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Discussion Starter #1
Anyone know of an automotive electric shop in Los Angeles that would be game to service the alternator out of a Brutale 750? Based on other posts, it seems like a lot of shops are sissies about working on bike alternators or the MV one in particular because the regulator is built-in.

My last battery got worn out far too quickly and I'm pretty sure it's because my bike is pushing 15 V and overcharging it. I checked with Yuasa hoping the spec in the MV manual was overly cautious, but Yuasa said 15 V would indeed ruin the battery.

Going to take a crack at removing the alternator this weekend, would love to find somewhere local to take it for a check/rebuild if needed

thanks
 

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Chris,
I recall 'Gremmin' having posted ND part numbers for (one or all of) alternator, rectifier, and regulator here in this forum, search and ye shall find.
 

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Chris;
Read the 7 page explanation of how the charging system works in the service manual

My Brutale 910R idles at 14.79V, above idle 14.81V ...... battery lasted 8 years, standard Yuasa

:wink2:
 

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Discussion Starter #5
Chris;
Read the 7 page explanation of how the charging system works in the service manual

My Brutale 910R idles at 14.79V, above idle 14.81V ...... battery lasted 8 years, standard Yuasa

:wink2:
Oh man, I'd love to find out that I'm chasing ghosts and can just get a new battery. Although I'm nearly at the point of having my alternator removed, but those trials belong in a different thread

My Yuasa battery already needs to be replaced after only a couple of years. After a few days of riding, it struggles to start and voltage drops as low as 9V during start (even fresh off the charger, the start load will drop it to 10.5V but it'll still start confidently). What I'm trying to sort out is whether my charging system is overcharging and prematurely wearing the battery. I don't want to have to buy new battery in another couple of years and constantly wonder whether my bike will start. I figured the best way to be sure of that would be to have the alternator tested out on a bench.

After trickle charging my battery over night, it reads 12.6V. When the engine is at temp, from idle up to 2,000rpm I've had voltage readings of:
first time starting after reinstalling battery (just starting, no ride) - 15V
next day, first ride of 8 miles/6 on the highway, outside temp 60ºF - 14.69V
bike parked for 9.5 hours, outside temp 62ºF - 14.98V at idle to 2,000rpm. At 3,000-4,000 rpm, voltage fluctuates semi-rapidly anywhere in the range of 14.3-14.8

Workshop manual says 12.6-14.3V @ 2,000rpm

Also have a Microtec, but if I'm understanding posts on another thread, the Microtec bypasses the "sense" connection so the ECU shouldn't be a factor?
 

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Chris;
To me it seems a connection issue.....

disconnect the battery, clean the terminals apply Dielectric grease
clean both ends of the wire from the alternator, grease
inspect and clean the charging system fuse, grease
inspect and clean both ends of the wire from the battery to the solenoid, grease
then....
go to AutoZone they'll test the charging system and battery
come to my house, I'll test it
Best go to Peerless Auto Parts and John will use the latest electronic test equipment ..... it's free
 

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Discussion Starter #8
Chris;
To me it seems a connection issue.....

disconnect the battery, clean the terminals apply Dielectric grease
clean both ends of the wire from the alternator, grease
inspect and clean the charging system fuse, grease
inspect and clean both ends of the wire from the battery to the solenoid, grease
then....
go to AutoZone they'll test the charging system and battery
come to my house, I'll test it
Best go to Peerless Auto Parts and John will use the latest electronic test equipment ..... it's free
Alternator is already off the bike. I already tested the bike on a few different occasions with the battery in different states of health, and got overcharge numbers every time.

I checked all the connections, and the charging fuse, and everything was spotless (I live far enough inland that I don't have the salty beach air like you do). I gave it all a scrub and dielectric coating anyway.

I found a place a bit closer to me than Peerless. C&R Auto Electric. I'm dropping it off to them tomorrow morning.

Did anyone ever get a definitive response about whether a Microtec utilizes the 'sense' cable in any way? I asked xbikes in an email a few days ago and still don't have a response. They're pretty slammed right now. I imagine the shop is going to ask me about it and I'm trying to have an answer ready
 

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bike parked for 9.5 hours, outside temp 62ºF - 14.98V at idle to 2,000rpm. At 3,000-4,000 rpm, voltage fluctuates semi-rapidly anywhere in the range of 14.3-14.8

Workshop manual says 12.6-14.3V @ 2,000rpm
I believe the workshop manual is basically stating the spec of the regulator ie it will regulate output voltage to no higher than 14.3V. Most charging system will limit charging voltage to no more than 14.4V so as to not damage the battery. Your 14.98V suggests to me the regulator is on its way out.
 

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I believe the workshop manual is basically stating the spec of the regulator ie it will regulate output voltage to no higher than 14.3V. Most charging system will limit charging voltage to no more than 14.4V so as to not damage the battery. Your 14.98V suggests to me the regulator is on its way out.
Well you're totally incorrect.......
Check page E-21 of the 1000S to 312RR F4 Manual

at 2,000 rpm

""with the regulator at 25C the voltage must be 14.5V + - 0.6V
N.B. At different temperatures the voltage can be between 13V and 15.5V"

my '08 910R reads 14.79V at idle and 14.81V above idle ......stock Yuasa battery lasted 8 years, never on a tender

34,000mi

:smile2:
 

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Well you're totally incorrect.......
Check page E-21 of the 1000S to 312RR F4 Manual

at 2,000 rpm

""with the regulator at 25C the voltage must be 14.5V + - 0.6V
N.B. At different temperatures the voltage can be between 13V and 15.5V"

my '08 910R reads 14.79V at idle and 14.81V above idle ......stock Yuasa battery lasted 8 years, never on a tender

34,000mi

:smile2:
Noel,
Charge feed check (page E23 of F4S manual) says:
@2k rpm -12.6V - 14.3V

E21 refers to check/trouble shoot of a part of the charging system, where there's a fault in the charging system of some kind (light on dash on).

I don't know the particulars of each bike, but virtually every piece of info I've read says standard battery are charged at 13.6V - 14.4V whilst AGM batterys are charged at slightly higher voltage, ie up to 14.8V, perhaps MV Agusta factored in AGM battery for your 08 910R. I will find the reference article from Century Battery (Australia's distributor for Yuasa) and post it. I've also built solar charger for my camper, and the regulators regulate output to pretty the same range as above. I know they are very different regulators (bike/solar panel) but at the end of the day (IMHO) it is there to protect the battery and the various load on the circuit.

http://www.centurybatteries.com.au/content/documents/battery-talk/issue-2-battery-talk-battery-charging.pdf
 

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Wtf?

Paul you have no clue......
The page I posted, E-21 is total bullshit.... I posted it to see if you'd catch the mistake
WHEN THE RED LIGHT IS ON ..... IT'S NOT CHARGING!!!

Page E-23 is wrong also......you want high charging voltage...... because it cuts down the CURRENT!
Current is what tears things up......ask a TIG welder ?
Remember 6 volt batteries and how big the cables were?

Psst....... all MVs use AGM batteries, not just my 910R......it charges @ 14.79-14.81 volts.....
my original battery lasted 8 years

and there are Forum Members that get 2 years to a stock battery!

Most vehicles used to come with Amp guages......they move as required...... now they may have
voltage guages......they don't move...... but people are too stupid to realize why.....lolol

Just so MORONS won't ask stupid questions ?

Just for you General Motors recommends a system voltage of 14.8 -15.2 volts......
I have a '66 El Camino it gets 6-7 years to a battery......it has 526,000kms on it the alternator needed
a bearing ~350,000.....2 of the 4 headlights are original

In another thread you said your bike wouldn't start because of a corroded fuse......there isn't one in the
starting system...... it's in the charging system

After 58 years off and on as a professional mechanic I learned a few things......
You should stop reading manuals and spec sheets....

AND GO RIDE YOUR BIKE

:grin2:
 

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Discussion Starter #13
After 58 years off and on as a professional mechanic I learned a few things......
You should stop reading manuals and spec sheets....

AND GO RIDE YOUR BIKE

:grin2:
That's actually the approach I settled on with the alternator. I couldn't find a shop that could bench test it, but found an auto electrician who gave it a college try to find someone who would. He said I ought to get a new battery and see what's happening in a year. The spike in the voltage that I was seeing could be from the alternator trying to overcompensate for my old battery that's borderline. The only replacement voltage regulator I found was around $120, so I wasn't going to replace that "just in case." Got a Shorai LFX19A4-BS12, which handles charging up to 15.2V just fine according to Shorai's specs, plus it's lighter and packs more CCA than the oem Yuasa. So for now I'm closing the book on my alternator repair and have it reinstalled on the bike, and as soon as I take care of all the other things I'm tinkering with, I'll GO RIDE MY BIKE!
 

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Paul you have no clue......
....
You should stop reading manuals and spec sheets....
:) LOL, with respect Noel, I can't reconcile this ^^^

In another thread you said your bike wouldn't start because of a corroded fuse......there isn't one in the
starting system...... it's in the charging system
I recall posting something along that line, but I wouldn't have said the 40A fuse is part of the starting system, because the manual says it's part of the charging system somewhere (I can't recall, but it's in there somewhere). The battery on the other hand is part of the starting system, and if it's not properly charged because of intermittent fault caused by a dud fuse...

Psst....... all MVs use AGM batteries, not just my 910R......it charges @ 14.79-14.81 volts.....
my original battery lasted 8 years

....
Just for you General Motors recommends a system voltage of 14.8 -15.2 volts......
Yes, I concede on the voltage Noel, I've tested it on my Brut and it was between 14.3V and 15.2V depending on revs, and it's all good battery health wise.

It still surprises me given voltage sensitive load/equipment like the SPU and light bulbs, AND also on the bikes without electromagnet rotor the Reg/Rect is usually designed to limit charging voltage to 14.4V. IIRC my F4 has a stator and flywheel and separate R/R unit, I will test this when I get home.

EDIT: F4 with stator, fw and RR 14.4V tested. Have a look at all these regulators, most of them have the V Set at approx 14.4V.

http://www.remco-automotive.com/Catalog/RegulatorCatalog.pdf


...and no argument from me re' current.

AND GO RIDE YOUR BIKE

:grin2:
I know you're well intentioned Noel, but some time I do wonder if that

" :grin2: "
could also have a grumpy teacher element to it :)

 

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Paul;
Please stop posting erroneous bullshit numbers and your conjectinons as to how things work.......

There are Forum Members that speak NO English ......and rely on a translator to make sense of your posts......

Translators are horrible with technical terms .......you are not helping at all

:frown2:
 

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Not exactly elecronics wizards you lot ..

Interesting thread -- with a hefty dollop of "curmudgeoning" -- >:) -- and not that mucho apparent deeper knowledge of electronics ..

1: There are two types of "providers of electric Voltage AND Current" on motorbikes .. An AC "alternator" usually 3-phase AC -- (As mounted on ALL MV's) or an old fashioned DC Generator with commutator "brushes" or "coals" (Which is NOT used on "modern" MV's) The Voltage from 3-phase AC "alternator" gets rectified into DC Voltage by 8 rectifier diodes in a "3-phase-rectifier bridge"

2: This VOLTAGE is delivered to the "VOLTAGE regulator" which is built into the "Alternator assembly" on MV's -- (On DUC's the parts are separate, they run an 18-pole 3-phase "Flywheel" type "Alternator" with static winding coils, and permanent magnet rotor which lives partly immersed in hot engine oil ... You do not want your VOLTAGE regulator in there with it.) The MV AC alternator uses an "open air" external Alternator with no magnets, but a rotor coil fed from the DC side of the Rectifier bridge, and controlled from the Regulator. The Ducati system is a "loss" controller -- any voltage above the set "charging voltage" is dissipated as heat (hence the regulator is a finned alu box sitting somewhere "windy" )

As long as there is no load on the AC output form the "Alternator" the voltage will be very high -- I've measured up to 80 volts RMS AC from a Ducati 3-phase "alternator" at 5000 RPM The regulator has to cope with this voltage in a "no load" situation -- This is usually what kills Solid State (Transistorized) Voltage regulators -- You have a fault that disconnects the load from the output of the regulator and the Voltage on the input gets very high .. The "disconnect" fault may be intermittent due to corroded contacts/connectors (Naaa. surely not, on an Italian bike .. :D) Resulting in voltage spikes on the regulator input -- that can damage the regulator in subtle ways...
The regulator in the MV "Alternator Unit" is a simple 2-transistor system with an IC controller .. According to the "mv-agusta-750-electrical-system" manual it regulates the VOLTAGE down by regulating the Rotor coil CURRENT - so there is theoretically no voltage drop (or very little) across the Regulator, so it does not have to dissipate heat.
BUT: the MV Alternator has "brushes" -- They can be worn or damaged .. I do not know if they can be serviced or checked .. but it ought to be possible --

Remember Ohms Law: U (voltage) = R(resistance) times I (Current) U=R x I AND Energy (Watt) = U x I So for the same "energy" (W) a higher voltage equals a lower current .. For a higher current you need thicker wires to compensate for voltage loss over the resistance of the wires ..

If your battery ha an unloaded voltage of say 12,8 V -- and you load that with the Wattage of your entire bikes energy use (Headlamp, ignition ECU etc.) it will drop a little.
The more it drops the higher the "internal resistance" of your battery is .. You can calculate this resistance .. It is very dependent on the condition and capacity of your battery.
A poor battery may have a high internal resistance .. this means that while it may show a high unloaded voltage, it will not deliver much starting current, since the voltage will drop very low when it has to try to deliver the very high currents needed by the starter motor .. You then procede to charge it with your Tender/charger and it very rapidly recharges to a good voltage .. Such a very fast "recharge" is a sure sign that the battery is poor .. NOT that it is "Good" -- Yor MV's charging system will NOT detect this, its even dumber than you, so just regulates the voltage down. Most "Tenders" can not check the battery for this condition -- regardless of the hype the manufacturers advertize .. To test for it would require the "tender" to be able to draw a test-current from the battery that is at least within the same order of magnitude as the starter motor .. You take one look at the gauge of the "tender" wires, and you should know that they would just start going up in smoke if you tried .. :nerd2:

The ONLY way of testing if your "alternator/regulator" is doing its job is to MEASURE the CURRENT that flows into or out of the battery (A GOOD battery!!!) .. To do that you will need a "Clamp" Amperemeter or one that will handle at least 20 Amps through current -- (12V x 20A = 240 W) Your bike will not use more than that amount of "Wattage" if no "extras" are switched on -

So! Fit a proper battery before "testing" your Alternator .. and YES! Lithium batteries ARE good -- If they are a proper quality and have enough "Ah" (Ampere-hours) or "Wh" (Watt-hours) 4Ah or 48wh is a MINIMUM --
My Duc ST4S has a 4Ah "chinese" LiFePo 14,4 V battery -- It works perfectly -- The Sealed Lead-acid Yuasa on my F4 is now 4 years old an showing no degrading performance.. It is kept on a C-Tek 90% of the "garage time" and stored for winter in my electronics lab, on the C-Tek, at normal room temperature .. The same will happen to the Li battery from the Duc -- When the F4 battery "expires" it will be replaced with a custom made Li-Ion "pack" with 6Ah and 300 Amp starting current.

I could go on, but I will stop ranting now and GO RIDE MY BIKE .. >:)
 
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