dead battery - now what?

[daveywavey]

Ok I'm an idiot: parked my stock r1150r in Oct. without doing proper maintenance and now I'm stuck - the battery did not hold it's charge (duh!). I've got no accessory port, and have just looked in the manual abt how to get at the battery. Yikes! I haven't started the job yet, but could someone quickly tell me if there is a shortcut to removing the entire gas tank to get at the battery posts for a trickle charger? Thanks IA

[sweatmark]

Removing fuel tank is not difficult. I have a YouTube video showing same.

Alternative is to use starter motor terminals, which will include the hearbox ground in the charging path but should still work. Careful with those terminals once the battery is charged!

If using non-sealed battery, would recommend pulling tank to top off cells. I had one BMW battery "boil over" 10+ years ago, and the acid damage took a while to clean up.

[DJ Downunder]

Do the instrument lights come on? .. If so I would try a bump start.

Second gear.. Clutch in.. Push bike (down hill if poss) and simultaneously drop the clutch and bounce on the seat to help prevent rear wheel lock up.. I've done this a few times without a problem.

DJ

[Buckster]

http://r1150r.org/board/viewtopic.php?t ... jump+start
I don't know if this helps or not. I saved this a while ago. Looks like the pictures are gone now. You may want to do a search.
Taking the tank off isn't hard. just follow the instructions in your owners manual. I don't bother trying to get any of the gas out either. Make sure you mark one of the 2 lines that you have to disconnect with the little barb fittings as you do not want to get these crossed over when re-assembling. You can also avoid this by leaving the barb in the bottom hose on one and the top hose on the other. One of the lines is a tank vent hose and the other is an overflow hose.

[grwrockster]

I'd expect that if the battery has been fully discharged for a while that it's probably going to have to be replaced.

Having said that - if you want to try charging it first it is possible to get onto the terminals if you are very careful with the +ive connection not shorting on the tank underside when connecting a charger.

You can remove the tank securing bolt and then lift up and then prop the tank up at the rear with a block of wood or similar - this gives you just enough room to get at the battery.

If you do disconnect the battery (and if its dead flat then its the same deal), then after you recharge it / replace it you need to turn on the ignition afterwards, and then fully open and close the throttle twice with the engine off to reset the motronic system I believe.

[riceburner]

Jump start the bike, then take it for at least an hours ride. The best charger for the battery is the one on the bike.

Jumping is easy - single torx tool to remove the starter motor cover - plus line to upper terminal on starter, neg line to a bare bolt on the engine somewhere (the entire engine is effectively earth) and DON'T run the car engine - just use the juice available in the battery to get your bike started.

The BMW starter posts that some bikes come with are wired like this - pos to terminal on starter, neg is a large bolt head on the engine side.

[riceburner]

I'd expect that if the battery has been fully discharged for a while that it's probably going to have to be replaced.

Having said that - if you want to try charging it first it is possible to get onto the terminals if you are very careful with the +ive connection not shorting on the tank underside when connecting a charger.

You can remove the tank securing bolt and then lift up and then prop the tank up at the rear with a block of wood or similar - this gives you just enough room to get at the battery.

If you do disconnect the battery (and if its dead flat then its the same deal), then after you recharge it / replace it you need to turn on the ignition afterwards, and then fully open and close the throttle twice with the engine off to reset the motronic system I believe.

GW - the throttle movement after reconnecting the battery is just to confirm the range of movement available - it tends to get reset without the battery power. The Motronic computer doesn't lose it's entire memory, luckily!

[daveywavey]

THanks all for the sage advice:

I saw sweatmark's video on tank removal. It is involved but do-able. I also saw the other video (don't you love youtube?) that bypasses the battery and attaches the trickle charger to the starter terminal. I like that much better.

I had power for lights and even the starter motor turned over but not nearly enough to start the bike (I'm in Toronto, it's just a bit above freezing and I parked it 4+ months ago). But I don't think jump starting's an option - no hills nearby. Still, I don't think the battery's dead so I'm thinking trickle charge, followed by regular usage should work fine.

So I'm leaning towards the start post option.

If anyone has any thoughts on that please let me know. Thanks again for allowing me to tap into the collective boxer knowledge base. (and could someone tell me why BMW designed such a great bike with such compromised battery access?)

[Buckster]

[quote (and could someone tell me why BMW designed such a great bike with such compromised battery access?)[/quote]

We've been wondering for years!

[grwrockster]

GW - the throttle movement after reconnecting the battery is just to confirm the range of movement available - it tends to get reset without the battery power. The Motronic computer doesn't lose it's entire memory, luckily!

RB - I wasn't certain about the throttle thing - think maybe I got confused with what to do after a TB?

Jumping is easy - single torx tool to remove the starter motor cover - plus line to upper terminal on starter, neg line to a bare bolt on the engine somewhere (the entire engine is effectively earth) and DON'T run the car engine - just use the juice available in the battery to get your bike started.

The BMW starter posts that some bikes come with are wired like this - pos to terminal on starter, neg is a large bolt head on the engine side.

FWIW - I have the start posts on my '04 Rock. But.... when my battery was on the way out, I found that the posts didn't carry enough current to start the bike off jump leads. I then moved the jumper leads direct to the battery and the engine cranked fast enough to start no problem. So... it might be that if the battery is no good that the direct to starter motor jump connection isn't effective (though I cant see why it should make any difference - but it did).