks on the circuit board.

Higher Current Battery Protection Board
If your feeling adventurous I attached the gerber file(circuit board design file) and a BOM (bill of materials) for a battery protection board. Just use a service like JLCPCB, click order now, add the ZIPPED gerber file (Drill Battery Protection Board.zip), select the quantity, colour, leave all other setting at the default value, add to cart and the rest is a normal online order. For a drill battery (5 cell) use a 330 Kohm resistor in the "adj." spot.
The board can handle 10 Amps with a heat shink on the mosfet (limited by track thickness of board), adjust the blue potentiometer so it shuts off at 15 volts. I added a spot for two resistors if you prefer that, they should add up to around 62 Kohms but could vary depending on the tolerance of the components.