The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: georgesgiralt on January 18, 2014, 05:31:13 AM
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Hello !
I switched for a new battery (flooded, Chinese, cheap) about one year and a half ago.
Since a couple of weeks, I have a problem :
The bike starts fine in the morning because I put the battery on the Optimate at night. Then at noon when I want to get the bike for the lunch, she sometimes fail to start because the starter lacks energy. Starting with the kick starter is fine though.
On the evening, when I want to go home from work, same at at midday.
At first I thought that the alternator was not charging enough. So I checked the rotor, regulator, brushes, and diode board. I ride with the eye on the voltmeter ;-) Everything is fine....
So yesterday I resigned myself to buy a new battery. I ride to the big shop which usually provides me with them at cheap. (but not last time...)
The tech guy looked at the bike with a voltmeter, an ammeter, and a battery testing device.
He said to me that the charging system was fine. That the battery was fine because it can give 215 A peak current, and that I has 0.6A current with the contact OFF... So for him it was normal that the battery dries out... We unplugged the clock but this changed nothing. He refused to sell me a new one...
Yesterday afternoon and this morning, I've checked everything electrical on the bike. I do not find any leak. Everything plugged on and contact off my measuring give between 0.2 and 0.05 mA .. So the clock needs power but not so much.
I removed the contact switch to give it a clean and, of course, this changed nothing... So I'm seeking for your advice here ...Boy, this is frustrating and time consuming !
As always, your collective wisdom is vastly useful !
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The bike starts fine in the morning because you leave it on the Optimate overnight. I'm assuming an Optimate is a charger, if you don't put it on the charger overnight, will it start in the morning? If not, then the battery either is being drained or won't hold a charge on its own.
Starting with the battery fully charged, try disconnecting the negative battery terminal overnight and see if it will start in the morning.
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I agree. Try disconnecting the battery and see if it starts in the morning.
That 0.6A drain that the battery guy measured would certainly flatten the battery but it must be an intermittent fault if you are now only measuring 0.2 to 0.05 milliamps.
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Might check your cables. They corrode internally and even though they look good they aren't. This cured my bike with the same issue.
motoelectric.com fixed me up.
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If you have a cable attached to the battery with a quick connect attachment for plugging in the charger I'd take a careful look at it - you might have a crack or worn spot on the insulation that is intermittently contacting the frame or other metal part somewhere under the seat. 600mA is much too high of a current draw for only a clock, provided that the clock is working normally. You don't have any other devices that are "on" while the ignition is off, such as an alarm system, do you?
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So, I've followed part of your advices. I unplugged the battery from the negative big wire. Will check tomorrow how things went.
As I let the fused cable from the charger I may get the 600 mA draw... Will see.
I have a "new" main wiring but the headlight part had been removed to fit on another bike so before using this up I have to make a new headlight harness... (and auto parts store in my city do not carry the parts they used to years ago. May have something related to the recent cars being impossible to fix by the average home mechanics... )
I hope I won't put the bike on fire...
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A diode on the diode board on it's way to failing can cause ' leakage ' and discharge the battery .
I agree with removing the cables from the battery and see what result you get in the morning .
To isolate the diode board for troubleshooting, remove the red output wire from the diode board to take the diodes out of the circuit .
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I'd be looking for the .6A drain. And it appears to be an intermittent fault. :-(
Nothing like chasing down an intermittent electrical fault!
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So week-end is history.
I spent hours verifying and checking things up to no avail. I've cleaned the starter relay contacts, and the ignition switch contacts. All wires look clean and insulation resistance is very very high. Charged the battery yesterday and let it sit on the bench. It has lost a little less than 10 % of it's charge in 24 hours. So maybe something is loose inside the battery producing a leak after a good shake...
Tonight the bike is in shape to run and the battery is on the Optimate tender as I've to be at work at 7 am tomorrow...
Will report if the bike continues to act stupid or if I find something... Thanks for the advices given !
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Have you checked the specific gravity of the electrolyte in each cell of the battery after fully charging it ??
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It has lost a little less than 10 % of it's charge in 24 hours
It might not be as bad as you think. How did you measure the 10% ? If you measured the voltage immediately after charging then that is not a valid method as you have to wait for the surface charge to dissapate. I would charge it, leave at least 12 hours then measure the voltage, leave another 24 hours and measure again.
It depends on the type of battery but for a wet cell O.2 volts represents 25% discharge so if we start at 12.65 Volts 12.45 Volts represents 75% charged. So 10% discharge would be indicated by a fall of less than 0.1 volts from the fully charged and then rested voltage. This would not be easy to measure accurately in terms of being sure that the surface charge had fully dissapted before the first measurement was taken.
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You may want to take a second and closer look at your starter. I had similar symptoms several years ago (ok start in am after battery on charger overnight, questionable starting at mid-day or after work). It turned out that the starter was pretty much shot - turned the engine but not strong enough to turn it enough to start. I replaced the starter, and the problem went away.
k_enn
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You brought up a good point k_enn !!!! [smiley=thumbsup.gif]
A starter that is lacking lubricant, will use more power than it should .
You can disassemble the starter clean and relubricate it with a few hours of work .
Most of these starters are 30+ years old and the original lubricants are long gone .
I did this to the starter on my '81 R65, didn't see any trace of oil or grease where it should have been .
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Hello !
The starter has been overhauled a few month back. So IMHO it is OK.
The problem, when not starting, is that the battery is low in voltage.
The alternator seems to charge properly (tension goes above 13.7V) and the battery guy found a leak of 0.6A which I can't find anymore.
So this morning I went to work with my multimeter. The battery had been on the tender all night. Starting was easy. Arriving at work, after 10 KM with the headlight, the battery voltage was at 12.46 V... So as it is a flooded type around 70% charge...
As I suspect there is still a leak, I wonder if I will be able to go to lunch...
This is beginning to become unnerving.
Do you know if the alternator can raise it's output voltage and not charge ?
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You know what ?
She didn't start for lunch.
Voltage was at 12.53V before inserting the key into the ignition.
So I looked at the voltmeter when I turned her on. it said 12V (normally it is above that line) so in my mind I thought it was toast... Starter did not run and the colleagues had to push me ....
I'll check this out tonight.
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Do you know if the alternator can raise it's output voltage and not charge ?
No, if the alternator voltage is higher than the battery voltage then a charging current must flow.
The normal behavior of the alternator is for the voltage to fall slightly as the engine warms up. Say it's charging at 13.7 Volts with a cold engine by the the end of the ride it will have fallen to something like 13.4 -13.5 volts. It should still charge though as the technical reason for this voltage slope being built into the voltage regulator is that it's designed to compensate for the batteries internal resistance falling with rising temperature which makes it "easier" to charge.
Could it be that the 0.6 amp current drain only occurs with a hot engine ?
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So, here are the day's results :
As said, no start at noon. The bike had to be pushed to start. So I rode the Honda to return to work.
When out, I came home and measured the leaking current on the R65. 0,1 mA max. (oscillating from 0,01 to 0.1 mA seems the clock does not draw constant current). Battery was around 12.50V. (I rode without headlight at noon and with engine revving). Started the bike and measured the alternator voltage : 14.25 V with only the engine and 13.9V with the headlight both at around 2000 RPM. I checked the residual alternating voltage (just in cas I had an intermittent diode) and the voltmeter gave me less than 0.5V which is not so bad..
Bike started instantly. So I went to the battery shop and bought a FIAMM VRLA (looks like the Tashima AGM battery I once had). Returned home with the new battery in the pannier and with the old running fine.
At the battery dealer we measured the leak : 0.0 A and the current draw of the starter. There was a peak at 300A (which is not uncommon for a Bosch). The guy was very reluctant to sell me a new battery seeing the ease the old one started the bike... As I need to be sure I can depend on the bike I invested...
I'll order a starter relay from BMW just to be sure.
I do hope I will have a trouble free bike now ....
Will keep you posted ;-)
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Three hundred amps is a LOT! Mine don't usually draw more than 100 to 150. I think the starter is your problem.
Try the new battery (since you have it) and see what happens.
There was a thread on Adventure Rider several years back that went for pages and pages and pages -- trying to figure out this one particular bike's electrical problem. It didn't seem like a battery issue at all, but finally out of frustration it was replaced and that fixed the bike!
After that, anytime someone presented an electrical issue the stock answer was "it's the BATTERY!".
So I'm saying, it sure sounds like the starter at this point, but who knows? I will say, that if the battery could flow 300 amps to the starter, it doesn't seem to be too bad off. Perhaps the answer is that the starter draws sooooo much current that the ride to work doesn't recharge it sufficiently to offer up another 300 amps at lunch.
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Hello Wirespokes,
I said that the peak current was 300A when starting not that the starter used that for a long time. It needs around 160 A but the surge starting current is 300A. No battery of this size could sustain such a current for a second or more IMHO.
Monday evening I put the AGM battery on the tender to get it charged. Tuesday morning starting was fine. Ditto at lunch or in the evening. This morning starting was fine... So I save the current for the Optimate .... Will see at noon or tonight ...
I wonder if the old battery has a bit of lead moving inside which could explain why it is fine some times and not at other times. But this still don't explain the leak seen by the battery guy once...
So, for now it seems to be fixed. Wait and see .
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I too initially thought the 300A was high. The 300A surge current if very brief is probably normal though as it's a characteristic of electric motors that they have a current peak while they get up to speed. The specification for our Bosch starter lists a stall current of 320A
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Hello !
At noon, bike started like new ! I had to buy something to eat and bread. 2 stops so two more starts... 5 minutes apart. A breeze !
Back to work, without any problem. Tonight, everything was fine. In the garage, my Chinese multimeter reads 12.96 V just after I've stopped the machine.
So glad I drained gearbox and motor oil and changed filter. Put new oil in the gearbox and in the engine. Started the bike to check oiling and leaks. Still running fine. ;D
I'm confident the problem is solved or near it ! 8-)
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Cool. Fingers crossed for ya.
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Glad to hear the fix was quick and not overly costly .
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So, again, it was the battery.
Isn't it amazing how often a bad battery confuses us into thinking it's something else and CAN'T be the battery?
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Well, I still don't know if the bad battery was the root cause or the consequence !
The battery guy measured 600 mA drain current with it's tool.
I was unable to find why and where this drain came from but it may still be present. Time will tell.
BTW, bike started fine this morning.... but oil filter leaked so she is in the garage 'til tonight ... I'll fix it ...
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Is it possible that when you ride the bike in the morning and then park it you are leaving the ignition in the second position, the one that leaves the parking light on? Or that your voltmeter is drawing current all the time? I put a Wudo 90S fairing on my bike with a clock and voltmeter, using the factory harness, and the battery seemed to drain overnight. Took it off and the problem stopped. Not a lot of room under that ignition switch for all the connectors. On my 83 US spec R65, when the bars are fully turned to the left, the turn signal switch hits the tank bag just enough to turn it on, and that will drain the battery. You might try systematically unplugging lights, one at a time, to see if you can isolate the drain. I think if the alternator wasn't charging you would have a red light on. Could be as simple as a multi pin connector loose or corroded. A wire to one of my turn indicators wore through the insulation and was grounding to the mount. After a while, the fuse would blow, but not instantly, which was irritating. After I found the fault it was so obvious.
Electrical gremilns are maddening...
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No cabling problem nor parking light left on.
As far as I can tell it is a battery problem. With the new battery everything is fine. As per the 600 mA found at the battery dealer, a friend proficient in electronics and measuring devices told me that "using a 300 A meter without contact to measure a so small current is doomed from the start".
So .... I ride, I smile and try to forget the 72 € I left in the pocket of the battery seller ...
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Hello Lads,
The day before yesterday I put the old battery in charge. When done, I let it sit for the night and measured the voltage. According to the chart I've, it has lost 10 % charge sitting on the bench.
Yesterday it was 15 % and today 20 %.
The bike runs fine and start every time with the new AGM battery .... All is well !