Flat battery and no starting.

Hi,
About a month ago I went to my garage to warm up my lovely SV650S K3. After turning on the ignition, the sound of a injection was different than usual. I've pressed the clutch, than a starter button, but no luck. All lights, whole dashboard started to dim, engine was trying to turn, but very slowly. I've also noticed a strange click click sound from under the seat. My first thought was the battery. I've checked the voltage and it was only 6V. After a whole night charging the engine started, but after few tries. It went off after few minutes and I couldn't start it anymore. I didn't know the history of a battery so went to Halfords and bought a brand new, bloody expensive BOSCH battery. After replacing it, the engine started but after I came back from 10 miles ride, the battery was down again (7-8V). All my mechanics told me it's a regulator problem as there is no charging. Bought a new regulator, but it didn't change anything at all. The strange "click click" sound was coming from the starter relay, under the seat. Got a brand new one yesterday, but nothing changed. All the lights are dimming when I press the starter button, engine turns very slowly, and the "click click" sound coming from the starter relay (solenoid) gets really loud.

Does anyone have any ideas?
This bike is everything for me...

Best regards,
Mike

[Sid Squid]

You need to do a charging test.

Charge the battery and start the engine, with the lights on and the engine running at about 5000 rpm voltage at the battery terminals should be no less than 14.5V.

There's lots on here about this, (much of it written by me), see here: click me.