Thanks for responses and feedback......much appreciated. I am rapidly coming to the conclusion that the 7.0 is probably overkill as you say Ray. I will look for something of lower capacity that does not click!

I think I used a CTEX MXS 5.0 in my van. Like Ray, a wet lead acid battery, though mine I think is about 80 amp hour... No clicks!

The CTek 7.0 works fine without clicking on a 75amp lead acid battery fitted to my boat but clicks like mad on the 100amp AGM I’m my Eriba.

Niv2, it would be useful to get a comment from somebody with a 100Ah AGM battery and a smaller capacity CTek charger, just to try and identify if it is the charger or the battery that are the problem here.
Shame that CTek aren't as helpful as they could be.

Thanks for all your help. I have decided to move away fro CTek and have acquired a Mastervolt Easycharge Fixed 6v largely as they were selling these for a good price at my local yacht chandlery and they seem like a solid piece of kit being well built and waterproof. It is very simple, being simply plug and play, so hopefully nothing to go wrong. It is also completely silent.
I did eventually get a reply from CTek and they told me that the regular clicking was normal (I sent them a video).....

That looks like a good fix,I'm thinking of doing something to bypass the existing charger. The manual seems unclear what the single pole switch is mean to be for, can you confirm what it did on your unit? ours doesn't seem to do much at all!
Happy new year!
Julian

Southbourners,
I believe that the single pole switch is to switch 12Vdc from the towing vehicle to the caravan without the tow vehicle engine running.
Something I used to do many years ago before leisure batteries were the norm and I could run a couple of 12Vdc lights from the tow car's battery.

Not used much or ever today so I used it as described to get power from the Ctek in to the BIP.

Great stuff, that makes perfect sense.,
Thanks,
Julian
2008 Triton, with petrol auto Ateca 1.5.