High Volts

[cvincer]

Decided to replace my old tired lead acid battery (230cca) with a new AGM (Absorbed Glass Mat) battery  (310cca)

Had the new battery tested before leaving the battery shop, & it showed  12.8v  & 325cca.

Installed & went for a ride, then applied the volt meter  ........  16.5v @ 3000rpm    &  16.75v @ 6000rpm.

Re-installed the OLD battery      "         "           "                         14.24v & 3000rpm   &  14.43v @ 6000rpm

Re-installed the new battery   "          "           "                         16.5v @ 3000rpm    &  16.75v @ 6000rpm.

Connected the new battery (briefly) to a 1amp battery charger + voltmeter & got steady 14.6v

I've tested the reg/rectifier & stator as per Haynes & everything is good.

5 days after going for a ride the new battery still shows over 13v, a few more days & it's down to 12.95v.

So, has anyone any idea re the   +16v  charging when I'm riding the bike  (would hate to melt my new battery).  Thanks

[fret not]

What, if anything, other than the battery did you change?  Your indicated results seem a bit odd assuming the RR unit is properly functional.  Maybe the new battery has not yet been fully charged and is drawing more from the charging system.

[Re-Vision]

I bet that you won't have any problems with your new battery.     BDC

[Walt_M.]

If I remember right, the AGM batteries are more tolerant of high voltage but I don't know why yours is showing 16V while running and the old one is 14V unless your R/R is failing. Does the brown reference reference wire have a good connection?

[supervision]

  My educated guess, is that the old battery is so hardened up it won't make 16v, the new battery is probably fine. What I think is happening, is the old brown wire is the problem. They over thought the brown wire in that day, and now all new R/R come with it hooked up inside the R/R, it nowdays is part of the positive wire.  An easy fix for you is to cut your brown wire and spice it into the positive wire right their near the R/R. If you do this it most likely will not go above 14.5.

[Rikugun]

Are all the volt readings you quoted measured at the battery?

I get (max of) mid 15's measured at my conventional battery using a shunt style R/R. This is a relatively new setup so I can't tell you long term effects. Having said that, my '82 Kawasaki with the original R/R charges over 16 at the battery and as long as I can remember and possibly since new.  I typically get 6-7 years from a lead acid battery in that bike.

* during the 2012 season I installed a MOSFET on the Kawasaki which developed a max of 14.5 at the battery. The headlight was dimmer, turnsignals slower, horn weaker so I ended up putting the old R/R back on. Regardless of a nominal 14 or 16 max voltage, water still needs to be added periodically -  perhaps more frequently with the higher voltage setup. YMMV  :)

I've experimented with disconnecting the brown which increases voltage further. I have not tried Supervisions suggestion of connecting closer to the battery source to decrease voltage.

[supervision]

 The brown wire has to be hooked up, or it will charge full output all the time. The brown wire is what the regulator uses to determine when to shunt to ground, problem is as the brown wire gets old it senses a false (slightly lower)condition of the battery, thus it says keep charging when it should have cut back already. 

[Rikugun]

The brown wire has to be hooked up, or it will charge full output all the time. The brown wire is what the regulator uses to determine when to shunt to ground, problem is as the brown wire gets old it senses a false (slightly lower)condition of the battery, thus it says keep charging when it should have cut back already.

Yuuup  :)

[cvincer]

Many thanks for the replies:-

Fretnut         No, didn't change anything except the battery.

Rikgun          Voltage readings (with engine running obviously) taken by putting the voltmeter probes on the battery terminals.
                     It's a sealed battery so no adding water.

Supervision   Just to make sure I've not misunderstood you  ....... re my diagram, I cut the brown at 'A' & join to the red at 'B'.

Walt M          I'll check the brown wire connections at the weekend, B4 cutting as per Supervision.

Thanks  all, for your suggestions

[supervision]

 Yes that is what I am talking about.  I usually do it after it passes thru the connector plug, but if you see enough wire to work with on that side of the plug do it.  The way you show is more direct, which is best,  the shorter the better! 

[supervision]

 If you do it on that side of the plug, you have to cut the brown wire on the other side of the plug an insulate it. 

[Walt_M.]

The only reason not to do this mod is the fact that there will be a constant low amp draw on the battery because the reference will not be switched off when the ignition is off. If you ride daily or at least weekly it will not be a problem but it will bite you for longer term unless you use a battery tender or pull the battery.

[supervision]

 Walt, I remember last time someone mentioned that, I have checked for myself and found it is zero, nota.

[supervision]

  Walt you may have a a valid point, because I have my ground wire as it leaves the R/R going straight to the neg side of the battery, rather than through the wiring harness, that could make a difference, I don't know.

[Re-Vision]

Are you could clean all of the contacts associated with the R/R and make it work as it was designed to operate.
1. Clean Frame Gnd. Connector near front coil.
2. Clean R/R connector pins.
3. Clean 30 Amp. Main Fuse Connections.
4. Clean single pin connector coming from Battery + Terminal.
Only unlikely items left to cause this over charging problem are Ignition Switch, Cable Harness splice connection, Battery Terminals, and R/R Unit.     BDC

[supervision]

 I just went back and read the 2005 thread on over charging by QBS, and maybe the most important part of this is that you want the R/R brown wire to be always hot. Here is the way I did it, take the wires as they leave the r/r,(just above the plug) youm have a brown, a black, and a red, cut the brown wire you should have a short piece that you now splice to the red wire, next, insulate the cut off brown, that goes to the bike, that wire is not needed now and insulate and wrap it to the harness.. Hook up the now modified plug and your charging will now be 14.5. If I didn't make so you get it ask more

[The Prophet of Doom]

I'm with re-vision.  Fix your bike, don't hack at it
That way when your battery get really low in the winter from a lot of cold cranking and lights on, it might actually have a chance to re-charge between stops.

[supervision]

  Cviner, your drawing is correct, it already cuts the brown wire.

[Re-Vision]

Oh Prophet of Doom, Astrologer of Armageddon, Divinator of Destruction, Dreamer of Disaster, Forecaster of Failure, Seer of Sadness, is this your Visionary Verdict?   LOL      BDC

[supervision]

 I like WIDESPREAD PANIC, ever heard them?