RC-Monster Forums - View Single Post - How to prevent Sparking when connecting batteries with an MGM controllers

BrianG · 03:49 PM

This type of thing can be done with Deans just as easily (actually, probably easier):

Just hook the mini-deans up first, wait ~10 seconds, then hook up the main leads.

The resistor in the pic above is based on 1,000uF ESC total capacitance and an approximately 10 second charge time. The actual formula for picking the resistor value is:

R = S / 5 / C

R= Resistor in ohms
S= Time in seconds
C= Capacitance in farads

So, if your ESC has three 330uF caps (990uF total) and you want them charged in 5 seconds, the resistor to use would be 1010 ohms, or 1k.

The required resistor power rating can be found by the formula:

P = V^2 / R * 2

P= Power in watts
V= Battery voltage
R= Resistance in ohms

So, for a battery voltage of 22.2v (6s) and a 1k ohm resistor, use a 1W resistor.

	(#7)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	02.18.2008, 03:37 PM This type of thing can be done with Deans just as easily (actually, probably easier): Just hook the mini-deans up first, wait ~10 seconds, then hook up the main leads. The resistor in the pic above is based on 1,000uF ESC total capacitance and an approximately 10 second charge time. The actual formula for picking the resistor value is: R = S / 5 / C R= Resistor in ohms S= Time in seconds C= Capacitance in farads So, if your ESC has three 330uF caps (990uF total) and you want them charged in 5 seconds, the resistor to use would be 1010 ohms, or 1k. The required resistor power rating can be found by the formula: P = V^2 / R * 2 P= Power in watts V= Battery voltage R= Resistance in ohms So, for a battery voltage of 22.2v (6s) and a 1k ohm resistor, use a 1W resistor. Last edited by BrianG; 02.18.2008 at 03:49 PM.