[jm1515]

I own an 01 750. In March '03 I installed a Yuasa MF battery, bought an Electrex RR26 as a precaution against stator failure. I also installed a VDO voltmeter to monitor things. This past April @25800mi my stator went anyway, and I replaced it w/ a new Electrex G5. The installation went fine, and on my initial 70mi 'test' ride w/ my totally Electrex charging system, all seemed OK. I was seeing just over 14v most times.
During the first leg of my next ride, I noticed the voltage started around 14v, then waivered between 13.5 - 13.8, finally settling at just less than 13.5v. Hmmmmm....
I watched this for ~ 5mi and finally had seen enough. I pulled over, and after checking all connections for heat, looseness etc, I yanked the Electrex RR out of the system and reconnected the stock unit still mounted under the battery. Voila'....I immediately got 14.5v - 14.8v at most times over 2500rpm for the next 190mi, and for the 2700mi I have put on since then w/ the OEM RR. Obviously (to me) there had to be a difference in the output charging voltages btw the Electrex and the OEM, all else being equal....
When I got home. I wrote Electrex tech support abt this difference in output as measured in the 'real world'.
To make a long story short...the founder of Electrex followed up himself. Ritzo Muntinga emailed me back and arranged for tech support to check my RR. It took nearly 2 weeks for them to get back to me after I mailed the unit to them, but they found my RR to be turning on and off (shorting out??) occasionally when it got hot. They replaced my 13mo old RR (1month out of warrantee) w/ a brand new unit...I just installed it today!
Needless to say...I am very happy w/ Electrex's service on this issue...they did not have to do what they did, seeing as how my RR was out of warrantee, if only by a month....Thumbs Up!
Today I will ride w/ my new Electrex charging system...I am very interested to see what my voltmeter tells me.

 

[jdegreif]

I have just one question, maybe someone who knows can answer. Once the battery gets fully charged won't the regulator cut voltage back to somewhere around battey voltage? Wouldn't that explain the voltage drop? Or does it put out a higher voltage than the battery?

 

[IASKRU12]

Somebody correct me if I am wrong. The R/R does put out higher voltage than the battery. This is done on purpose. I believe that the ignition system is run directly off the battery. The stator generates AC that is converted to DC by the R/R. Because of the variation of the engine speed there isn't a consistent voltage flow. The R/R conditions the power by keeping the voltage steadier and topping out the voltage so there aren't any high voltage spikes. This conditioned power is used to charge the battery as you ride and it gets drained by the ignition system.

I believe (I know even less about cars) this is different from cars, in that the ignition system is generally powered off of the generator on the car.

 

[jm1515]

Re: My Electrex RR experience...Voltage report

After a quick 60mi jaunt w/ my new Electrex charging system, I'm a bit dissapointed.
To answer the questions above....an RR should have a regulated output of ~14v or more to charge the battery. The OEM unit puts out 14v~15v as per the tech manual. The Electrex unit does not put out that much, I think because....
I had been running 2700mi w/ an Electrex stator and OEM RR, while I waited for Electrex to respond(above). I consistently, constantly, always, everytime saw 14.0v~14.8v on my VDO voltmeter (connected directly to the battery w/ a switch) when at running rpms.
After hooking up my brand new Electrex RR26 they so kindly sent me, I ran 60mi yesterday and saw NO MORE than 13.8v at any time. This kinda ticks me off because...I'm right back to square one as I posted above!
I am grateful that Electrex took care of me, but their own website says that an RR should be putting out a regulated ~14.4v at all times to charge the battery. I'm going to check wiring and do some measurements today, but I doubt anything will change...
So I have a question for the techies out there>> Which would you rather run with...
OEM RR showing 14.2~14.8v at the battery when running OR
Electrex RR showing no more than 13.8v ???

 

[jdegreif]

It would be nice for an electrician to jump in, but a fully charged battery is around 13.2-13.5 volts (whiich you should almost never have a FULLY charged battery while running, only when a charger is connected. When the charger is disconnected voltage drops) But charging amperage is also an important factor...right? So if the voltage output was 13.8 but at a rate of 20amps then everything would be ok? Or am I wrong in this in that when the amperage is up like that so is the voltage? I should have paid more attention in motorcycle mech and auto mech shop in high school.....I most likely would have forgotten it anyway....it was WAY too long ago

 

[MokiMan]

That's correct on the fully charged voltage (sometimes called "float" voltage). Lead-acid battery charging systems are self-regulating. That is, the system voltage (what comes out of the regulator) should be nominally 13.8 volts. When the battery charge level is down say, after starting the bike, the initial charging current will be higher because the battery's terminal voltage is lower. As the battery charges the voltage rises until it gets to about 13.5vdc or so. A disconnected, fully charged battery will show about 12.6vdc terminal voltage.

The current flowing into the battery (or out for that matter) is determined by the voltage difference between the system voltage and the battery voltage. It is limited by the battery's internal resistance and the amount of current the regulator can supply. As the voltage comes up in the battery, the charging current naturally tapers off. There are other changes that occur chemically in the battery that limit charging current, too.

Generally, anywhere from 13.8 to 14.5 or .6vdc system voltage is considered safe for a typical lead-acid battery electrical system. If you go much higher than that you stand the chance of overcharging the battery (boils out the electrolyte).

I believe that 13.5 volts from the R/R is too low, contrary to what Electrex told ED. At that voltage, I don't think the battery will ever get properly charged. On a cold winter's day start, you may need every last ampere-hour the battery is capable of to get the bike started.

 

[jm1515]

Great explanation MM. I also think the Electrex RR must put out more than 13.5v, just not all the time! I'm sure they make a fine product, but my voltmeter is all over the place when I ride. This past weekend, I did ~450mi w/ Electrex RR and stator. I got readings as low as 12.8v and as high as 14.5v when running...didn't matter how high/low the cruising rpms (altho most of the time the readings were right around 14v) . Before they sent me a new RR, the OEM RR gave me 14.2v~14.8v, never lower than 13.5, consistently for ~2800mi (that's why I got an analog vm, so I could stress out like this!). I know their RR senses voltage internally, which is different than OEM, so I guess it just shunts AC more often than the stocker. I just hope this is not bad for my new stator....

 

[jm1515]

Going to throw this out there for anyone who has the ElectrexRR and is considering a voltmeter, esp an analog type like mine...

On Starman's VN750 page there is a discussion of the differences in the Electrex RR...it senses voltage differently (I knew that) and regulates differently than the OEM. I also knew that.
What I did not know (and neither did Electrex, I guess), is that sometimes this will cause the erratic readings I describe above, esp on analog meters. MokiMan suggests a .1mfd capacitor bridging the terminals on the meter, to smooth out the readings, as well as wiring the meter directly to the battery thru a relay or a switch, to eliminate voltage drop. I was using the accessory terms in the headlight bucket.

I did both, oh, about 4months ago....posted the results on Y! I used a .1mfd metal film cap available at RadioShack, and ran the wires directly to the battery, using a good on/off switch.

Bottom line....my meter is now steady as a rock, always reading somewhere between 13.7 ~ 14.v, verified by my digital VOM.
So I guess I'm happy...for now.
I have no problem w/ my all-Electrex charging system, and would recommend to anyone...