hey guys as a few of you know already I have been having trouble with my battery etc, and well the other day my clutch cable unhooked inside the housing but i didnt have any tools with me, so feeling like a twat i called emergency break down as i get it free.

So he came out and i basically took the tools off himand sorted the problem but while he was there i got him to check my battery, now both of us were confused.

when i have the bike running lights off the battery is receiving an 11.3v charge from the alternator, then with the lights on and brake light on the charge goes up to 12.5v

the problem is this isnt enough of a charge to replenish the battery and i am ending up with a dead battery, i dont know if it is the alternator or the regulator/rectifier, does anyone have any advice that could be causing this or how to combat this problem as I have checked and already Im gonnahave to fork out £45 for a battery and acid but the alt and reg/rec are pricey so i would rather get the right one of the blocks.

Hi.

I must first point out that I do not have any real knowledge or experience of automotive or motorcycle electrics,  but I've had a look in my GS Haines manual and Chapter 8, Section 32.6 states the following below (i've compressed it slightly).

Output test - under load
6 Start the engine and warm it up and turn the lights on.
7 Let the engine idle and connect a multimeter set to the 0 - 20 volts dc scale to the battery terminals (it makes the point that the multimeter positive lead must be connected to the positive battery terminal and the negative connected to the corresponding battery negative terminal).

Slowly increase the engine speed to 5000rpm and note the reading obtained.  At this speed the voltage should be 13.5 to 15.5 volts.  Stop the engine and turn off the lights.  if the voltage is outside these limits, perform a no-load output check and also check the the regulator/rectifier (you'll need the Haines Manual for guidance on how to do those tests).

Haines Note: If the voltage is below 13.5 volts, then it is more likely that the alternator is faulty.  If the voltage is above 15.5 volts, it is more likely that the regulator is faulty.  Haines hint: Clues to a faulty regulator are constantly blowing bulbs, with brightness varying greatly with engine speed, and battery overheating, necessitating frequent topping up of the electrolyte.

Hope this helps  .

bassman

Bassman proves you don't have to be an expert if you can read the book!

It sounds like it could be a dead alternator to me too, or a battery with a dead cell.  There are a few things to check before condemning the stator coils or magnets.

Follow the alternator wiring cable from the left side of the engine to the connector that leads to the regulator/rectifier.  Inspect the cable for damage.  There are three wires inside that cable.  Separate the connector and make sure those connector pins inside are clean and tight.  Bad connections to the alternator will of course act like a bad alternator.  If there is an alternator problem, it's likely the problem is there.  This is true of all the electrical components of our bikes.  Connections are the weakest link of the chain.

The second thing to check is remove your battery, charge it with your trickle charger, and make sure it will obtain 12.6 volts at rest.  Then let the battery sit for a day and make sure it still measures 12.6.  If it passes this test, you can take to the auto parts store and they'll do a load test for you.  There are three ways batteries fail; internal leakage, dead cell or cells, or fail the load test.

I always tell people to check the health of their battery because other than connections, it's the weakest part of the electrical system.  My father once bought a new battery that lost charge internally after a day or two.  After a month of problems and the mechanic insisting it passes the load test, my dad insisted on another new battery.  Problem gone.

Your problem fits a dead cell.  If you do have a dead cell, your battery will measure about 10 volts at rest instead of 12.6.  Your regulator will see this and not try to charge the battery much above its "normal" terminal voltage.  This problem is screaming "bad cell".

iirc there is a thread (very detailed) showing how ot check your charging system. maybe it was by kerry, or gsjack, don't remember.

I think this is the link ohgood is referring to: http://gstwins.com/gsboard/index.php?topic=38480.0

What a great site this is !!!!!

see the problem is yes the volltage when charging is lower than it should be which does suggest alternator but then when i turn the headlights on the charge voltage goes up which suggests reg/rec but even with the headlights on there is not enough charge to charge the battery, and now the battery is dead, is there any way i can check what is causing it without a voltmeter as i dont own one and i live in the middle of nowhere so getting one isnt that easy.

You should check your voltages at 5000rpm as weird things happen at idle.  Your bike is probably not capable of charging at idle (normal).  So don't spend any $$$ until you test it at higher rpm.

it was tested at 5000rpm by emergency recovery guy

Just because your charging voltage won't climb enough doesn't mean the battery isn't bad.  Dead cells will keep the charging voltage low.  Ignore my electrical advice at your peril!

so  you reccom its just the vattery then?