Left for the 400 mile ride down US-59 to the Kansas Rally yesterday morning on the 2007 F800S. About 200 miles into the ride the engine doesn’t seem to be idling down after 80 MPH passing, but when I stop for fuel it runs fine. Another 2 hours riding and it’s idling at 4000 RPM, but idle drops down but rough when I reboot the computer by shutting the bike off and restarting it. I’m 280 miles from home but 120 miles from the rally, if I was riding an airhead I would have kept going, heck woulda probably been able to fix it right there. Only 3 pm so I still had time to make it back home, so got onto parallel I-29 to slab it home being the bike doesn’t want to idle. Refueled in Sioux City and the bike runs fine @70-80 MPH, then about 25 miles later the guages go dead but the bike still runs. Not much of anywhere to stop so I keep going, almost made it through Sioux City when the bike completely died and I coasted off I-229 at the “stockyards exit”. Tipped the bike over getting it over a curb and out of the street. Battery completely dead and smells like electrons being liberated. Stripped off enough tupperware to access the battery and found nothing amiss, hooked up my lithium jumper battery and it starts but dies as soon as it’s disconnected. Nothing at this exit but trailer parks and gravel pits, so I put on my helmet, reconnect the jumper battery, start the bike, and it runs long enough to get me backtracked a couple miles to an exit with an Autozone, motels, fast food, etc.. Autozone folks are nice and left me use their voltmeter, voltage is down around 9 volts and won’t restart. Buy an amp and a half charger, the nice Autozone folks let me plug it in there. After two hours charging it starts and I backtrack to get my Dareen jacket, tank bag, and tent that I left at the exit where it first died, but after a mile the lights are dying already and I head back to the motel room I’d gotten and plug in the charger again.
This morning after charging the battery for 10 hours it starts. I fuel the bike and double back to the exit where I’d left my stuff, and all that remains is the tupperware. Bike is now refusing to idle again so I head back to motel for more coffee and call a tow truck. They gouged me nearly $500 for an 80 mile haul, add up the damages and I’m out around $2000 and I haven’t even started to fix the lemon BMW again. This is the second time the F800S has died on the road, a worse record than even my Buell.
That $2000 would have been better spent on a used Airhead!
GearheadGrrrl 
Sorry. The same thing happened to me twice on a 2007 F800S. The stock Exide battery experienced “suddenly death syndrome” in about a year from new, leaving me stranded. Then around 35,000 miles, the stator burnt to a crisp. Got it rewound, and all is ok, but at 53,000 miles, I expect it to go south again soon.
If this happens to you again, I’d suggest getting a new battery. Or two. Much cheaper than a tow and $2k down the drain.
Also, get a $50 Datel volt meter and wire it up. It won’t stop the stator from frying, but will at least give you some warning that there are no more fresh happy new electrons coming from the alternator to your battery.