blackbird11xx

I have been through all the threads on the charging system, the R/R & Stador failure etc. But I can't find anything like this one....

Most of the time and for most of my riding everything is great. Bike starts first touch of the button. However while riding in traffic, if the bike starts to get hot (215F+ the fan turns on) after about 10 mins the headlight starts to fade at idle. If I stop the bike at this point it will not start the bat' is all but dead. Hitting the starter button with will do nothing but blink the idiot lights and reset the trip and clock.

So I put on a voltmeter while running everything is normal (based on others posts on voltages) but once the bike gets hot and the fan comes on at idle the voltage drops to around 11.1 volts. Now here is the really odd part, the hotter the bike gets the lower the voltage drops, all the way down to the point when the meter stops showing the voltage. Once I start moving and the bike starts to cool the voltage starts to come back up.

Anyone got any ideas its only a problem if I get stuck in traffic. (I can and have bump started the bike several times and it fires everytime first time)

Thanks

shewie

How old is your battery? If it is aging, feeding the fan for extended periods can be more than it is capable of if you are not running at high enough RPM to keep the alternator operating.

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If you don't like the way I ride then stay off the sidewalk.

billypf

What RPM does your bike idle at?

blackbird11xx

The bike is an 02, and it idles right around 1100 rpm.
The bat' is about 1 year old and is plugged into an tender when not being ridden (the original bat' lasted about 1 year, bought the tender and the 2nd bat' lasted almost 5 yrs)

Also took the Bat' local bike shop and they put it on the tester and it tested out ok

shewie

Have you changed your riding habits lately? Are you spending more time in traffic snarls than you used to?

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If you don't like the way I ride then stay off the sidewalk.

RazinKane

My bike acted the same before the R/R went out. You my want to get the bike hot and unplug the R/R and check the AC Voltage you stator is puting out. I found out that a failing stator can work fine while cool, but when hot it will fail...

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We occasionally stumble over the truth but most of us pick ourselves up and hurry off as if nothing had happened.

ravi

Have had the same problem in the past. and down here in India, traffic is a lot worse thereby further accentuating the problem. not sure if there is a solution to this but one thing that did help quite a bit was to install a euro headlight switch so that the headlight could be cut off in very slow moving traffic and more so when the bike was at a standstill. That prevents the battery from getting drained and also helps push more power to the radiator cooling fan. A flushing of the radiator and adding some water wetter may help a little. But all in all, i don't think there is a permanent fix to this problem.

Do keep us posted in case the r/r solution that RazinKane suggests works... will try it myself in that case. Good luck. Ravi

Poundstretcher

the battery doesn't get charged when on idle revs. It would appear to me that it is not a heat issue just that it is at low revs when hot ie no charge & higher revs when cool ie charge. Check out the R/R thread in the resource centre.

JohnS

It's possible that one of the bridge straps inside the battery is cracked and heating is causing expansion of the bridge and open circuiting the battery.

I would check by removing the battery and carefully heat it with a hair dryer while connected to a volt meter.

This is a long shot but what you described is not giving me enough info to come up with anything else.

PS Don't get it too hot and no sources of ignition.

JohnS

uis048

Mine has now started doing the same. Really hot day, caught in a motorway tailback of 15 miles, finally got clear and had a 'normal' ride home. Left it outside whilst getting out of gear / opening garage, went to start, only got a slow crank of the starter.
In mind of all the posts, I immediately checked battery voltage (Brand new battery, less than three weeks old, good quality unit):- 12.3V.......

Jumped it with a starter unit, fired straight up. Measured voltages, after 1200 RPM right up at 13.8V.

Put battery on charge for an hour, battery holding volts, no drain apparent. Started up right on the button, plenty volts from alternator/ rectifier.

The bike was searing hot when I got home, I had been riding with lights on and, obviously, the fan had been a-blowin most of the time.

I have to suspect the alternator, but will keep my eye on the reg/rec as well. If anything proves faulty I'll re-post.

(98 carbed with original reg/rec. Does have alarm/imob fitted, but I am pretty anal about battery condition and charge both bikes on a weekly basis)

Forgot to say, 16,500 miles.

blackbird11xx

OK I finally have an answer for what was causing my problems.

After doing all the tests I could find including taking the Bat' to 2 places to get it tested (both of which said it was ok). The problem was the Bat'.

It appears to be a dead cell within the Bat'. How did we determine this?

I took the Bat' (fully charged) and checked the voltage 12.7

Placed a load (about 10 amps) on the Bat' checked voltage 12.1

After about 5 mins checked voltage 12.1

After about 10 mins checked voltage 10.8 !!!!!!!

After about 15 mins checked voltage - unstable, unable to get an accurate reading

Stopped test.

Recharged the Bat' checked voltage 12.7

So what was going on.... well it would appear that with the bike idling and getting hot, the fan would come on, this would draw more than the charging system can produce. For a few minutes this would be ok, but then the voltage would start dropping (and yes the fan starts to go slower) bike would get hotter because the fan can't keep up with the heat. Eventually (5 mins at idle..) one very hot bike with an almost dead Bat'. If you turn the bike off it will not start, but once cool, bump start and run for a while, Bat' charged and it will start everytime, plus all your voltages read right about where they are supposed to be.

I switched the Bat' and the problem is gone.

Just to make sure I was not going crazy I put the old Bat' back in and let the bike idle getting hot, about 5 mins after the fan first kicked in... bike is way hot and Bat' is dead. So I think I have this solved.

shewie

I'll direct your attention to post #2.

__________________
If you don't like the way I ride then stay off the sidewalk.

Poundstretcher

Another problem solved and a bit more useful info to store