OK, I know that I'm crazy and will probably fry the Alternator, but I'm intent on wiring 4 x 155w rally lights. They're already fitted



I need some electrical wizardry to shed some light (pun not intended) on such things as fuse size. The lamps will be powered directly from the battery and triggered from my side lights. I would like to run them on two circuits to give me the option of completely blinding or only partly blinding anything in my path.

ANYONE BRAVE ENOUGH TO HELP ????

Paul

 

620 watts of light at 12 volts is roughly 52 amps. This is about half of the stock alternator's capacity of 105 amps. If you plan on running all those lights while having the rest of the stock lighting on, the a/c running, the rear defrost on as well as the inevitable draw of the electric power steering pump (which itself draws more than 50 amps in surges and when the steering is turned against the stops), your alternator will protest, and will not have a long life. Now, if the lighting loads alone (your aforementioned 620W, the stock high and low beam (or low and fog light) load of 220W, tail/running lamp load of roughly 30w) add up to ~820 watts at full glare. That's 72.5 amps. With luck, and light (no pun intended) loading from the rest of the electrical system, you can squeak by. At idle, your battery will be taking up for the slack the alternator cannot make up for. I know of no drop-in replacements made for the MINI alt yet. If you dont plan continuous usage of the lights, you can get away for the short periods of extreme current draw. If you plan on running a rally with the lights on for long periods, you might want to carry a spare alternator just in case. The stock units can take a fair amount of overloading, but doing so for long periods of time goes beyond the duty cycle the thing is designed for.