Alternator/Rectifier/Charging problem 5th Gen

Yes this is another one of those questions about the rectifier. I replaced the rectifier on my 99' model say 500miles back and now again the battery has drained and it is not charging. I checked the battery voltage without bike running ist 12.2V thats fine, i start the bike and the voltage stays the same, then I run it at 5000rpm and it wil only go up to 12.5V max, and then when I switch on the lights it drops down to 11.8V with the bike at 5000rpm. So its draining the battery and there is no charge. I did check the alternator the resistance over each coil is plus minus 0.3ohms and non of the coils are down to earth. And battery was checked and in good condition.

So I am quite sure the r/r unit has packed up only after 5oomiles, I know the alternator should give you 0.47kW, so I measured the voltage per coil running at 5000rpm that gives me 60V, then I should take the current over the coils, not sure if I am doing that correct but getting say 0.36amps. If someone knows how to correctly check the alternator please let me know.

And is there anything alse that could be wrong or cause then bike not to charge? Otherwise I would have to replace the r/r and if there is anything else wrong I don't want to have to replace the r/r again.

Let me know what you think.
Thanks

 

Battery is too weak, can't take a charge.

Try charging your battery if it will, then measure the dc bus voltage again.

A normal battery at rest should be 12.8, yours is toast. The bus voltage dropped to 12.5 at 5k because it is trying to charge the weak battery and using so much current that it is pulling the bus down. Add the load of the lights and it gets pulled down even more.

60 volts AC out of your alternator says it is working fine. You would need a clamp-on current probe to measure the alternator current, and you could measure the dc bus current also.

The RR seems to be working because your 12.5 bus voltage was higher than the no-load battery voltage of 12.2.

Measure your battery voltage during cranking--if it drops below 10 it has no guts left and you need a new one.

 

Don't think i'd question K-B's analysis cuz the dude has serious depth of knowledge, but seems like a bad r/r or bad (melted, burned) wires is the nefarious culprit in this case.

Where the 'ell has this guy been and why did it take him so long to join up over here and what he thinks about VF500s is what i want to know. A high "Thanks" count is what i expect.

Of course it could also be a f'ed-up battery since the r/r is so new.

 

Sorry for taking so long to get back but was busy. Well I charged the battery and after charge I checked it was plus minus 12.8V, I have recently taken a trip with the lights on and everything and looks like there are now problems now, but have to check the battery voltage sometime again. The original fault of the battery going dead could be because the bike was standing for 3months and I only started the bike ones a week. And that was not enough to keep the battery charged. Will check the battery again and see if the RR unit is charging it.

Cheers

 

FYI, starting a bike and letting it run once a week/ once a month isn't going to keep your battery charged. It may keep your carbs from gumming up but in order to keep the battery charged you need to ride it for about 1hr or about 25 mi. The charging system has a break even point which on most VFR's is 4-5000rpm before it throws a charge to your battery. Then again you can just invest in a battery tender and stabilize your fuel.

 

Yes, it sounds like a battery tender would be the best, but the question then is when do I put the battery on that, meaning for how long must the bike stand for me to justify to put it on the tender. Say I sometimes I drive 3 to 4 times in a week and then a other week just once and then I don't drive it for a week again. To avoid having to put it on and of every time I want to take a ride?

 

Goo day,

So I chraged the battery the other day and put it back in the bike. When I measured it it showed round about 12.96V. Then I started the bike and while ideling at plus minus 1200rpm the reading was 13.2V. Then when I let it run at 5000rpm the reading whent up to 16V and when I put on the lights it dropps to 12.6V and then when I put it on brights it drops down to 12.1V. So what could be the problem? Because as I undeerstand the Volts should not be going as high as 16V?

Let me know if someone knows?
Thanks

 

Eek 16v that's is strange how does you stator plug look? If burnt they need to be placed have you measured the amps coming out of the R/R?

 

Good Battery, but regulator/rectifier is questionable

Sounds like the battery has taken a good charge, and the 13.2 at idle was a good sign, but the 16V indicates that the internal control circuit of the regulator is out of spec since it should not go above 14.4.

When you turned on the lights, was that at idle or at 5K rpm? If at 5K then definitely a problem, if at idle then maybe okay.

But electronics don't heal themselves, so if the regulation circuit is gone then you will have to replace it.

What is the wattage of your lights--have you added extra lights to your system? How come you lights are not on all the time whenever the ignition is on? Sounds like some custom mods going on here that could invalidate the usual assumptions...

 

So what happened to this whole issue was, I was driving the one day and then I just lost all power to the bike. After getting it back to home decided to take to electrician, he investigated and the feedback I got was, that the guy that installed my regulator installed it incorrectly because he did not connect the wire that stops it from overcharging. So the it was overcharging and because of that the connectors got fried and the wire inside of the regulator also fried. So what he did was to replace the wire inside the regulator and then also remove the connectors and rather fuse the wires together. And also installed a fan on the regulator to keep it cool. After that I have not had any problems and the bike runs like a dream.

Thanks for all the advice guys

 

Humm, sounds like custom mods alright.....sense wire delete (shakes head at the thought)

Ok now that your R/R has ben cooked once, start looking for a replacement as it is now only a matter of time before you wil need it. As I seen above, electronics once bruised dont heal. That said the next problem you have with power may not be the R/R, but I would put money on it that the next time will be the last that R/R sees active duty.

 

When my R/R died (fortunately, it only fried three headlight globes, then went to zero volts), I bought a high output MosFET unit from a R1 (there's a thread on this site somewhere showing how someone else did it). I did a thorough job of the soldering, and made sure I didn't get the wires too hot too close to the R/R. I've done thousands of km's since then, and it has never been a problem again.

Moral of the story: If in doubt, whack in the R1 reg!