The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: diggers on July 21, 2008, 03:07:07 AM
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I have an issue with my battery! I bought my bike about 3 months ago, the battery was on it's last legs so I bought a new one about a month ago, and it appears to be on the way out also!
I recall reading somewhere that the R65's eat batteries if used for alot of short run commutes, due to the light being on all the time and alot of short runs equals not much time for the alternator to do its stuff. I commute about 20km (that's about 12 miles for you Uncle Sam lads!) each way. Could this be the problem?
Possibly the alternator is tired and not working properly. Is there an easy test for this I can do myself with some simple equipment?
I also recall reading about an upgrade of something electrical that takes care of the "lots of short commuting/not much charging" problem. Can anyone help me out there?
Remember to speak slowly!
I'm really happy with my shiny black paint job, just have to the thing started to show it off!!
Cheers from NZ!
;D
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First thing I'd check is the charge voltages, very easy to do with a multimeter.
Connect the multimeter (set to volts) direct to the battery terminals, making sure the main connections are are clean and tight. The voltage should be around 12v. Start the engine and the volts at idle may be around 11.5v, start reving the engine, and by 3500 rpm the voltage should settle at about 13.8v or slightly above regardless of the headlight on or off. If it refuses to raise higher than that, even with reving higher, there may be a problem with the charging system.
A daily 20km run each way should be enough to keep the battery charged, as long as there are no extended periods of stop start during the run. It may be better to invest in a small float charger that can simply plug into the accessory socket on the side of the bike, no need to disconnect the battery. It's what I use to keep the battery at its peak especially during winter.
I wouldn't try to fit any sort of what is euphemistically called 'high o/p regulator', as they can cause more damage as they simply boost the charge voltage and can over charge the battery on any longer runs.
The alternator doesn't actually 'grow tired', but can be a collection of cheap fixes, such as connections, that can have everything running fine. Try the above check first and get back to us with the results.
I hope I spoke s l o w l y enough for a Kiwi to understand!!
Bill............................;-)
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I would also look closely at the type of battery that you bought. Some of the old wet cell types can fail fairly quickly (but shouldn't fail that quick). I have had good luck with AGM (Advanced Glass Mat) batteries which hold their acid in fiberglass mats and don't need refilling. Speaking of refilling...did you check to see how much acid is in your battery cells (assuming you have a wet cell type)? If your battery acid level is down you may be overcharging the battery (possibly a bad regulator) or the battery you bought may be a bad one.
Whatever you do I would buy a battery maintainer (a smart one that monitors your voltage and adjusts the charge automatically) and use it after each ride.
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Your diode/retifier board can have a bad diode cause a drain on the battery when the key is off. You can hook up a mulit meter in mill amps between the positive lead and positive battery post and see how many mill amps. It should be realy small but any will drain the battery over time. I have had this many time over the years on all by bikes.
Don
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Thanks for your replies. I'll start with the multi meter first, when I buy one tomorrow!
Bill, some clarification: If the volts read as you suggest (13.8v or so at 3500rpm), does that then indicate the alternator is charging the system correctly?
Also where is the "accessory socket on the side of the bike"? Didn't know I had one!!
Cheers
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Yes, that's right, around 13.8v maybe a little higher, most certainly not much lower.
The accessory socket is an indefinable as on some years/models they were fitted as standard, on others they were optional when bought and may not be fitted. If you do have one it will be on the left hand side attached to the rear sub frame near the battery, a small black plastic cap will cover the opening. However, all is not lost as they can be bought second hand and fitted, or a maker like NARVA still make the same fitting, and it will only need attaching and wired direct to the battery with a 7.5amp fuse as close to the positive battery post as possible.
Otherwise, most trickle/maintenance chargers (available at motorcycle shops) come with a socket that can be permanently wired to the bike in the same way as the above. This will match a plug that attaches to the charger and can be plugged in and out as required.
Bill..........................;-)
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Also where is the "accessory socket on the side of the bike"? Didn't know I had one!!
With the understanding that you guys are located on the other side of the world and your bikes may be quite different from the American market, my 1981 R65 has an accessory terminal on the right side of the main frame tube just aft of the relay attach points. I used the unswitched 12v hot wire as a power tap for the new Vapor digital instrumentation on my bike.
(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fi196.photobucket.com%2Falbums%2Faa1%2Fmontmil%2FpowerwireVapor.jpg&hash=15c5008a70dd2173a1f479268499c1d1c3519b5d)
The accessory socket is the light blue terminal. Positioned near the air filter box. The black plastic box behind the acc terminal is the fuse box. Hope this is helpful to you.
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That's not the "accessory" socket Bill is referring to. All of our bikes have the socket and it's bracket attaches to the L/H upper shock absorber bolt and is accessible from the outside of the bike to plug heated clothing, chargers, etc. into.
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That's not the "accessory" socket Bill is referring to. All of our bikes have the socket and it's bracket attaches to the L/H upper shock absorber bolt and is accessible from the outside of the bike to plug heated clothing, chargers, etc. into.
I went and looked. Ain't nuttin' like dat on my scooter so don't guess "All our bikes" do after all. :o
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The accessory plug was not standard for the R65.
Don
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Monte, when I said "our" I meant all of them that we have. Sorry for your low-end machine! ;-) Hehe, the devil made me say that!!! [smiley=evil.gif]
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Cheers Monte. My R65 was new in the US in 81. Imported into NZ in 86. So it should have the same stuff as yours! I'll have a look.
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I purchased my '81 R65 new from the dealer in January, 1981, and the bike did not come equipped with an accessory socket .
There is an unused connector under the tank that has an unswitched 'hot' connection, headlight connection, and turn directional connection, but that is the extent of additional wiring connections.
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I purchased my '81 R65 new from the dealer in January, 1981, and the bike did not come equipped with an accessory socket . There is an unused connector under the tank that has an unswitched 'hot' connection, headlight connection, and turn directional connection, but that is the extent of additional wiring connections.
As to Digger's looking for a simple hookup for a battery charger/monitor - the accessory plug, with the unswitched hot lead and any convenient ground point- would be a simple install. I have a two-wire, insulated plug that I occasionally use for my battery bump-up. The charger lead lives in the underseat tool tray.
Maybe some of Mike-da-Bike's battery magic whiffle dust and a trickle charger will get DiggerMan on the road. Whatcha think, Kiwi? [smiley=thumbup.gif]
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My 1980 R65 was eating batteries .....it has a sidecar with an extra head light and taillight. Tried putting a Gel battery in and LED taillights .........which helped some. The LED taillights were even brighter for less drain. But in the end...........it just wasn’t enough for all my stop and go driving in town. Some ninety percent of my riding is running errands around town.............My poor old battery was always drained. An Omega alternator upgrade was my final cure. If you have a lot of electric eating accessories....or a lot of stop and go riding........or both....look into the Omega. Ended my problems........present battery about two years old.........and doing good.
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I added the accessory plug to mine, just behind the battery cover on the left side, in order to keep the battery topped up with a Battery Tender & allow me to add additional electric goodies in the future.
Here's the link to realoem. the kit should be available for the dual shock models as well.
http://www.realoem.com/bmw/showparts.do?model=0462&mospid=47892&btnr=61_0255&hg=61&fg=30
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Beautiful rig, Scotty! [smiley=thumbsup.gif]
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I just did the multi meter thing. I got 11.3v turned off. Once the bike was going it rose to 12.4v at about the 3500rpm mark. From what I'm told it sounds like not enough alternator action is happening and therefore it may be faulty. That sound correct to you knowledgable guys?
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Before I started replacing costly components, I would follow airhead's advice on checking electrical connections in the charging system for condition (corrosion, loose wires in crimped on connectors, loose connections where they are held on with fasteners, etc.) .
When I lived in Chicago, when I was using my R65 to commute to work, it was 7 miles and 15 traffic lights, if I didn't take the bike out on my days off and run it at highway speeds for an hour or so, or put the battery on charge, on the 8th work day, the battery would be discharged to the point that the starter would not rotate.
Since moving to Phoenix 15 years ago, my work commute is 12 miles, with 10 of them urban expressway, and I have not had a problem with battery charging with this 'new' commute.
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Thanks for the advice Bob! Will try that next. Cheers ;)
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I just did the multi meter thing. I got 11.3v turned off. Once the bike was going it rose to 12.4v at about the 3500rpm mark. From what I'm told it sounds like not enough alternator action is happening and therefore it may be faulty. That sound correct to you knowledgable guys?
Sounds like you have the basis of a decent fault to look for there. My guess would either be a duff diode board, bad brushes, or a stuffed regulator.
Do you have access to known good examples of these to temporarily substitute (one at a time)? If not, here is a download of the BMW procedures for diagnosing further, noting of course your possible limited experience working in this area. If so, get back and we can lead you through.
http://www.mediafire.com/?3m1hy4mpwsi
Bill........................;-)
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Cheers Bill. I'll print off the download and have a go. I'm already verging towards the "time to go to an auto sparky!" position, but I'll have a crack and see how far I get!
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Hey Monte, I've made some progress: I found the blue connector box thing under the seat!
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Hey Monte, I've made some progress: I found the blue connector box thing under the seat!
Outstanding! You've got power there for a battery tender or similar. Just don't post a photo of it. ::)
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I just did the multi meter thing. I got 11.3v turned off. Once the bike was going it rose to 12.4v at about the 3500rpm mark. From what I'm told it sounds like not enough alternator action is happening and therefore it may be faulty. That sound correct to you knowledgable guys?
I noticed in the trouble shooting download that if the voltage reading is significantly below 13.5V to examine the cable connection. Thats where I'd start.
Bill, Have any more gems like that download hidden away?
rich
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Well I'm not exactly sure I did what I thought I did, but I think I managed to test the output at the diode board and also the output from the D+ wire that goes to the regulator. Output from both of those was 11.3v, which is the same as the battery output. I think that means that both of those things are ok, leaving a faulty alternator as the issue.
Anyway I took it to a motorcycle auto sparky today. I'll let you know what the outcome is. Along with a bill I've actually gained some knowledge about the electrics of my machine! Thanks to you guys who have helped me out with advice and tips. From my perpsective it's much appreciated! I often marvel at the ability to exchange tips, chit chat and nonsense with people from all over the world that I've never met, but feel a kindred spirit with! Cheers!
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The auto sparky did his thing and told me the voltage regulator had done its time. Alternator and diode board are OK. Come in one new voltage regulator!
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Diggers, it's great to hear that someone actually found your problem that wasn't well versed on BMW motorcycle charging systems.
At least it won't cost you too much to replace the regulator, and it is a quick replace type part.
I have never seen in any troubleshooting guide, about a voltage value of the voltage that leaves the regulator and goes to the brushes in the alternator.
Seems to me that if at peak engine speed, say 4,000 rpm if the voltage being applied to the rotor is insufficient, or below a certain value, it would immediately point to a regulator problem.
All I can find is a reference to power, or voltage available even in Motorrad Elektrik's charging manual.
Anybody ever hear of a certain voltage value before ?