The first anti-spark switch to utilise an advanced resistor pre-charge system!

Motor controllers usually have large capacitors, and when they initially charge up after being connected to power they can draw insane amounts of current, as much as 3000A for a fraction of a second, which is all that is needed to cause damage to mosfets every time you turn them on. This damage accumulates over time and eventually will lead to failure if no pre-charge system is implemented.

However unlike other anti-spark switches on the market which claim to have a pre-charge system, ours does not work by slowly turning on the mosfets (effectively using them as a resistor to reduce current draw) as this also leads to premature failure by operating the mosfet outside its safe limits (we learned this the hard way with our version 1 design based off the Vedder anti-spark switch).

The Radium design utilises an advanced micro-controller with a two-stage turn on sequence. First a series of high power resistors are enabled which feed power to the motor controller until the capacitors are almost fully charged. Then a powerful gate driver fires up the 6 high power mosfets in a matter of microseconds, allowing the full current to flow to the motor controller. This ensures the mosfets never operate beyond their capability and as a result will last a very long time.

Since there is already a micro-controller for the pre-charge system, we decided to make use of its extra processing power and added an idle shutoff feature as well. This means after 30 minutes of inactivity your board will turn itself off to save power, ensuring the battery can't be over discharged by accidentally leaving/turning it on. The micro-controller also enables the use of a momentary button instead of a latching button so that it can't un-latch itself mid-ride from vibration.

Limited prototypes for beta testing will be available soon.

Features:

• Advanced pre-charge system - ensures reliability
• Auto-shutoff after 30min of inactivity - protects your expensive battery
• Low profile momentary push button with red LED
• High current, high voltage
• Low idle drain current

Specs:

• Voltage: 10-16S (only 12S has been tested under load)
• Max peak current: 540A
• Max continuous current: 100A
• Size with case: 55 x 40 x 15.5 mm
• Size without case: 50 x 35 x 12 mm
• Hole diameter for button: 12mm
• Includes: Anti-Spark switch PCB, 3D printed Case, Momentary button & JST connector

For electric skateboards and longboards, esk8 and eskate DIY.