Flat battery - why?

[posplayr]

OK so a recap,
Fresh battery
System passes charging test at 2000 and 5000 RPM(13.2v and 14.4v)
battery goes flat after how long of riding?
Does it go flat just sitting there off?

There seems to be a contradiction. I suggest putting a volt meter on the battery while on the bike and ridding it. It can't discharge (unless the battery is defective and has a excessive internal self discharge) is you have over 13.0 volts on the battery ridding.

When You say flat I'm assuming the voltage has dropped to 10V or less and it is not the fact that the starter doesnt crank. many things could have the starter not crank and not be the battery.

[psyguy]

OK so a recap,
Fresh battery
System passes charging test at 2000 and 5000 RPM(13.2v and 14.4v)
battery goes flat after how long of riding?
Does it go flat just sitting there off?

When You say flat I'm assuming the voltage has dropped to 10V or less and it is not the fact that the starter doesnt crank. many things could have the starter not crank and not be the battery

last sunday i went for a few hours ride with multiple stops. i started fine on the one-before last stop. then half an hour later when i stoped again, it wouldn't start - it IS the battery (not the starter) as the headlight was dim, but the bike started no prob when jump-started by a car battery.

i don't know if the battery would go flat by just sitting as i have it on the battery-minder. but it holds charge overninght even when not on the charger (tried it for one night only). the battery is new.

There seems to be a contradiction. I suggest putting a volt meter on the battery while on the bike and ridding it. It can't discharge (unless the battery is defective and has a excessive internal self discharge) is you have over 13.0 volts on the battery ridding.

yeah, i know, it's crazy...

i dont have a vom that i could connect and monitor while riding but i know some people here have a small vom that they put on the handlebars.

does anyone have a link to that product?

[chef1366]

http://www.kuryakyn.com/index.cfm/go/Home.Default/prodFam/Metric

[posplayr]

any cheapy meter will work with some duct tape, but this would be nicer

http://www.casporttouring.com/store/...&Category_Code=

[psyguy]

any cheapy meter will work with some duct tape, but this would be nicer

i'm not a big fan of too many extras on the bike, so may try the duct tape first

[posplayr]

One other thing I would check, since you do not have a clamp on current meter (I'm assuming) you can use your vom and the parasitic resistance of your harness to confirm the system is pushing current to the battery.

The R/R (+) output should always be higher voltage than the (+) battery at anything above 2000 RPM. If it is not then the battery is discharging. This will be something in the range of 0.25V to 0.5V or as high as 0.75V with poor connections at 5000 RPM. Confirm your meter indicates negative voltages when you reverse the leads. Negative means discharge when measuring Red to R/R (+) and Black to (+) battery.

This may be a better indication of what is going on. Something is apparently changing while you are ridding. Could be a thermally induced break in your stator cause it to stop outputting when it gets hot. Could also be a temp sensitivity of the R/R I guess.

If the voltage does anything wacky during riding you will likely have to dive in to charging. I'll stop guessing now.

[LHO39]

Voltmeter

I used electrical tape to fasten my round 2 inch troubleshooting voltmeter to my handlebars. Incidentally there is a very handy place to connect to 12 volts. Most bikes have ignition voltage to one side of the horn and the horn button then grounds the other side. Find out which of the connectors is 12 volts. You can just slide a bare wire into the spade connector. Quick and dirty is sometimes best.

[chef1366]

Alligator clips are for more than smoking roaches.

[seuadr]

this may or may not be helpful, but i had a similar problem last year. it turned out actually to be my starter clutch. i know how stupid that sounds, but bear with me.

the bike wouldn't start, at times, after riding for a while. one of the magnet cups the magnet broke off of, and the puck that caught the shaft when the starter was engaged to turn the motor off could move around freely. sometimes, when i stopped, it was at the top, and seemed to drop down into the clutch area and jam it. so the starter wouldn't even work. just a click. all the lights were fine, fuses good, battery voltage checked out fine. confused the hell out of me for weeks. I'd get ****ed, walk away from the bike for a few mins, and then come back, hop on, roll it off the center stand, and it'd start fine, because the puck would make it's way back into the proper area.

so, i guess my question is. when you got it jumped by the car, did you roll it before you tried it?

sorry for the long story, just wanted you to know where i was comming from.

[posplayr]

this may or may not be helpful, but i had a similar problem last year. it turned out actually to be my starter clutch. i know how stupid that sounds, but bear with me.

the bike wouldn't start, at times, after riding for a while. one of the magnet cups the magnet broke off of, and the puck that caught the shaft when the starter was engaged to turn the motor off could move around freely. sometimes, when i stopped, it was at the top, and seemed to drop down into the clutch area and jam it. so the starter wouldn't even work. just a click. all the lights were fine, fuses good, battery voltage checked out fine. confused the hell out of me for weeks. I'd get ****ed, walk away from the bike for a few mins, and then come back, hop on, roll it off the center stand, and it'd start fine, because the puck would make it's way back into the proper area.

so, i guess my question is. when you got it jumped by the car, did you roll it before you tried it?

sorry for the long story, just wanted you to know where i was comming from.

I hope we are not guaging the battery health by how well the motor starts . Too much to go wrong to use that as a battery test; apparently the battery is going flat Right PsyGuy????

[seuadr]

I hope we are not guaging the battery health by how well the motor starts . Too much to go wrong to use that as a battery test; apparently the battery is going flat Right PsyGuy????

not so much gauging the health of the battery as having a perfectly good battery that sometimes won't work. i'm just sharing my story incase it may ring true for this situation. i skimmed through the thread, but i admit i didn't read all of it. i didn't notice anything regarding the battery being tested as dead, but rather just acting like it's dead, which is what mine was doing at the time as well. if i missed him saying the battery was verified as totally dead, i am sorry. not trying to add any confusion.

[posplayr]

not so much gauging the health of the battery as having a perfectly good battery that sometimes won't work. i'm just sharing my story incase it may ring true for this situation. i skimmed through the thread, but i admit i didn't read all of it. i didn't notice anything regarding the battery being tested as dead, but rather just acting like it's dead, which is what mine was doing at the time as well. if i missed him saying the battery was verified as totally dead, i am sorry. not trying to add any confusion.

Well I'm not sure he verifed the voltage either, he simply said the lights dimmed. That would happen if there was a mechanical block and the starter sucked a bunch of current and pulled the voltage down. Seuader, it is interesting this can occur and appear to be a dead battery ; I'm hoping PsyGuy was not fooled by this situation and he really has a flat battery. Else wise I'm chasing my tail.

Probably the simplest test that will give you a good indication of battery state is to measure the voltage at 12.8V with bike OFF and then turn ON the ignition (so the coils are energized) and see how far that pulls the battery down (simple load test) ; should be about 12.5V. This is a health battery and relatively controlled test.

If that doesn't work, you either have bad coils or bad battery.

[psyguy]

thanks guys.
the battery was definitely flat as the headlight was dim with just the ignition ON (no cranking). i did not confirm the actual voltage but the bike started right up with the jumper cables, without moving the bike at all.

Something is apparently changing while you are ridding. Could be a thermally induced break in your stator cause it to stop outputting when it gets hot. Could also be a temp sensitivity of the R/R I guess.

this is an interesting idea. i think the problem may be happening on an on/off basis - i've ridden numerous times with no problems whatsoever, but the battery did go flat on two ocassions - while the ride circumstances stayed all the same (time, mileage, temperature, etc,).

having a vom connected while riding to see if there are any anomalies seems like the most sensible thing to do.

i'll report back when i have some data.

thanks everyone


ps. i'll go get some aligator clips for my vom, sounds like a handy little thingy

[seuadr]

thanks guys.
the battery was definitely flat as the headlight was dim with just the ignition ON (no cranking). i did not confirm the actual voltage but the bike started right up with the jumper cables, without moving the bike at all.



this is an interesting idea. i think the problem may be happening on an on/off basis - i've ridden numerous times with no problems whatsoever, but the battery did go flat on two ocassions - while the ride circumstances stayed all the same (time, mileage, temperature, etc,).

having a vom connected while riding to see if there are any anomalies seems like the most sensible thing to do.

i'll report back when i have some data.

thanks everyone


ps. i'll go get some aligator clips for my vom, sounds like a handy little thingy

oh hell yes they are. sometimes you need more than two hands, a couple clips on the ends of your leads and you are business!

[psyguy]

I suggest putting a volt meter on the battery while on the bike and ridding it. It can't discharge is you have over 13.0 volts on the battery ridding.

so, bought some aligator clips for my VOM, put them accros the batt + and - , and went riding today - voltage tested at a steady 5000 rpm:

• new battery
• 13.1V fresh off the charger and holds charge
• while riding with the HEADLIGHT OFF - charging at 14.7V
• with the HEADLIGHT ON, the voltage immediately dropped to 13.7V and then slowly kept dropping to 12.2V (it took an hour to drop this far)
• after turning the HEADLIGHT OFF AGAIN - charging at 13.1V and slowly goin up (after another hour or so) to 14.6V