12.6 volts at ilde

can anyone tell me what voltage i should be getting at idle?
I've left my 2002 vfr running last weekend with the lights on but it has cut out when the coolant fans cut in when i went to restart it i found the battery was flat!
i have charged the battery check the charge and found 12.6 volts at idle but goes up to 14.6volts at 5000rpm
can anyone tell me if this is correct

 

14.6 at 5000 rpm is a good number, you got other issues though if your bike cut out when the fans came on. Invest in a new battery if its old.

 

thanks for the reply i'm going to see about a gel battery i've heard they are a better battery

 

Talk about coincidence - I was just going to start a thread on voltage readings. So Stevemull, I'm going to hijack or piggyback your thread.

On my 5th Generation:

Replace the battery November 2011. It wouldn't hold a charge for longer than a day. I.E. Charge battery for 24 hours. Unplug for 24 hours. Check battery - no go. So I replaced it. It was about 3 years old, but I had never kept the trickle charger on it. Shame on me for neglecting my battery.

So, new battery. New trickle charger. Take it off the charger today. Here's my readings:

Bike off: 12.75

Bike at idle (after 2 minute warm up): 12.25 constant

Bike at 2000rpm: 14.5 constant

Bike at 5000rpm: Holds at 14.5 for about 2 or 3 seconds, then drops to 12.25. I tried this repeatedly, and got the same results over and over.

So what gives? I know my R/R has been upgraded in the past (before I bought the bike).

Mom was right - I should have paid attention to all those other R/R and stator threads.

Anyone got any thoughts on why my reading holds then drops at 5000?

 

The voltage at 500 rpm would drop if there is no load and it is not needed. Then the excess is given off as heat. that is why it has the finned aluminum heat sink.

Try this... turn the lights on at 5000 rpm and watch what happens.

 

Thanks Donald. I understand. (I'm assuming you meant to say "...voltage at 5000 rpm..." and not 500).

My bike is a 2000, so the lights (low beams) are always on.

But anyway, as I dug deeper into this, I found some fried wires. I didn't suspect this because my R/R had been previously replaced and I only have 15,000 miles on the bike. But as my Italian friend says "izza no-goood".

Will post pics of the culprit later.

 

Hi, Pliskin, what a coincidence. It seems my RR is finally giving up lately. I still have the infamous original RR (SH579A-11)!!! When I started up my VFR after long winter sleep last weekend, bike hiccupped. It started finally but I noticed my trip counter on the gage cluster reset to zero. I rode the bike anyway. After riding about 40 miles, I came to a stop and took some rest. When I started the bike again, no click. WTH. I waited a little bit and restarted. It worked but reset the trip counter to zero again. I rode the bike home without stopping afterwards and checked the battery connections and grounding wires. I measured the battery voltage (13V). All looked fine then.

I checked the voltage again today. The battery reading was about 12.5V without engine running (bike was cold). At idle, reading was 14.2V. At 5,000rpm, the voltage dropped to 13.5V. After few minutes, the voltage began going south. Even at 5,000rpm, I was reading 12.0V and somewhat lower. RR is very hot to touch. Is this the typical symptom at the end of its life?

 

Hey IRvfr! Hope you've been well. Looking forward to riding again soon.

I'm no pro with this, but what you're describing is exactly what took place with my bike. Specifically, holding better voltage at the lower RPMs, and then watching it decline as it got higher.

I finally inspected the bike some more today, and sure enough, my wires are fried. Here's some pictures (terrible ones, and huge) that I posted on the other thread. Click below.

http://vfrworld.com/forums/mechanics-garage/37595-melted-stator-wires.html#post348254

I obviously have problems based on this, so I'm going to change the R/R as well as install the VFRness. Good luck, but I wouldn't take any chances! lol

 

Idling for any more than about 5 minutes is something that should always be avoided as it leads to flat batterys and overheating !!~

Depending upon conditions, the bike needs to be MOVING after about 5 minutes to handle the building heat. The fan does not always keep things cool enuff.

 

Squirrelman, I hear you. I shouldn't idle for a prolonged time. Glad that I caught this problem at my garage not at a remote roadside.

Pliskin, I saw your pics. They are tell tale signs you had a good time with your bike :music: It's scary though. I think I need to check my wire connections too. I googled the VFR RR issues today. It seems this problem can resurface even though you replaced the original RR. I saw one posting at this site that he replaced RR several times for his 5th gen. I wonder whether he used the upgraded RR model.

 

Idling for any more than about 5 minutes is something that should always be avoided as it leads to flat batterys and overheating !!~

was looking for the quote thing unsuccessfuly, anywho-Squirrel try balancing those v-four carburetors in under 5 minutes! Sheesh, I think I had a fan running while working with one of my 4 specific carb tools and a mechanics mirror. Went to the dentist that week and mentioned working with a mirror and how I was cursing, he said, "its not easy is it, I do it every day." dentists are weird0s

 

Thanks for catching that typo.
Also about batteries.

A 12V battery when fully charged should be more that 12.6 volts.
Here is why.
Each cell should be 2.3-2.7 volts so if you multiply that times 6 you will get
about 13.8 volts at rest. 12.6V is ok but if the battery is 5 years old I would replace it.

 

I had this same issue with my VF1000R chopper.
All new connections but the plastic plug -ins were old and deteriated.
Anyway I found a lot of corrosion within 2-3 months.

I have worked on motorcycles for many years and have never seen this
type of problem with these regulators and the rapid corrosion.
It is something wrong with the basic electrical design.
I have been working on a 33 year old Honda CB750 and it and others never had these
types of problems.
Matter of fact many of the old CB750's have the original
old fashioned electrics, and still work to this very day.

Honda needs to get motorcycle people back into the design dept.
Also it would not hurt for the young engineers to take a look at their
own early designs and find out why they worked so well and still work 30 years later.

 

Many mechanical and electrical problems are found with a good visual inspection.
So even if you have limited skills you can find many problems and correct them.