Guest vr6galaxy Posted February 6, 2006 Report Posted February 6, 2006 My thinking is if an altenator is rated at 150A regaurdless of how fast it spins it will only give 150A? the reason I ask is that on another fourm I visit a member has a Sharan 150A alternator that he's going fit to his VR6 Golf ;) the only difference between the oe Golf alternator and the Sharan one is the size of drive pully, it's larger on the Sharan, so, if he swaps pullys the alternator will rev faster! but will only kick out the 150A as it doesnt know how fast it's spinning and is made to provide 150A at tick over or full throttle! you with me so far? so will haveing it spin up faster damage the charge system or battery? Quote
seatkid Posted February 6, 2006 Report Posted February 6, 2006 Stupid Question?Correct! :P Coming from you I expect better! :o 1. Alternators fitted to VW units have a fixed Voltage regulator - they regulate the output of the alternator to give between approx 14.3-14.5V regardless of load. It varies a little with temperature/current/age/initial build. 2. Batteries, even when flat only take a limited amount of current to reach 14.3V usually 10-20 amps or less. Its a self protecting characteristic of lead acid batteries. A flat battery therefore needs current to be applied for a long time to recharge fully. You cannot charge a lead acid battery quickly without it exploding! 3. Alternators cannot provide maximum rated output until they are spinning at a rated speed. I would guess that your alternator would be able to provide maximum current at 2000 rpm+ (engine speed). At idle the max output may only be 25%. 4. I don't think alternator outputs are output protected - if you overload them for long enough - something will blow - they may have some form of simple thermal protection though ;) 5. Max outputs are short term limits. so will haveing it spin up faster damage the charge system or battery? probably not, but the alternator may not take revs above its maximum design, both mechanically and electrically. Quote
Guest vr6galaxy Posted February 6, 2006 Report Posted February 6, 2006 Told you was a stupid question ;) Quote
Masked Marauder Posted February 6, 2006 Report Posted February 6, 2006 What have you got to lose? Will it not fit with the bigger pully and a longer belt? Quote
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