Voltage drop when fan turns on

Rhythm

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Hey Guys,


Having an issue with my 2003 (stock motor) voltage dropping to 12.5v when my fan turns on . Only upgrades done were a Ricks motorsport Hot shot stator and rectifier, rebuilt starter motor and 1 gauge wiring from the starter. After I smoked the rectifier by applying 40 amps I decided to upgrade my charging system using Ricks Motorsport Hot shot Stator and Rectifier.

The stator and rectifier checked out fine using Ricks youtube stator and rectifier trouble shooting tutorial. The battery voltage (new battery plus 175 amp batt) measured 13.8 to 13.5 when at idle and 14.7 cranked @ 5000rpm. However, the voltage drops to 12.8 to 12.5 when the cooling fan turns on. When the cooling fan turns off the voltage climbs back to 13.2 to 13.5 before the fans turn back on dropping the voltage. Cooling system seems to be working correctly, fan kicks in when temp gauge hits half way mark. From my observation it appears this cheap #%$ Battery Plus Battery is part of the problem. For example, while charging on a tender the multi meter displayed 14.2v and when disconnected displayed 13.8v within a hour it dropped to 12.98.



This can create a future oroblem when riding in slow stand still tracking and need to cut the bike off. Also, during my test the headlight (all accesorries) were turned off.


Has anyone experienced anything similar with voltage dropping when the cooling fan turns on.





Rhythm
 
Long time no see friend. Is the 175 CCA battery the correct battery ? just put a 240 CCA in the Gen II that's why I ask. You can always get the battery load tested. Other than you observing the battery dropping when the fan kicks in, is there a problem. This might be normal :dunno:
 
Hey Rob good to see you postn up. The battery plus batt was posted for my bike. The only problem I can really say that I have at the moment is that it take the bike 1 to 2 seconds longer to start and that it takes my tender 30 to 50 min to fully charge after a ride verse 10 to 15 from what I can recall. Busa has been sitting while I have been communting to work on my 500 ninja and playing with my Fj Cruiser and DR650se on the back roads and trails.
 
Busa Makeover.

busa.jpg


busa 2.jpg
 
Looks good brother. Load test that battery, you might have a bad or weak cell.
 
I took the battery plus batt back and got what I really wanted an EarthX battery. I can swap it with my DR650se.
 
Battery will be delivered thur or fri. Johnny Cheese said it sounds normal.
 
Sound normal, it has a good size motor as well as the size of the blade to turn. I know the dual set ups that i make drop to about 12.4ish but come right back up!
Battery will be delivered thur or fri. Johnny Cheese said it sounds normal.
 
Hey Big D, all is well, even when its bad. Do you have any experience with EarthX .batteries?
 
Update! It was the crappy azz battery. New battery (EarthX) , straigth from the box was reading 13.2 at idle and to 13.6with seconds. With cooling fan running voltage dropped to 13.4 (steady), fan off it climb right back to 13.62v in three second. I think if I run it she will give a higher voltage output readiing. I will post the results when I have more time to play with the Busa.

I'm happy!!!
 
Update. Busa idles @14.88v, @ 5k 14.93v. When cooling fan kicked on she dropped to 14.87,14.86volts. After a hour cool down the voltage reading was @ 13.5v
 
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