Many thanks Steve for clarifying this for the benefit of others.
Hello Tony,
I’m not sure what you now want to believe, but you have a battery of dubious origins, and I believe until you replace it with a reputable branded one, and get it coded to the car, you stand little chance of getting anywhere with this, but it must be your choice. From my side, and apologies if this appears critical, but you seem to be bombarding us with unnecessary detail.
Anyway, back to your battery and charging check:-
A couple of observations - the charging voltage measured at 13.8v at best, is below par, and I would be expecting around 14.5 volts.
I’m not sure what he told you about CCA measurements, but surely Cold Cranking Current would be measured in what it is - amps. not volts.
If you are going to decide on fitting a reputable branded battery, you won’t go far wrong with a correct-for-car Exide from Tayna Batteries. Give them your reg. no., and they will advise on the correct one.
You will need to further investigate the alternator output.