I'd like to be able to run heated grips, gloves and a jacket.  Are there availab
Thanks for any help!
Firstly, I live in a country that has no requirements for heated riding gear. When I first bought it my R100 had heated grips but they were never used and were eventually replaced with something else.
That said, I do know a bit about the electrical capabilities of the BMW airhead.
You have 280 watts maximum output at around 3,000 rpm, at lower revs you do not get anything like 280 watts. Which is why simply riding your BMW to and from work in heavy traffic will result in a flat battery.
Saving power.
Conversion to LED lighting for headlight, running lights (parking lights to more recently emancipated former British colonies) tail light and brake light will save you a little of your precious watts, the precise amount depends on what you have currently fitted and what you replace them with.
Making more power
Fit an "authorities" (as in police or military) regulator - this will increase the voltage produced by the alternator slightly, at the risk of slowly boiling your battery to death when you do not have sufficient electrical load turned on to reduce the voltage to what it should be (supposed ideal 13.8 volts, "authorities" regulator 14.2 volts)
Fit replacement high efficiency diode board - frankly, for the costs involved I don't think this is worthwhile unless you also fit a higher output alternator.
Fit higher output alternator and diode board - frankly I think that the net benefit over cost equation on this simply isn't there, but there is a thriving industry in making "better" alternators for airheads. Be Aware that many of the manufacturers of such devices quote their PEAK and not the CONTINUOUS output. The 500watt "high power" alternator frequently becomes a 240~250 watt (yes less than stock) alternator once the diodes heat up. There is quality gear out there, but it costs.
Fit a second bigger alternator. These are generally "home made" that is to say I have never seen anyone advertising a kit. The home brew specials I have seen very from being brilliantly executed to bloody awful - essentially you are trying to do this:-
The principle cause of crippling of the stock alternator is that it runs at crankshaft speed, so the first step is to remove the stock alternator and graft a pulley onto the end of the crank where it used to be - the best executed of these that I have seen sue a modified VW beetle engine pulley as these have a very clever way of adjusting tension by varying the distance between the plate halves of the pulley. Then you grab the alternator of your choice - a nice 100amp single wire Nippondenso type would seem a smart choices as it mounts internal regulation and only requires a connection (via a heavy duty relay) to the battery to do its thing.
Next you need a bracket to mount the alternator to the side of the engine block and lastly you need to machine the front engine cover(s) to allow the passage of the drive belt. This kind of conversion can work very well indeed, in fact I once considered doing it to my R100, but at the end of the day they are ugly and you get to be your own research and development engineer and 1,000 miles from home in pissing down rain is not the time to discover you miscalculated
Alternative suggestion.
Power your heated gloves and jacket with a LiPo battery pack and take the battery with you when you get to where you are going and recharge it from mains power.
Further alternative suggestion, fit ammeter to your bike and power your heated gear via a single or multiple power socket with switches and vary your electrical load according to what the alternator can put out (which means you get to curse me while you slowly freeze in stop/start traffic).
This year was an abnormal winter for us, it briefly got down to 11 degrees (Celcius) for a couple of nights usually winters seldom go much below 15 and then only for a couple of days. I love North Queensland Australia.
