The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Luca on May 16, 2016, 06:13:28 PM
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Rode to work the other morning and the bike fired up just fine. Stopped for breakfast along the way and it started up great again. 5 hours later I went to fire the bike up and I got one tiny click. None of the idiot lights came on, so I thought maybe the killswitch was the culprit. Jumped it to no avail, then realized that it wasn't the killswitch because the headlight wasn't coming on either. Replaced the fuses even though they were fine (interestingly, my original fuses fit better than the replacement from Autozone) Next I checked the ignition as I had been in there recently when I installed the factory optional clock. Everything looked good.
Got a ride home and went back after hours with my truck. I did the simple test that I should have done before... I load tested the battery with the shops Chicago Electric load tester. Though it showed 12.6 volts initially, the second you loaded the battery the gauge swung all the way down to zero. The battery could supply so little current that when I turned the ignition to the on position, there wasn't enough juice to keep that little digital clock going (and I've even got an LED tail lamp assembly).
I've never seen a battery fail that quickly, and just checking with a dc voltmeter would not have revealed the problem. Ordered a Staab replacement. Our 5% forum discount still works!
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Details on the failed battery? Age? Sloshed, AGM or...?
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AGM/VRLA battery of the Scorpion brand. Purchased from Batterystuff.com when I first got my beemer on the road just under 4 years ago. I was pretty lousy with maintenance... meaning I only charged the battery once, which was when I ran it down trying to start an R60. Otherwise, it got put away every fall/early winter and wasn't touched until the spring, when it would dutifully wake up sleeping beauty.
All in all it was a good battery, I was just surprised at how suddenly it died. Batterystuff still sells them, and they have free priority usps shipping. I think their new batteries have a few more amp hours and I thought I spent more money on mine than what they currently go for, but who knows.
Still, the Staab is a few bucks cheaper, so I decided to go with that. The Gruber battery is a little less, but their shipping costs more and the Staab has a little more power.
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4 years is impressive life from any motorcycle battery, I only got a year from my first foray into the world of "gel" batteries. I've had the one int he R65 now for just over a year and (touch wood) it is going strong.
"Going over the cliff" is apparently the preferred failure mode of gel batteries.
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What happens is the terminal connection breaks in the battery the electrolyte carries a small amount of current to operate a volt meter but nothing else. vibration can cause this.
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Just for info, the headlight does not have a fuse .
Batteries don't like to be neglected, even AGM 's .
I'm lucky to get 30 months from a battery here with the incessant heat and they don't give any warning of impending failure, just like your battery did .
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I'm going to throw my two cents into this discussion.
I worked for years at a Harley dealer, and it was not all that uncommon to be swapping batteries out that were 5-10/years old. Anything less than that was a red flag to start checking things over.
These are stock Harley brand AGM batteries. Nothing fancy.
Same with the charging systems on Harleys.
So, if AGM batteries aren't lasting much more than a couple of years, or less, I would say it's time to either choose a different brand of battery, or start going through the charging system.
I'm not new to motorcycles, but am new to these R65's, so if my thinking doesn't apply, someone please educate me. Nothing like cramming for a test!
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just checking with a dc voltmeter would not have revealed the problem.
You can use just a volt meter and your starting system to test your battery.
You leave it in the vehicle and test the voltage during cranking,
It would have done exactly the same as it did with the load tester .
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Hello,
An AGM battery, after eliminating the surface charge it gets from the tender (*), is at :
12.8 V --- 100% charge
12.7V ---90% charge
12.6 V ---80 %charge
12.5 V ---70 % charge
12.4 V ---60%charge
12.3V --- 50% charge.
Under 12.3 V percentages are not reliable. AGM batteries die from vibration. Small lead chips become loose and can make shorts internally. This discharge one element quite rapidly and kill the element. And of course, the reduced lead surface reduce the capacity of this element. Nowadays, there is less and less lead in a battery so every gram chipped out of the plaque is a significant amount of capacity removed from one element.
(*) right after charging, the battery may be above 13 V even may go up to 14 V. If you let it sleep for some hours (a night is good) you have eliminated this surface charge. If after this night the voltage has fallen below 100 % charge, this means some elements are suffering internal shorts (but not radical) and it is time to fetch a replacement.
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Sudden battery failure is common enough with AGM's but given the low initial price of generic AGM's and the "maintenance regime" 4 years wasn't bad at all. Something like an Odyssey would have to last 10+ years to compete on economic terms. Going for a cheap generic again is good policy.
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The low-priced Stabb AGM in my 1981 R65 lasted over five years. Besides installing a newer, higher output voltage regulator -a good idea with AGM batteries as they enjoy a slightly higher charge rate- I would plug in a Battery Tender Jr for a couple days each week.
When the battery gave up the ghost, it did so within one day.
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There was also the winter before last when I used the battery to start my frankensnowblower with a 16hp briggs opposed twin on it. There was no charging system going to it... and i might have let it fall out of its tray and get tangled up in a wheel whilst the cables were still attached [smiley=whistling.gif]
maybe I'll take care of the next one :-[
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As I was reading I had to check the author of the post, sounded exactly like what I wrote when my last AGM failed. They go from "go" to "no go" faster than anything I've ever seen. Most stuff at least slides across the pavement!