650ss battery voltage fluctuation

What is the charging setup?

What do you mean by  between 8 - 1 V ?

Is it the same regardless of engine revs?

Tony

Al will no doubt be here shortly. But since the battery itself is the main voltage regulator  the volts can only drop abruptly if a huge current is drawn, or if there is a fault inside the battery. If there's no smell of burning wires, I would suspect the battery. Where did you check the voltage? Over the terminals, or somewhere downstream?

The battery should be doing most of the regulation, so a significant change could be down to the battery trying to 'go on holiday' the Reg/Rect would be the next suspect (along with the alternator) but if either reduced the charge rate, you shouldn't see it (until the engine stops or the light go out).

So an actual drop in battery voltage long enough and low enough to up set the running would be bad connections and or a battery on the way out.

Often when riding I notice the ampmeter  at zero  but after a few minuits stop (with the lights on pilot) and the motor on slow tickover. the charge  returns and  once riding increases with revs ,. then settles back on zero. The battery  if checked with my intelligent charger shows 14.4 v (fully charged) after a very short charge. To me this says that the voltage control (zener) is doing it job and there is more than enough charge availiable . Perhaps you are just seeing  action which is normal for your bike. How does the battery behave if you charge it off the bike?.A decent battery should run for hours with no charge unless its fighting some bad connections.

If the actual battery voltage falls significantly below its nominal 12V enough to stop the bike then the battery and/or its main connections are in serious doubt. Or actually there might be a serious short 'stealing' the power. Charging and testing the battery off the bike I wouldn't think will show up very much as the vibration and variable load might be the triggers for this behaviour. Yes a good battery say 9Ahr if reasonable well charged goes off charge, will then run the bike (no lights, normal coil ignition) for about 4hrs (50mph for 200 miles)

If you monitor the battery/running voltage down stream a bit, ie at the reg/rect or even Zener terminal, then you might get some more facts to work on, but at this point the original problem of dropped battery voltage can get nebulous. If the problem continues then please get directly in touch.   aoservices.co.uk or through Roadholder.

Alan didn't mention that he sells something called a Battery status monitor. Fitted one on a BSA single where I made a new electrical system. Much easier to be able to check when riding, a multimeter difficult to use riding.  Found it very useful. So I'll get two more for other bikes.