Regulator concern, am I overcharging Yuasa AGM YTX20HL-BS

My KZ1000 vintage superbike replica / cafe racer is nearly done except for seat padding and upholstery which should be done in 2 days. But before I took my fiberglass tail in to be upholstered, i threw a black bath towel on it for a seat and got in four short 15 mile rides through my favorite local twisties.

She runs great, and pulls like a banshee at high RPMS. I changed out my 15w-40 Rotella T dino oil classic blend and K&N filter (not the triple protecton on shelves now which admittedly is probably just as good) with another gallon of the same at the 30 mile mark to get the shavings out, on Saturday night.

Sunday I took it twice more up the 15 mile loop and brought her home to cool of in between each pass. After the second pass Sunday I decided I was done, and pulled the tail off to get it in my Jeep so it would be ready to take to the upholstery shop the next morning. Here is where this post gets electrical.

I noticed the slightest bit of moisture at the corner of the fill cap strip on my YTX20HL-BS AGM battery, and the battery was a bit warm even an hour after the ride. The battery lays on it's back with the terminals up and a local dealership said that technically only the YTZ factory sealed batteries should be run inverted - but I'm not inverted I told him - and he relented that a YTX properly activated and sealed up should be ok on it's side, just as I have.

He guessed that the charging rate might be too high but he also said that it might just vent a little on it's first few runs and then stop which is what i'm hoping for. So I decided to check the battery voltages while running and fired her back up.

I get anywhere from 14-15.5 volts at high idle at 2000-2500rpm. Then at 4000rpm I get around 14-14.5 volts, nothing higher. The regulator gets warm but not hot. This is with a complete from scratch wiring harness, Dyna-S / 3ohm coils, and all lights shut off. I'm sure the parasitic draw on my harness is much lower than stock, as I have ditched stock everything electrical except blinker, starter solenoid, and reg/rec. Stock gauges are gone, using an Acewell, blinkers are gone for Drag Specialties Eagle Eyes, etc, running two relays, one for the ATC fuse box and one for the coils, stock bar control boxes are new from KandStech.com. Bike was a 1981 KZ1000 CSR so it has a perm mag 3 yellow wire stator setup.

So my final question is would you spend the $83 for a Rick's Regulator Rectifier from Z1Enterprises or just monitor the battery for weeping electrolyte?

Videos here --> at the bottom video.google.com/videosearch?q=jasonfagan.com&hl=en






Post edited by: sheik*yerbouti, at: 2007/07/17 22:28

Nice bike!
I'm surprised that you're getting 14 - 15.5 volts at 2500 rpms. I get about 13 volts there, and the voltage comes up to 14.5 at 4,000 rpm.
Your voltage regulator is doing it's job at 4,000, clipping the voltage to 14.5, but it's allowing some overvoltage at lower rpms.

I have no idea about the battery problem, but WOW! I had to respond to the photos.
Awesome bike. :woohoo:
You did an excellent job.
Now my KZ750 is looking a little bland to me.
Great work.

Wooooohooooo :woohoo:

That is one nice ride!

I think I'd put the battery the right way up and check reading with a meter to see if right side up made any difference.

Thanks for the kind words fellers!

Tonight I started her up again and let her idle for about 2 minutes with blips to keep her running. Once warmed up the idle voltages dropped, bouncing from 12-15 volts and revved to five grand with the headlight on high at around 14.5 - 15.5 volts.

I'm calling it ok for now. The battery didn't warm up much at all, the reg/rec was hot, but I was able to press my hand firmly against it and it wasn't too hot to hold on to, with no airflow and 89F that should be ok.

Can't wait to get my upholstered tail back and take her out for a real ride this weekend!

I'll tell you this, the couple times I rode through town, there wasn't a moment without someone totally gawking at her, eyes glazed over, mouth agape...

I am very proud, and my many bike riding co-workers are amped to see her Friday after many progress pics and now especially with the google videos...

Later chaps!

FYI: If you have a cheapo multimeter, measuring voltage at the battery can be problematic. I think the meter has a response time and a cheap meter many not respond quickly enough causing the meter to "bounce" as you put it. It can be kind of misleading. I am sure one of the 'lectric gurus can weigh in on this.