new battery dead in a month... SOLVED

[KeithB]

I installed a new battery in the R1550R and charged it correctly. Within a month of sitting idle, the battery is so dead it won't start the bike. Been through this cycle twice now.
The battery has been properly load tested as good so I suspect a parasytic load is draining it. Checked (with ammeter) across the fuses and found only 1 10ma draw (very small)with the key off. Disabled that fuse and am waiting to see what happens.
Next I will check directly from the battery main terminals and have not done so yet 'cause getting to the battery is a PITA.

Looking for any other ideas from someone who may have had this problem.

Perhaps this is normal on the BMW but my FJR1300 can sit for a long time and still kick over. Same make of battery too.

[AZBMWRIDER]

In my experience, your situation doesn't sound too unusual .
I've had a few spells where I did not ride the bike for 4-6 weeks, or have a battery tender / maintainer connected and the battery and saw the same thing .
Even with the ignition switch in the off position, there is still power being used by the bike from the battery .
The only thing I can think of now, is the clock is powered all the time, don't know if any other circuits are powered .
My suggestion, get a battery tender and connect it to the accessory outlet on the starter cover, if you have one installed there .

[KeithB]

I do have a battery tender but it's rather a PITA as the bike is in an underground parking lot in my building. Nowhere near an outlet.
My wife rides it sporadically and , of course, it's dead when she wants to ride.
Not an insurmountable problem.

Anyway, I had a chance to do some more testing right from the battery terminal.
With key off, there is a 1.5 ma load (extremely small)to the "computer" and a 10.5 ma load to some kind of voltage tester the PO installed.
Pulled the fuse on the voltage tester and will see how it goes.
I have a number of bikes and this is the only one that kills a battery this fast.
Will post results of test in progress later this month.

[swamper]

Thanks for the reminder to hook up my Battery Charger. My Battery usually goes about 6 weeks before it won't have enough power to start. Weather here has prevented my normal riding schedule but looks like the weekend coming up will be good for a ride. The one problem with the Battery Tender is that it only charges to 80 %. I may hook up my other charger at the 2 amp charge setting for a few hours instead of the tender. It has the same plug in as a tender.

[KeithB]

I should have been more specific as I do use a 2 amp CHARGER to keep the batteries in the bikes topped up.
It just seems a bit odd that the BMW battery dies before the one in my FJR 1300.

Anyway, will report on findings at 3 or 4 weeks sitting in the garage having disconnected the POs voltage metering device.

[Roger 04 rt]

Keith. That 10.5 mA draw is way too high. Total draw should be under 3mA and less on your bike since you don't have an RID. You'll have to get rid of that monitor. What type of battery do you have?

[KeithB]

I have pulled the supply fuse to the "voltage monitor" and will see how it goes.
The only other draw is 1.5 mA to the computer. That's not an issue.
It's a Yuasa YT19BL-BS maintenance free.

[KeithB]

Went to start the bike today after 3 weeks parked and it fired up with plenty of juice from the battery.
Seems the "voltage tester" that the PO installed was the problem.

[CycleRob]

KeithB, The Voltage tester device is really great as a charging system monitor -IF- it is wired to display the voltage only when the key is on (engine running). The PO found a 12V source and used it, maybe even thinking the tiny 10ma draw would be OK. It is NOT OK for key off storage.

[KeithB]

KeithB, It is NOT OK for key off storage.

Right.
However, I don't see any use for it as the LED is mounted in the side of the bike where you can't see it while riding.
Have not needed it on (many) of my other bikes so ... it's outta here!

[CycleRob]

KeithB,
I would not throw away the LED voltage monitor as it is valuable. Blaming it for killing your battery is misplaced, as it was the fault of the PO made the "always on" wiring mistake. I would relocate it to where it is visible while riding and wire it to the 12V power for the front parking light bulb.
You may have missed the important part of my post: "The Voltage tester device is really great as a charging system monitor". Granted, the R1150R has a world class, powerful and reliable, car-type 700 Watt alternator that compared to all other bike alternators . . . is the King. The fact you did not "need" one on your other bikes may not have taken into consideration the number of batteries you have bought that were unknowingly abused on a regular basis by Farkels like driving lights, heated clothing and heated grips, discharging the battery while idling for several time periods. It is especially bad on short trips and just before the bike is shut off! Add to that if the bike is started up to put it in the garage, essentially a 15 second 25 foot ride. All those behaviors described cumulatively cause battery sulfation, which reduces the battery's full charge capacity. Here is a weblink to explain it all:

http://batteryuniversity.com/learn/arti ... prevent_it

BTW, I have my very same RadioShack) 3 color LED voltmeter that was installed on my last 3 bikes to monitor their charging systems. On the first bike, a 1990 VX-800 Suzuki, it informed me when one of the 3 yellow wires from the alternator to the voltage regulator FRIED it's connector terminal, causing a short circuit and ZERO charging! I quickly knew to turn off the headlight and get home immediately to fix it. The BMW battery in my 2009 F800ST lasted 6 years 9 months, when I noticed the cold engine start started to be infinitesimally slower.

.

[KeithB]

I take your point(s), and they are valid, but if I am going to remove this device it's not going to make it back on the bike.
A charging system monitor is nice but if I really want that, I would go for a volt meter.
I baffles me why the PO mounted the LED in a place where you can't see it while riding!
I can understand the wiring error as a lot of people have no idea about electrics.
Anyway, all good and moving on