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300A 20-85V Anti-spark switch

1. Specifications:

Brand Maytech Model Number MTS2009AS
Application Electric Skateboard, Efoil, surfboard, boat, motorcycle, etc Connector Ring Terminal
Max Current 300A Voltage range 20-85V
Max voltage 85V (20S lipo) Color Black
Switch Type Use NMOS to realize switching on/off Power positive Size about 97x56x25mm
Features Switch comes with LED light indicator;
Shutdown current less than 1uA;
Suitable for load: three phase motor speed controller;
Boot soft start; Automatic short circuit protection when boot;
Over temperature protection (The switch Mosfet PCB exceeds the rated value of 110℃ for more than 1s), which is equivalent to overload protection;
Automatic short circuit protection when work.

2. Wiring:

Check video of how to crimp the ring terminal to cable:

3. LED indicator:

LED Idicator on , Normal working condition;

LED I ndicator slow flashing , Startup fail. Possible reasons: “voltage lower than 19V, the load is short-circuited, the load capacitor is too large, the load type is incorrect, the load is short-circuited during use”.

LED I ndicator quick flashing , Over temperature protection (Mosfet PCB temperature is over 110℃ for more than 1s to start the protection). Please turn off the switch and restart when temperature is lower than 110℃.

I tested this anti-spark switch some time ago. Of course, its basic function is to connect a comfortable and non-sparking battery pack to the motor controller. It´s a “breakthrough” switch, so far nothing like this could be obtained commercially, especially for a current load at the peak of 300A and a voltage of 85V (practically usable for battery packs up to 20S).
I want to point out one problem, dominant for battery packs from 12S and up.
When connecting the battery pack, there is a small spark, which this circuit should´t do. The problem is caused by an internal BEC circuit (DC-DC converter) and its input filter capacitor with a capacity of 100u.
With a 14-20S battery and its frequent disconnection and connection, the connectors will gradually get burned.
This problem can be suppressed e.g. by replacing the filter capacitor in the switch with a value of 47u / 100V.