Odd battery drain when off

Hey all,

Long time lurker, first time poster. Having trouble with my '97 VFR's charging system. Have read a ton of posts on the topic but have found nothing that is quite the same.

Bike almost always starts / charges just fine. Sometimes however, it will start up, ride great until I park it. When I come back 2-3 hours later the battery will be dead. I replaced the battery about a month ago because it was old, and I suspected it may be the culprit (it tested okay, but it was about 4 seasons old and I thought it was time). It seems like it happens more on warmer days which leads me to believe it could be the RR, but, the bike never dies while en route, only after being parked for a few hours. I've started suspecting that maybe the radiator fan is the culprit, perhaps staying on too long after the bike has been parked.

Would love some feedback. Frankly electrical issues are new to me so anything helps.

Thanks,

CJ

 

Hi and Welcome to the MadHouse:welcome:

When you get a chance swing by the "introductions" sub-forum and say a proper hello to the rest of the folks on here and post up at least one photo of your bike or it won't be long before people start raggin on you! You may also want to update your forum profile ("My Profile" link at the top of the page) to include your bike specs and a rough location (city/state) so the information appears with all your posts and you won't end up having to repeat it.

:focus:

Hmm sounds like you need to do "the drill" to work out what is going wrong and what components may need replacement - see post #9 in this link - http://vfrworld.com/forums/showthread.php/39277-How-to-fix-common-regulator-Stator-failures

Basically all 4 elements of your charging system (battery, RR, stator and loom) need to be in good order, and a fault in one can damage some or all of the others. I think the mention of warm weather suggests it may be the insulation of the windings in your stator is starting to fail. Mine went after a long hard ride in really hot weather, but weirdly the stator output tested fine when the bike was cold - only when the bike warmed up did the insulation fail inside the stator and instead of charging the bike, it settled down to discharge the battery. However without doing the drill you could be throwing money at replacing the wrong components as it could just as easily be down to dodgy wiring or melted connectors which your version VFR is known to suffer from. The thread linked above, shows the most common culprits, but to start with, pull the fairings to check for crispy wires and then get busy with a multi-meter.

If you are not sure about the results just post the numbers up here, and we will try and help you understand what they mean.

Good luck let us know how you get on.


SkiMad

 

Skimad4x4 - First of all, I added myself to the introductions page - thanks good suggestion.

Second, I ran through "the drill" voltage looked fine at idle about 12s at idle. Went up to 13s at 1900; low 14s at 5k.

Taking your advice, I went on a spirited ride and got the bike hot. It tested 12.3@ 5k; highest I could get it. Does this sound like an RR?

I'm going to let it cool down before I run through the other tests, I'd like to isolate the problem w/ heat.

 

Howdy and welcome aboard.

12.3 at 5k is definitely too low, so something is amiss.

 

With those results I suspect the RR may indeed be the problem with your bike. Remember the RR can't create extra volts it only rectifies AC to DC and then is meant to keep the output within defined parameters. The fact that at one stage the volts were over 14 confirms that at that stage the stator was producing more than enough volts to put the charging system into the normal battery charging range. However before spending out a heap of cash on an RR, I would arrange one more test to definitely eliminate the stator as being faulty.

Basically your bike can run OK for a while (a few minutes) without the stator being actually connected to the RR (effectively using the battery to keep the bike running). So what I would have done is once the bike was hot and that faulty charging condition became evident (ie when you saw the volts had dropped down to the 12.3 level). I would have turned the bike off and as soon as possible unplugged the stator/RR connector and then re-started the bike, and carefully tested the AC volts across all three pairings of the yellow wires coming from the stator, just to check the stator was still producing acceptable AC output. (and by implication confirming the RR as the problem).

You need to be getting decent and reasonably similar volts AC across all three pairings of the yellow wires from the stator (as I said the checks should be done with the stator/RR connector disconnected) at tick-over (ideally 20+ volts AC) and 5000 rpm (heading for 50-60 volts AC). If any pairing is way low or nil then the stator is duff. NB When testing, take great care with the test probes - you do not want to ground any of the yellow wires or indeed allow the probe to accidentally cross connect them or you will be seeing expensive sparks! If those tests come back OK then it looks like your RR is toast. In which case I suggest you go here for a reliable replacement. http://www.roadstercycle.com/





SkiMad





What voltage was the battery reading before you turned the bike on?

 

SkiMad,

Tested the stator per your recommendation. It is testing fine. Ordered a RR will let you know how it works out. Thanks for your help! The battery was reading about 12.5 (12-12.9) before the bike was on.

Thanks,

CJ

 

Mello,

Stator/rr connector looks fine. I ran it again while hot and found passing results on the stator. I am a little worried however, it was in the evening and it had cooled off appreciably. In retrospect it was really hot on the day it failed. Hopefully the ambient temperature doesn't affect it too much. Looks like it will be hitting 100's over the next week; I will double check during the day again.

Thanks,

CJ

 

Does the radiator fan spin freely by hand? A locked up fan motor can draw lots of current.

A good battery will be above 12.7 unloaded at rest. If the battery is shorted internally or bad it can pull down the charging system. If it is getting pulled down to 12.0 with just the key turned to 'on' then it is too weak and may be the source of the problem.

A good test would be to measure the current flow in and out of the battery. If you have a current draw when the bike is off then you need to trace it out to find the culprit. Ammeter or current probe, clamp-on or in-line.

 

Alright guys,

Had a chance to install the new RR and test it out. When cold, with the new RR it was at a constant 14.5 at idle and at 5k - didn't change much. Ran the bike, got it hot, tested again: Found it was 12.92 at idle and 13.45 at 5k. It still seems that these readings are a bit low. Would like to hear your thoughts. I will say it was very hot its about 105 F today (41C); as such, the radiator fan was going during these tests, not sure if that affects anything. With all else being the same 13.45k at 5k should keep the battery alive and well right? Kennybobby; the battery is fine; newer and tested at a local shop. I don't remember the exact number but it tested above 12.7 when I tested it last week.

Thanks for all your help!

CJ

 

Quick update:

Let the bike sit for about 10 minutes; long enough for the fan to not kick on (still very hot). It tested 13.2 at idle; 14.2 at 5k. My thoughts are that these are favorable results. Let me know what you guys think.

Thanks,

CJ

 

Bike has 42k. I was under the impression that my readings were now okay. It tested 13.2 at idle; 14.2 at 5k with the fan cycled off. 13.45 at 5k with the fan cycled on. Seems reasonable for the fan to draw some.

I guess, what does it have to be at 5k minimum to charge the battery? I can't fathom it ever getting hotter then it was today. It is 105 degrees ambient and I drove it hard. Usually the fan cycles on when I slow down; not sure if runs much at highway speed.

Battery load tested fine.

 

Gotcha - that makes perfect sense. Unfortunately I don't have a voltmeter installed on my bike like the one pictured. That is really cool btw. However, I'll keep an eye on it - just throw a voltmeter in my backpack and check it from time to time.

Thanks for all your help!

 

Ok, I'm having the same issues on my 5th Gen. 2nd battery in 2 months. When you guys call "stator", is it the same as the alternator? Like car ones? Cars have them outside, with a belt attached to it to work and charge properly, giving it's functions like I know it. On motorcicles, it's internal, right? On one side of the engine (depending on the bike, but usually the same).

But the language barrier makes me think if what you call stator, is what I call alternator (keeping a electrical circuit and charging battery).

 

For this conversation - yes, its the same thing.

 

My readings

Just battery alone in bike: 12,51 (jjst 2 hours charge yestwrday night, started once, no problms, rested for the night, started in the morning, no problems again, and now no problems again for the tests)
Idle - 14,10
Rev 2 and 5 rpm- 13,90
Same rev with lights on - 13,50

All these were cold starts.

 

At 12.51 with no ignition, you are at the lower end of acceptable. The battery should really be at a minimum of 12.6 with nothing on, and maybe as much as 13.2. (There are 6 cells on these batteries, and each cell is designed to hold 2.1 to 2.2v. So that's where the 12.6 to 13.2 figure comes from).

The fact that your voltage decreases when you increase your RPMs hints that your R/R is not doing its job either.

Have you checked all connectors and wires to make sure there is nothing burning up? Sometimes problems can be hidden behind the spade/lug connectors that snap together.

 

I would check them up, but the guy at the shop tightened the bolts way too much, and I can´t unscrew it without making crap...

I will go there tomorrow, I facebooked him, with these results, and he say's it's ok. The battery, he is going to test it, if there is any kind of fault, since he have the brand itself for sale for a very recent period (Bronco... never heard of it.... I always used to have Yuasa)

But, tonight, going to make a few trips to heat it up, and check up on the results again warmer right after stopping