I wish to add 2 running lights to the Hondasauras. It is a 1971 Honda CB 750 4. It currently has a head light built into the windjammer faring. turn signals front and back and a second tail light mounted to the top and back of the side box fender (also the turn light is there) I don't know the amp putout of my alternator. So do you think 2- 35W H3 driving lights will be okay or should I try to find 2 led lights as I have been told they draw about 1/3 the amps. Sugestions based on your experience and knowledge would be appreciated. Jim in Denver.
Two 35 watt H3's would draw 70 watts. Using 13 VDC as a running voltage, that would be approximately another 5.4 amps draw. Without knowing the total output of your Honda system, it's difficult to say whether this would overload it.
LED's would use much less current. The typical LED uses only 30 milliamps of current. Even ten of them would only be around 300 ma (1/3 amp)
There are some multi-led array lights that are really quite bright. Regardless of which type you use, I would recommend using a relay to control the power through a small switch to ground the relay coil.
Happy Trails!
Thanks for the info. The shop where I bought the Hondasauras told me the alternator is about 300 Watts or 300 -:- by 12 = 25 amps. He estimated my wattage at present is 180 W so I am using
15 amps. 2 35 W (70-:- 12 would be about 5.9 amps so I should be okay). I will see if I can locate some LED as they draw much less. Jim
On my V Strom I added a voltmeter so I could monitor the situation. I have several add-ons, plus heated grips, and if all are on it will overload.
With the Strom, the issue is particularly prevalent when in the city with low rpm's (e.g. idle). The alternator puts out quite a bit less current then.
Originally written by gregbenner on 5/2/2007 6:53 AM
On my V Strom I added a voltmeter so I could monitor the situation. I have several add-ons, plus heated grips, and if all are on it will overload.
With the Strom, the issue is particularly prevalent when in the city with low rpm's (e.g. idle). The alternator puts out quite a bit less current then.
A voltmeter is a very good addition to your instruments. Low voltage will show weaknesses or failures in a charging system much quicker than an ammeter. My present HD has a voltmeter but I've added them on any bike that didn't have one in the past.
the charging system on our old SOHC Hondas is fairly weak. I think you will be asking for trouble to put that kind of additional load on it.
Do you still have the stock beeper for turn signal notification. You likely notice it won't even beep when idling. Just not enough juice.
This is a common known short coming of our old bikes so I'd recommend against it. I'm not sure if a solid state regulator/rectifier would help or not.
