BMW G310 R/GS Forum banner
1 - 20 of 48 Posts

·
Registered
Joined
·
582 Posts
Discussion Starter · #1 ·
So at 500 miles my 22 310 had a drippy water pump and was charging at 15 volts.
Dealer took fine care of me, if a long wait for parts. But. BMW and Service manager
agreed 15 volts excessive. Replaced regulator, still 15. Then Service Manager tested the four that the dealer had on lot. All at 15 volts!! So it back to BMW for next step. Doubtful we’ll hear back til Tuesday. Fear is that mothership will say “run it”. SM and I both know that’s bad idea. It will cook the stator and battery and leave me stranded, not to mention the four he’d like to sell in good faith.
I believe the fix is a series regulator over the shunt it has now, unless it’s an internal shorted stator….
If BMW says run it, I’ll pass and install a series regulator on my own dime, little less than $300.
Bother
So test that voltage before leaving lot if buying new. Make them show you. Nothing more than 14.7 volts. If you already have one, for heaven’s sake test your voltage. Overcharging is a slow horrid death as the stator cooks the bat ray and itself. I have to ponder that the “darkness“ some observe in waste oil is actually from cooling a really hot stator. Also check the water pump “tell” hose close while still on lot. Mine was leaking day one for sure, just too slow to see right off. Right when fan came on, a small drip would ooze. Had I looked I would seen it. So slow that even after 500 miles the level was still fine in bottle. Don’t accept a leaky bike Or overcharging one.
 
  • Like
Reactions: G0MYW

·
Registered
G310GS 2018
Joined
·
666 Posts
Difference between 15 Volt and 14.7 Volt is 2%. Checking my voltage regulator wouldn't give me any clear indication of it's proper function. I have three digital multimeters and they all show different values on voltage. The difference is in the figure of 5% between the extreme. For a professional mechanic, that is un-acceptable. For me, it's sufficient. For measuring if a battery needs charging or not it's fine. For checking continuity in a wire, it's good enough. Calibrating the meters isn't worth the money, im my case. That would cost more than the instrument itself.
 

·
Registered
Joined
·
39 Posts
15v isn't good. I haven't looked at the voltage regulator at all but I'm assuming it is regrettably non-adjustable, correct?

From my work with other AGM batteries, manufacturers recommend constant potential charging where the battery accepts charging current inversely proportional to its state-of-charge (taper-to-float). Here's a table I found of recommended voltages for AGM charging with temperature conversion. As you can see the highest permissible voltage is 14.75 when temperatures are below freezing:

Rectangle Font Slope Parallel Pattern


I'll measure my 2022 voltage later today and see what I find.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #5 ·
It all got very funky. The dealer heard back from BMW. “The regulator is set for 14.9 volts there is nothing wrong, probably meter error.” Hmm hmm hmm. Dealer nervous now to sell his stock 14.9 is still too much to have much battery life, assuming stator can handle the load. Mine actually goes over 15v at times, sometimes I see a blip of 14.7 Double funky as the ECU is supposed to register over current and has not given a code yet Or yellow triangle. Why did they approve the new regulator then?
Service manager said “it’s documented, so just ride it and we’ll warrant out what goes on, perhaps BMW knows something we don’t”. He was being a tad bummed, they are primarily a Harley dealer and he’s miffed at the “BMW” method.
I could see where a lithium battery would be okay with higher voltage and perhaps that’s what the engineers were thinking. When home, I’ll check the stator for a short then install a series regulator soon. That should cure over charging. I’ve been stranded before with overcharging and it will happen on a trip, screw that. Easier but more duckets would be to get a lithium battery which I would anyway but not at 500 miles.
At least my water pump is replaced and I’ll pick up the bike today. Riding it will make me feel better. And new to me rear shock coming Monday. Source for series regulator 4 hours away.
Should be sorted in time for a mission In August
Watch that voltage. Note the China meter I installed is reasonably accurate, tested against many meters now.
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #6 ·
So the strange after math. Picked up bike at dealer. Tried to charge for water pump and regulator……ha ha but $850 if anyone interested. Great convo with technician like Service manager he thinks over charging but nothing to do thanks to BMW, even though they did approve a replacement regulator. I rode off a tad bluesy which vanished once in saddle, even a little wheelie action for Harley team hanging out eating donuts. Such a fun bike once suspension dialed. Even better, at speed, the voltage readings were less than I experieced with old regulator!!! A tad high still for taste but less than 15 works for me, I’ll just avoid idling which is easy enough.
 

·
Registered
Joined
·
503 Posts
Interestingly, the TVS shop manual states the RR should regulate "between 14.1v to 14.6v at any RPM and any load."

I'm in the 14.9s idle to 3000 (parked) using multimeter. Using my Konnwei for a charging test, the results are slightly >15v with a "Charging High" test result.

I've been through one BMW stock battery and on my 2nd as a warranty replacement.

Methinks @ARBOLMANO hath stumbled upon something, perhaps.
 

·
Registered
Joined
·
39 Posts
I tested 14.87 with a good Fluke 110 meter. Same at idle all the way up to 5000 rpms.

I'd say that is definitely a little high. I can see where over a period of time that could cook the battery.
 

·
Registered
Joined
·
92 Posts
So the strange after math. Picked up bike at dealer. Tried to charge for water pump and regulator……ha ha but $850 if anyone interested. Great convo with technician like Service manager he thinks over charging but nothing to do thanks to BMW, even though they did approve a replacement regulator. I rode off a tad bluesy which vanished once in saddle, even a little wheelie action for Harley team hanging out eating donuts. Such a fun bike once suspension dialed. Even better, at speed, the voltage readings were less than I experieced with old regulator!!! A tad high still for taste but less than 15 works for me, I’ll just avoid idling which is easy enough.
I fitted a Battery Monitor BM2 this evening, very easy fit.. Interesting to see the readings it was giving off.. you can see them at the end of the thread below.

 

·
Registered
Joined
·
53 Posts
FYI: My brand new 2022 also charges at 14.9V according to my bluetooth voltmeter. I'll ask the mechanic about it when I bring it in for the 600 mile service. The resting voltage is around 13.2V. (Mind you, this is a $40 voltmeter and not some $300 precision device.)
 

·
Registered
Joined
·
503 Posts
FYI: My brand new 2022 also charges at 14.9V according to my bluetooth voltmeter. I'll ask the mechanic about it when I bring it in for the 600 mile service. The resting voltage is around 13.2V. (Mind you, this is a $40 voltmeter and not some $300 precision device.)
I think the theme here is that it's becoming obvious the RR units are built to this spec. Question is, should they have been?

In other words, is BMW covering for a supplier slip up, when they claim 14.9v is fine? Or, is BMW just smarter than all of us, and 14.9-15v really is ok?

Everything I'm reading about AGM seems to suggest it's too high. But what do I know, I'm not even German. 🤷‍♂️
 

·
Registered
Joined
·
92 Posts
Rectangle Slope Font Parallel Screenshot

Presumably, charging the battery at 14.9V won't cause it to explode and go up in flames (I hope). To the extent that it's detrimental, does it just slowly degrade the battery?
I have a Bluetooth voltmeter, it’s only been fitted for about a week. The two rides I have done since it’s been fitted I get a reading of 14.8v. Now my bike is three years old and on the original battery, it still seems fine despite that high charge rate.. perhaps it is ok at that voltage..:)
 

·
Registered
Joined
·
582 Posts
Discussion Starter · #18 ·
I would so love to be wrong! It’s a new World out there toss the old standards.
 

·
Registered
Joined
·
503 Posts
I'm the other kind of story, where I had to swap battery (under warranty) well under one year from bike purchase.

I'm taking a wait and see attitude. But if the second battery fails early, I'll be looking for answers before I exit the safety of warranty and free battery swaps.
 

·
Registered
Joined
·
92 Posts
I'm the other kind of story, where I had to swap battery (under warranty) well under one year from bike purchase.

I'm taking a wait and see attitude. But if the second battery fails early, I'll be looking for answers before I exit the safety of warranty and free battery swaps.
Wonder if how long a journey makes a difference, I never do much more than an hour and half in one stint, so maybe that’s not enough time to cause the battery to overheat… possibly a lot of slow city riding with a hot engine and not much air cooling.. who knows 🤔
 
1 - 20 of 48 Posts
Top