The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: rev_mook on July 25, 2012, 05:44:46 PM
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Hey all, It seems to me that I have a current leak somewhere within the electrical system of the bike. The wiring is all completely stock and unmodified except for a GPS power cable which is connected straight to the battery terminals. The GPS is off the bike when it is parked.
Not too long ago I got a new battery which was recommended in this thread:
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1336749662
If the bike sits for 5 or so days, it becomes weak and won't turn over the machine. Is this expected behavior? 5 days dosen't seem that long. Is there a common part which would cause a current leak?
Last time this happened, I jump started the bike with my van then rode the 15 miles to work. The battery was fine after that. Today I jump start, then ride to work and the battery is still too weak to turn the engine over. The GEN lamp is not illuminated and I kept the motor speed over 3k for the majority of the commute.
When I get to a multimeter, I will test the voltage of the battery with the bike off and running, as well as measure any current that might be escaping. Anything else I should test? Perhaps I should remove the tank and clean the contacts on all the connections?
I'm concerned now because I'm about to go on a very long trip with this bike. :-/
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Does the GEN lamp come on when you turn the key to the ON position, before starting the engine ?
To test the alternator output, you need to fully charge the battery, start the engine and bring the rpm's up to about the 4000 area, the alternator should be putting out it's maximum in this general area .
Usual range is 13.9-14.2 volts, or there abouts, all bikes are a bit different .
About the only common thing that I can think of, causing a drain on the battery, would be a bad diode on the diode board just above the alternator .
But usually the GEN light will glow dimly it a diode has failed and allows electrical flow in both directions, instead of acting like a check valve and allowing electricasl flow in one direction .
A good cleaning and checking of the connections is a good idea .
There's one connection that gets overlooked due to it's location, it's the connection fro the alternator output, to the starter, it's a bit odd, the positive cable from the battery goes to the post on the starter, the wire from the alternator, goes on the same post .
This is hidden by the top cover of the engine .
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My GEN light is on when I turn the key, just before starting it and it does not glow dimly when the motors speed is around idle; a little over 1K RPMs.
I took the freeway home from work today, and when I got to my destination, the battery had enough juice to crank the engine and start. "Great!" I thought, I took slow backroads to work this morning so it must not have charged it enough.
I did a couple trips around town after work, and each time the battery had enough juice to start, but this evening while getting dinner, the battery was completely flat again! Something is fishy. I went to find my multi-meter but my shop is to much of a mess right now. I'll use the meter at work to see if there is a current vampire in the bike. I might also try using the old battery to see if it has the same behavior.
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If the bike sits for 5 or so days, it becomes weak and won't turn over the machine.Is this expected behavior?5 days doesn't seem that long.
It's certainly not expected behaviour on a good battery. I would go ahead and check for leakage current with a multimeter but in the mean time I would also fully charge the battery as a jump start and riding to work is never going to do that. Your going to need a fully charged battery anyway to check the charging voltage or the results will be misleading as the voltage will read a low.
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If you don't find anything wrong with the bike, remove the leads from the battery, fully charge it, then let it sit for a few days, reconnect the battery cables and see if you still have the problem .
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Pull the ground lead - cause it's safer- and insert an AMP meter in series with the lead. Start on the highest scale. Don't turn anything on. You should see NO current flow. If you do, there is a path somewhere in your wiring or components which should not bee there. Things happen when things electrical are exposed to the elements. TO check individual components you will have to reconnect the battery ground and then insert the meter in series with the "hot" lead going to the battery from each part. Doing it this way is because some parts, like bulb sockets, ect, are grounded to the frame and the negative (ground) lead can't be lifted without removing the part from the bike. I suspect the battery, though. DOn't go crazy with this test until you have tried charging the battery and seeing if it will LOSE it's charge just sitting, out of the bike.
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Thanks for everyone's input. It's really appreciated.
This morning I checked current leakage with my multi-meter and it reads as expected (.000mA) with no load. I don't have a fancy meter that will read uA so there is a possibility that a tiny amount of current is escaping, however I believe this to be unlikely.
The battery is charging now. More testing when it's full of electrons.
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Sounds like it's just intermittently not charging..OR intermittently parasitic.... Which might be some more connections you've overlooked...
I'd start disconnecting the battery when you're not riding... And then see if it starts every time.. Carry your meter along and measure the voltage...Check the current with the switch off too..Turn the switch off and on and see if something might be "sticking". Your problem is obviously intermittent and only consistently testing and retesting until the culprit is found is going to work... It'll leave you stranded at the worst possible time...
Evil electrical gremlins...You'll get there just stay with it..
John
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Intermittent electrical issues are the absolute worst. I would rather have half a dozen known issues than one 'sometimes yes-sometimes no' electrical problem.
Keep after it. It's an Airhead... simple by design.
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So often, I ride slow on back roads, and do pretty short trips; the engine speed doesn't get that high. It seems like I'm just taking power from the battery each time I start and not really replacing it do to the nature of these type of rides.
Freeway riding tho, I keep the engine speed around 4~5K, and the engine cranks fast when I start it next.
So, I think my flat battery is just because I ride slow and go on short trips, then not ride it for a week..... Or there is something intermittent. It's been behaving well this week tho. :)
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If less than 3K rpm. battery is not charging at max. Short trips in town can lead to a dead battery-even a brand new well charged battery. Stop and go city traffic is worse.
Bob
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To avoid morning start-up surprises. invest in a Deltran Battery Tender Jr. I have a couple of these units and they maintain the bike's batteries at full charge. The supplied quick disconnect is cake.
I bought my newest through Competition Accessories and their ad on eBay.
http://www.compacc.com/p/Deltran-Battery-Tender-Junior-6-Volt-or-12-Volt/1122002 Free shipping and no tax.
Here's a link to the current eBay "tenders". Free shipping for some.
http://www.ebay.com/sch/Car-Truck-Parts-/6030/i.html?_nkw=deltran%20battery%20tender%20jr&_trksid=p2050885.m1602
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I've been using these for about two years now, have four, one for a car and three for bikes .
http://www.harborfreight.com/automotive-motorcycle/battery/15-amp-three-stage-onboard-battery-charger-maintainer-99857.html
With Harbor Freight's usual 20% off coupons you can get them for $15 if you have a store near you .
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Since I can't update the sticky thread - I just bought one of the Gruber Power (battery) 58AGS-whatever.
$33 shipped to Ohio. I'm happy with that price. I have not yet test fit it yet.
-John
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I just rode from Los Angeles up to Portland along the coast, and I haven't had any battery issues. At this point I'm sure my problem was just the stop and go traffic down in LA. I have a little battery tender but unfortunately I don't really have easy off street parking.
Next stop, Chicago!
:D