Understanding the Electrical Situation

Here's how I determined what I needed: Before I added my passing lamps, my battery charger would show the 'charged up', green light in less than a minute when connected to my battery. When I added my passing lamps, it took several minutes to get the green light, no matter how long or short my ride was. Now that I have upgraded my stator, I am getting the green light even quicker than ever. I have concluded from this that my electrical system was just about maxed out before I upgraded my stator--where output from the charging system was barely equal to the bike’s needs.

The owner’s manual for my bike says that my charging system, via the stator, produces 21 amps, max. So I figure that the stock Road Star electrical components must draw about 17 amps (theoretically), since my passing lamps draw a little over 4 amps***. 21 minus 4 equals 17.

***Calculation: To convert watts to amps, you use: watts divided by volts. My passing lamps are 50 watts for both. Divide this by 12 (volts), equals a little over 4 amps that the passing lamps draw.

My upgraded stator produces 31 amps (max), so I feel I have about 5 or 6 amps of surplus capacity. I know; I know: 31 amps for the new stator minus 21 amps from the stock stator should leave 10 amps of untapped power. But I want to run my electrical demands at less than 85% of my charging capacity so as to keep components from overheating and burning out prematurely. Remember, this is all based on maximum output. I've read of too many stories of owners replacing their speedo or fuel sender unit or other component (multiple times), and I feel it just might be that those sensitive components are heating up because the total electrical draw for their bike is very near the capacity of their charging and regulating system.

Tip: On my bike, I have removed some stock components, but here's the reality: My bike has LED taillight and turn signals. Also I have removed my electric fuel pump. However, the taillight saved me only about 0.5 amps, and the turn signals use a load-equalizer which nullifies any gain from using LEDs. I also figured that any electrical gain from eliminating the fuel pump would be extremely small, given how infrequently it operates.

What's your total?