My NC30 runs great when it wants to but doesn't like starting.
I have followed the electrical testing guide on here for regulator/rectifier problems and found it was the battery not holding charge. With a new battery freshly charged by the optimate4 it starts and runs fine. If its been on charge Friday night it will start on the button until about wednesday at which point it will start then conk out, starter motor spins up but it needs a bump to get running. By Friday morning its stone cold dead. The reg/rec is still working correct according to the haynes and guide so I assume the alternator must be ok. most trips are 26 miles around with the lights on, could it be I am just not doing enough to charge the battery?

I have tested the battery today (friday after charging it last weekend) and its steady at 11.70v enough to spin the starter but not kick into life. If i put one sensor on the red+ battery terminal and the other on the kick stand I get a reading of 11.70v should this happen or does this mean I am leaking power into the ground? I don't have a rubber foot for the kick stand.

anyone got any ideas?

I would say 11.7 is too little in a fully sorted battery. I get 13v or more when fully charged.

ref the earthing thing...seeing as the neg terminal is a wire that bolts to the frame I rekcon you should get the same reading? Might be wrong, electrics is voodoo

i got that reading as i charged it last week, ie its now run down, when charged it is around 14v (i think) the query is, should the footpeg be acting as an earth, and could that be slowly draining the battery? or is something else doing it?

Sounds like the battery has had it.

The whole frame and anything metal connected to it acts as the earth, this alone won't use any battery power!

So if im reading this right your charging systems fine but your batterys going dead after a few days.

Righty-o.

Step 1:

Peform a current 'leak' test. This will check that you dont' have anything draining the battery.

Take off the earth lead from either the frame or battery whatever is easiet.
Set your multimeter to Amps.
Put one lead onto the unbolted end of the earth cable and the other probe to where the cable bolted to (battery or frame depending on which side you removed), this in effect bridges the gap you've created by removing the earth lead with the meter.

Make sure the ignition is off.

Start with the highest amp setting if its a manual meter and switch it down until you get a reading to avoid blowing the meter.

You should have no more than 50ma, anymore than this and its draining the battery.

Step 2.

If you dont have leaking current fully charge the battery and connect it to the bike and put the dipped beam on for 30 seconds to remove the float charge.

Keep the battery indoor but not on a concrete or metal surface and measure the voltage everyday. A significant drop will indicate a defective battery cell discharging the battery.

Step 3.

If the battery isn't discharging on its own and there are no current leaks you have a defective charging circuit.

Finally, everything metal thats bolted to the frame will act as an earth ^_^