Electronics » Jump Start

Foolishly, I left my helmet bluetooth on charge for a number of days, and it drained the RS's battery to the point it wouldn't crank.

I tried jumping it from my car's battery, and it cranked once and stpped. I also tried a spare 12 v motorcycle battery that I keep on charge with the same result.

Positive was connected to the jump start terminal. Negative to the frame and the the negative terminal. Same result in all cases.

Has anyone actually jump started the RS?

I put the bike on a charger and the next day all was well.

I am on my third boxer (R1200ST - R1200RS - R1250RS) None of them have I been able to start by rolling in 3-4 gear and release the clutch. Same result always, rear wheel stands completely still. Never tried with auxiliary power however.

My R1100 S would bump start in 3rd (or maybe 4th). I know I needed a good long slope.

As it happens, my drive way is steep but it is "touch and go" on length.

The RS seems to have higher compression coupled with the decompression mechanism that means a bump start, especially on a cold motor, is unlikely.

My son's cafè racer Nuda 900 R (based on the F850) is always an attempt to bump start on the drive way as he prefers that to the electric start, but about 1/3rd of the time it doesn't fire up.

Bump starting on the 1 litre plus twins may be part of history.

You need one of those lithium battery driven jump starter units, widely available for about 50 pounds/dollars

Something more is wrong here. Most any 12v car battery in good condition has sufficient CCA to jump start a motorcycle. Positive to positive. Negative to negative. I don’t do ground as I wonder if computer systems might register a fault. Two 12v batteries linked in parallel produces more amps but the same volts.

So either your MC battery is so depleted the CANBUS won’t let it start or you didn’t maintain connection long enough to resolve the problem. When jumping a car, I frequently leave the jumpers connected for a few seconds to ensure the onboard systems are charging the system before disconnecting. Did you try putting the battery on a trickle charger to recharge it?

I am amazed that the tiny battery from a bluetooth connection on your helmet could drain a healthy battery in a couple of days. I am aware that older 1200RSs have a smaller battery but I suspect that there is another factor in play here. Either something else is/was draining the battery (alarm?) or the battery is on its way out. In any event, as already noted, attaching a 2nd battery in parallel should have done the trick. Sounds like you have a bigger problem somewhere.

P.S. Just noticed you have both a 1200 and a 1250. Which was it? Logically the 1250 given where you are posting.

Chris

Zitat von Aussie Import im Beitrag #1

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Has anyone actually jump started the RS?

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My 2007 BMW R1200R died while I was visiting my brother two years after I bought the bike. When I went to start the R12R after my visit the starter turned over for a moment and then died, along with the instrument display. We were able to start the bike with a jump start from my brother's truck, but as soon as I removed the cables the bike died. Eventually, I had to have it towed to my dealer. It turned out that the German-made, BMW-brand Exice battery had suffered an internal short. Even though the battery was almost 24 months old, it was replaced for free with a new BMW-brand battery, which continued to work until I traded the bike in for my RS. So it would appear that if your battery is shorted out internally, a jump start is not going to help much. You will need to remove the offending battery and replace it with something that works. However, I would think that if the battery is just discharged and is mechanically OK a jump start should get it going and once the charging voltage on the instrument display settles down, you could remove the charging cables and the bike should keep running.

Zitat von Richard230 im Beitrag #8

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My 2007 BMW R1200R died while I was visiting my brother two years after I bought the bike. When I went to start the R12R after my visit the starter turned over for a moment and then died, along with the instrument display. We were able to start the bike with a jump start from my brother's truck, but as soon as I removed the cables the bike died. Eventually, I had to have it towed to my dealer. It turned out that the German-made, BMW-brand Exice battery had suffered an internal short.

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Zitat von wessie im Beitrag #9

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I suspect the lead from the jump start post was not taking enough current to overcome what was being sunk by the battery and that needed by the starter motor.

Did you leave the jump leads connected for a while to allow the voltages in the bike battery and slave battery to equalise?

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Zitat von Richard230 im Beitrag #11

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my dealer told me that BMW had apparently received a bad batch of batteries and replaced both of them for free, even though the R12R's battery was almost 2 years old.

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About a year ago, maybe Feb 2020, I had to jump my bike from my Mazda 3i sedan. I knew the original battery on my 2016 RS was acting up. I had pulled into a local chain pharmacy (CVS)'s drive-through to pick up a prescription.
And then it died and wouldn't start. It was intermittently not starting 100% for a little while- several times. Thank god it was a bike, and I could push it. I left it there overnight with approval, behind the store, near the backdoor.
I brought the car the next day with cables and tools- and new Lab pup. Maybe I had to reposition the alligator "clips" a few times. I read the manual to be sure I was attaching + in the right place on the bike. Whenever I jump a bad vehicle, I usually put the - lead on that vehicle's frame or ground point, look for a spark to jump. It worked, and then I rode home. Ubered back to the car (and the doggie!- shame on me!). Bought and picked up the new AGM O'Reilly's chain battery and installed at home.

The original batteries in these things I kind of think are for shit.

You're list of usual reasons likely accounts for some of the problems, but I'll reiterate a theory based on my experience, as it seems a large number of veteran riders and mechanics are running into early failures.

My OE battery was damaged by recurrent and nearly full parasitic drain from a computer board that wasn't shutting down. The bike was built around April 2015 and I bought it in November 2015. The problem was picked up by an alert salesman (who spends time rotating chargers around the show room). After diagnosis and discussion with the mother ship, the board was replaced before sale.

I suspect my bike is not the only one that has had a faulty parasitic board.