Overcharging r/r

[Capt K]

Help, Need Electrical assistance. My 88 vmax has been cooking batteries since i bought it 5yrs ago. I added a voltmeter to gauge cluster to see whats happening. Just replaced r/r for 2nd time because all lights were pulsing & i pulled out another melted swollen battery. New battery & r/r now reading 14v at idle, 17-18v at revs. Disconnecting +wire from r/r to battery & checking voltage from stator reads 50-75v (with no load) at revs.

I found youtube videos that show when the power supply to r/r dips below 12v, this can cause r/r to exceed the pre-set 14.5v charging cap. I also read the discussions here detailing the weak-link factory crimp of the r/r + wire to the main 30a fuse + wire. I corrected these problems & still have 17-18v at revs.

Any ideas? What about putting a toggle switch on the + wire of r/r to periodically turn it off & reduce overcharging to battery? Ive read mixed reviews of this solution: can create extra heat & wear on stator, & potential high voltage spikes to system by interrupting 3phase charging cycles.

Any advice appreciated!
Thanks
K

 

[MaxMidnight]

Last point first, a properly functioning alternator, r/r and wiring will not overcharge a battery. Fitting a switch won't fix the problem.

Doing the crimp will probably improve the voltage available but that isn't your issue. No reason not to do it though.

First thing I would do is to remove and clean all of the earths. I would also run an earth wire from the r/r to the main earth.

What r/r are you using? If it is a cheap clone then I'd replace that with one from a known manufacturer and supplier.

 

[Fire-medic]

Yes, I suggest following MaxMidnight's advice. you need a new quality R/R. The voltage is not being controlled properly.

 

[Capt K]

Thanks for the advice guys!

All the bolt connections on the passenger foot peg plate with r/r are spotless. I get a solid 12v on volt meter grounding to r/r housing & from bolts to frame. I also already have a wire running directly to battery neg from r/r.

The r/r's I've used are from Amazon. Where would you suggest getting a new one? Dealer?

I will clean all the rest of ground locations as you suggest. And try another r/r. Will keep you posted.
Thanks

 

[CaptainKyle]

Are you using the old style regulators?

 

[rcfoggy1]

I went thru the same thing, thru 2 batteries several regulators,
all cheap regulators do is cost you time and money.
buy a good later style regulator and your problems will go away. they will cost you 180-200 .
u just have to spend the money ,

 

[Capt K]

Yes, I've used the oem look-alike shunt style r/r from Amazon $15-20. But they evidently are cheap clones as MaxMidnight suggests & didnt last 1yr.

So for r/r upgrade which is best?
•SH775 series type regulator (using SCR & non-shunting)
•FH020AA MOSFET shunt regulator

And do these fit inside passenger footpeg? They look much bigger than oem.
Thanks

 

[gentsvmax]

Thanks for the advice guys!

All the bolt connections on the passenger foot peg plate with r/r are spotless. I get a solid 12v on volt meter grounding to r/r housing & from bolts to frame. I also already have a wire running directly to battery neg from r/r.

The r/r's I've used are from Amazon. Where would you suggest getting a new one? Dealer?

I will clean all the rest of ground locations as you suggest. And try another r/r. Will keep you posted.
Thanks

Check out Roadstercycle.com, get his best all in one kit.

 

[VMAXXIMUM]

Get it from Sean at Morley's Muscle. It will fit the stock location and be plug in ready. Literally, unbolt, un plug and remove. Slot new one in bolt up and plug it in.

 

[Capt K]

Follow-up:
So ordered & installed sh775 r/r. Working great! Max voltage is 13.9 at speed & r/r does not seem to get overly hot.

Locating it was the only tricky bit, definitely too big to fit behind footpeg like oem. But with a couple brackets, it sits nicely on the square-end of driveshaft housing. Adding a couple mini heat-sink fins creates a good airspace between the two.

Thanks again for all the advice!
K

 

[Bill Seward]

Mine runs cool enough to live under the seat where the coils were located before changing to COPS

 

[Bill Seward]

In my opinion, the Series regulator is the only way to go. Wire it directly to the battery, through a fuse, and you will get the maximum charge to the battery.