by DonaldNZ » Tue Apr 16, 2019 5:13 pm
On my alternator I wont be in a hurry to run a new thicker wire between the alternator and battery.
Most automotive alternators are rated at ~2/3 maximum output
manufacturers don't usually spend more than needed as standard equipment on a alternator.
extra batteries & loads have potential to increase the load on the alternator significantly.
the original wire between the alternator and battery acts as a resistor and as such limits the maximum energy drawn from the alternator, so making it thicker will ,make the alternator work harder and hotter and more inclined to let out smoke.
ways to get more grunt from an alternator; make the environment colder, duct cool air to it extract hot air from it , protect it from the heat of the exhaust and turbo, spin it faster.
My wizard air con pump is right beside an un shielded turbo with the alternator just under that.
I'll eventually shield the turbo from the ac pump and hoses,
around 6000 ~9000 rpm alternator rpm is a good place, faster = cooler due to more fan action, faster again = more likely to throw the rotor winding,
the Bosch load handler 200A 12v alternators alternators will handle a bit faster and have a lower cut in speed , so you may find they do make enough grunt at idle for 8 100 w headlights. 3 fans two beer fridges and a disco light for the missus
vacuum pump though
what is my alternator rpm ?
alternator rpm = crankshaft rpm x pulley diameter circumference difference.
so if crank pulley is 3 x alternator diameter then at 2000 rpm alternator will do 6000.
if crankshaft pulley is 280mm and alternator is 80mm at 2000 crankshaft rpm alternator will do 7000rpm
imagine the stress on the alternator and other devices in belt path when changing gears from say 2500 rpm to 800 back to 2000 made worse when heavier rotor higher output alternators high geared are fitted.
So will your belt handle the extra load ?
hence the development of the one way bearing in alternators, helps on the decellerate still got the accelerate stress. some alternator regulators have soft start where they ramp up the load over a minute to max output so it slowly warms up the belt to hot n grippy.
If you want hard out extra batteries and goodies buy a cheep temperature gauge and fit it to the alternator, I'd reduce loads so it never gets hotter than 90 degrees C, cooler equals long life
some regulators sense alternator temperature and reduce output if they exceed a certain temperature.