What does it all use.

[Carsten]

Question for the electrical experts.
I have a 1994 ST1100, equipped with 35 watt HID headlight conversion, cruise control, Oxford heated grips, Garmin zumo 550 GPS and spare 12volt outlet.  I am looking to add some decent LED driving lights.  Do I have the capacity to safely fit them with everything running?  I have the standard 28 amp alternator.
Thanks in advance.

[Brock]

Add up all the watts of your devices, and dived by 12 to give you the nominal current draw.

Your GPS uses next to nothing, the heated grips are hungry, not sure about the normal use of the bike, but you should have enough to power LED lights, depending on their load (usualy around 4amps each)

[tj189]

remember to add what the bike uses without all your extras as well. Your HID conversion headlight for instance, is now using around 5.8 amps (I would call it 6 amps),  adding a set of, lets say 35w LED will also be around 6 amps.  out of your available 28 amp alternator you now have 16 amps left.  Not sure what you plug into the 12v socket, lets suggest it is something that draws 3amps, you now have 13 amps left.  These 13 amps are to cover what the bike needs (excluding the headlights as we covered these at the beginning) and your cruise control, oxford grips, gps. 

I would agree with Brock that you should have enough but try to be on the safe side and check out what the other bits draw and the bike requires.

[Carsten]

Thanks for the quick replies.  Something to work on.

[Biggles]

I'd reckon you're sailing close to the wind when you're riding on a cold night.
The last thing you want is for a blackout as you come into a bend on at night.
You would need to allow for a 19 year old alternator to have lost a bit of its original power.