| Author | Message | ||
     Pso |
I am fairly ingorant regarding electronic things. Is the Voltage regulator temp. sensative. I ask because when we are in triple digit heat index #'s such as today it seems as if when I start out the Voltage is reading about 12.7 at idle, then about 14v at around 3k RPM. After riding for awhile the voltage drops back down to as low as 12.9. I am also wondering if this is a result of the fan also kicking on at the higher temps even when the bike is running in the hot weather. I am concerned because of the problem I had with the plug to the VR from the stator and also the #77 plug, both of which craped out on me, I want to know if the VR or stator is starting to go. Thanks | ||
| Rwven |
What other loads are you running? If you have 2 55W aux. lights the voltage will drop considerably when the fan kicks on. It will cause the ECM to drop out the accessory circuit on mine sometimes. | ||
| Ft_bstrd |
All electronic equipment is heat sensitive. Since the Uly system has a higher stator output, more "excess" power must be shunted to ground. When this excess power is dumped back into the bike it generates heat. Some of this heat is released through the fins of the VR. Some of it is absorbed by the wiring. Some of it is dumped into the primary fluid surrounding the stator. I believe the relationship is that as temperature rises, measured voltage decreases. I believe Nernst Equation? | ||
| Od_cleaver |
Pso, 12.9V seems low. ’07 Buell specs say 13V at 3K RPM with a load of 34 to 38A. Four 55W lights burning are using 17A, half of the current available at 3K RPM. I think that Nernst Equation determines the voltage of a fully charged battery cell. Increasing temperature reduces this voltage. This (I am speculating here on the tie in) is why automotive charging systems are thermally compensated. Automotive systems charge at a higher voltage in cold temps than in hot temps. I would guess that the Buell regulator is also thermally compensated. Electronics do not care about the heat index. That index was just developed to determine how crappy us humans feel with heat and humidity. However, the temperature does affect electronics. Semi-conductors conduct better the hotter it is and conductors (copper wire) the opposite. Some thoughts… Assuming your charging system is 100%, two things that could give you this low reading are: 1. Your voltmeter accuracy is affected by temperature. 2. The point that you measured this voltage is being affected by voltage drops in the wires and connectors. The after market dash gauges give an indication of good or bad. Use a good quality DVM measuring across the battery to be sure. You might find this link useful>> http://electrosport.com/technical-resources/techni cal-articles/how-motorcycle-charging-system-works | ||
| Towpro |
I have the customdynamics LED voltage indicator. Here is the color change voltages Steady Green - Above 12.9 Steady Amber - Above 12.6 Steady Red - Above 12.1 One time I did see it turn steady red at idle when the fan was running once. But I also had bunch of accessories running. I would also check that connector down by the front sprocket (forget the number). If it is starting to melt it could be the problem. | ||
| Pso |
Rwven-I am only running my GPs and Escort Radar Detector which have very low power draws Towpro-Nice to hear about the fan taking so much juice. I was thinking that riding in the real hot my fan would kick on and perhaps that was why the drop in the charging. My Escort radar detector has a numeric voltage reading as does my garmin GPS. the radar detector is very fast refresh and the GPs is more of a 3-5 sec. average. Old-cleaver-thanks for the ref. also I have the radar detector the voltage readout runnig through a power source that is relayed to the battery so it is not direct, the other reading from the GPS I have through the aux plug in the dash, so again more wires. To follow what you and ft bstrd are talking about perhaps I will take bike up to operating temp and connect meter directly to battery. instead of through all the other wiring. | ||
| Ourdee |
Don't forget you are running a headlight. | ||
| Pso |
based upon the above posts I went out to the privacy of my garage and took seat off. Started bike set thottle when hot to a set 13V. Then I awaited the fan. when the fan kicked on th voltage dropped immediatly to 12.4/.5. that would account for some of my volatage drop when very hot out and the fan coming on while riding. It was 100 (without adjustment, thanks Old cleaver) when it dropped from 13.9/14v to 12.9. thus when the fan kicked on probably approx. .5/.6v's. When I reved the engine to 3K after the fan came on the voltage was back up to 13.3 with a little fluctuation upwards. What Ft bstd and Old cleaver talk about regarding drop due to wire temp, and also other heat sources, may account for the remaining .4/.5v's This is good info.Thanks folks |
