
Occasionally, I turn the engine off then when I try to restart it the battery's dead. A jump start from a car battery gets it running again, and it'll run all day.
If I keep it running and check the voltage, I find that it's low - around 8 or 9 volts. The volts do rise with an increase in engine revs though but only by a volt or so.
If I charge the battery overnight and then run it, the voltage is ok - 13.8 volts, increasing with engine revs. It'll be fine for a couple of weeks then it'll fail again.
I've replaced the battery and also the regulator/rectifier, but it's still doing it.
Can anyone please help?