R1150gs

[ratiron]

More snow (and cold) for the high country of New Mexico. The electrical system on my 2001 R1150GS is stock and I need to know approximate amps or wattage I may have available to supply electric vest(s) and/or jacket liners. Liners draw approx. 77 watts and vests 45 watts. Would like to be able to supply heat to my wife and myself.

Thank you, oh knowledgable ones, or legpullers, whatever.

Ratiron

[Jim Shaw]

The 1150GS has a seven hundred and mumble watt alternator, which is generally fine for a vest, pants, socks, gloves, handgrips, radar detector, GPS, high beam, low beam, recharging the battery after a start, and running the motorcycle. Add a couple of 55 watt (small) PIAAs, and you're still ok. Beware of adding several big 100 watt off road lights, though, and you're ok.

Some estimates:

Motorcycle: 80 watts
Headlight: 55 watts
Hi Beam: 65
vest:45
pants: 75
handgrips: 50
GPS: 5
radar det: 5
Wife's electrics: 120
Tailights, turn signals, etc.: 50
Recharge power to the battery (after start): 220

The thing to watch for - other than the total load - is the alternator belt. A number of Iron Butt Rally riders (who really use the power at night) discovered that the original alternator belt wears quickly when overloaded. BMW has since come out with a better replacement belt.

Recommended service interval on the belt is 30,000 miles, I think. I had mine replaced with the new design, and carry the old one as a spare.

So - what the above says is that with all this stuff, you're probably at the limit. However, as the battery recovers its charge after a start, the wattage consumed for that use fades to near zero. So, in general, if you don't shut down every 25 miles, you should be ok with the above.

If you want 200 watts of PIAAs on the front for night strafing missions, forego some of the other stuff.

BTW, other than the belt, the 1150GS electrical system has a pretty good track record for reliability.

Jim