This is a very simple device. Essentially, it's a 100-ohm resistor with a 2-mm bullet connector. If you have a 12-S setup, you probably already know how much it sparks when you connect the battery (it's over 50 volts, so no surprise). To set this up, you can cut the positive lead coming out of the 2x6S batteries, and insert a large bullet connector (4 or 5 mm). This device connects in parallel with the big connector. To use it, connect the small bullet connector on this device first, which allows the large capacitors on your ESC to charge up slowly since the current is limited by the 100-ohm resistor. Then, when you connect the big bullet connector there should be no spark. Just be careful to make sure this doesn't confuse your ESC -- for example, a Castle ESC may auto-detect the wrong voltage battery setup because of the resistor.
- Daniel Herron, Port Washington, NY