Thank you Tony. I will admit to having little, actually read no real knowledge, of the science of batteries etc which is why the request for someone to review my system to ascertain whether it's just the battery or an uderlying fault. The marina state they are unable to get to it until well into May . Couple of emails and leavi g phone messages. 24 hours charging still only 9 odd volts. So bit the bullet and bought a new battery. Engine now turns over with ease. Will await further contacts to ascertain if I've a problem with the wiring set up. All good for now though.