zenrider

Hi all,

I recently bought a 1998 superhawk and thought I had fixed the slowly dying battery problem. It appears I have been out smarted! I'm seeking suggestions about what to check next in my charging system. Here is whats been happening:

Since I got the bike a few weeks ago, the battery has been going dead. The guy I bought it from said the battery was new within a few months of when I bought the bike. But the batter didn't have enough juice to start the engine. After charging the battery overnight with a trickle charger, the battery works fine for several days. It seems to be depleted by about 20 times starting the engine. However, once the engine is started with jumper cables, the bike runs great with plenty of power and all electrical components work fine. I assumed that the bike wasn't charging the battery but was producing enough power when running to keep running.

I used a voltmeter and determined that the voltage across the terminals never went above 12.4v even up to 7000 rpm. It dropped to about 12.1 at idle. My diagnosis was that the regulator was "over-regulating" and preventing the battery from being charged. So I got a new, stock regulator, installed it and rechecked; now the voltage maxes out at 13.7v at 5000 rpm. According to my shop manual, the acceptable range is 13.5v to 15.5v at 5000 rpm. So although 13.7 seemed low to me, its in the okay range. I though it was fixed and done.

However, this morning on my way to work, I stopped for gas, and the bike wouldn't start! It "tried", but didn't have enough juice to turn the motor. I got a jump start and made it to work. But I'll have to get a jump after work to get home.

And then what?

Of course I'll have to check the voltage again, but it seems unlikely that another regulator went bad in a week. If it IS bad, what would cause the bike to burnout another one so soon? Any other suggestions? Is 13.7v really an okay charging voltage? Could I have a current leak where the battery is slowly being drained? How would I check for that? Has anyone seen this symptom before and found a solution.

Thanks!

hawxter996

check main ground could be corroded.
after that id question battery condition.

zenrider

hawxter,

What do you mean by "main ground"? Do you mean the negative terminal on the battery or the other end of cable that connects to the negative battery terminal, or something else?

Thanks,

zenrider

hawxter996

there is a ground that is attached to the frame
or subframe,dont remember exactly where.
but if neglected could cause problems similar
to what your having.

RickB

An easy way to check for a drain is to remove the + battery cable and put a 12v light bulb or test light (incandescent bulb type preferred, not an LED test light as they are much more sensitive and may give a false reading for clock/odometer draw) inline between the battery and the cable. if it lights you have a drain somewhere and you can try pulling fuses to eliminate those circuits in the troubleshooting process.

Was the new regulator the old non finned style? the later ones like my '02 have the finned type for better heat dissipation and seem to hold up a lot better.

trinc

every time you run down the battery it looses some of it's capacity, could be that the R/R was the original problem but the battery is probably spent.

have it load tested of buy a new one.

tim

a good read:
http://www.yuasabatteries.com/motor_battery.asp

zenrider

Tim, thanks for the link. That was an insightful read!

I guess I will head over to the local "Battery Plus" store and see if they can evaluate the condition of the battery.

I also went down to the parkinglot and checked hawxter's suggestion about the ground wire. It attaches below the rear CCT and looks very clean. I don't have tools with me to remove and check, but I'll give it a thorough cleaning tonight. I'll also re-check charging voltage and look for signs of over-heating within the charging wiring and connectors.

RickB, I got the old, no-finned regulator. If I need another, I'll look for the more robust version with fins.

Thanks

swordfish

in the beginning of the season my bike had the exact same symptoms. it was a bad r/r. the finned version fixed it.

derryuk

Zenrider,
13.7V isn't enough to fully charge your battery. You need around 14.5V to do that.

It looks like your replacement RR is bad.

Derry.

Aaron_D

If you go to the Electrosport website, there's a really good flow chart for diagnosing charging system problems. Download it, print it and take it out to your bike with a multimeter. You'll be able to tell whether it's a R/R, stator, bad ground, etc.

doggerman

ive been through this.Check out the free manual in the Forums"knowledge base"its a little easier to understand.The testing process is simpler than electrosports.Could be the stator or the R/R.I bought both from electrosport.

gboezio

Check your stator health, take a multimeter and test the 3 stator wires, it should be between 0.2 and 0.5 ohms between each other.

zenrider

Hi again and thanks for the new suggestions. I checked a few more things in the garage this morning. I followed the online shop manual. Here is what I learned....

First, the three stator wires are all the same when checking resistance between them; all three combinations yielded 0.6 ohm. This seems slightly higher than what "gboezio" says it should read. Is 0.6 ohm still in the okay range?

Second, when I connect the stator output wires to the negative battery terminal, they also all yield 0.6 ohm. Shouldn't that read infinite? The manual says there should be "no connectivity to ground"? Am I checking that correctly?

Third, checking voltage when the engine is running again is yielding about the same voltage; about 12.2 at idle and slowly increases with rpm until a maximum of 13.7v at 5000rpm. The manual says that the correct range is 13.5v to 15.5v but the link to the yuasa battery explanation (provided by "trinc" above) says 13.5v is okay to maintain charge a healthy battery, but not help resuscitate one that is at low charge.

I should also note that the battery started it right up this morning with no trouble. (!) My next step is to carefully check for corrosion and faulty connections.

Can anyone add any interpretation what I've reported?

I sincerely appreciate eveyone's assistance.

Thanks!

doggerman

The simple test for the stator...Proved true for me....."check for ground on all three wires coming from stator at three prong connector =3P" thats the first connection at the base of the tank.If its got a new r/r its gotta be the stator.Your voltage at the battery is to low

gboezio

The resistance you got looks good, you are checking for an open circuit, the fact that they allr ead the same is good news, I don't have access to my manual due to peice of **** computer (on GF cpu now), but stator to ground low impedance raise a ?

derryuk

Zenrider, check the charging voltage with the lights switched on. If it falls below 13.5v then you could be discharging the battery.

Derry.