Thank you all for your comments and good advice. You have guessed correctly - the sun logo indeed. Since posting my question I have phoned at least 10 motor factors and none can provide a print out, though several could provide a drop test. After reading Tony's response though, I am thankful at the moment that I have not gone ahead with it. Last week I found an extremely helpful guy at S&J Motorfactors in Bradford (tel 01274723027) - if anyone needs a motor spares shop in the area - he’s your man.
On seeing the battery and hearing our tale of woe he did me a test (not a drop test) with a print-out showing Volts 11.70 measured 143a EN Rating 500A EN (if this means anything to you very knowledgeable folk?). He then took the battery for a couple of days, and deep-charged it, giving me a final read-out of Volts 14.09 measured 230A EN Rating 500A EN. He suggested I try the battery again, gave us loads of advice and was genuinely concerned and helpful about the problem. What a lovely helpful fellow he was, and insisted he didn't want any money for his trouble - though I managed to make him take a contribution to the tea-fund box eventually. We've re-connected it with the other one and have used them for the few days. Getting a bit more power, certainly not up to what I’d expect - though I’m wondering if in my ignorance I’m expecting too much.
So, we're back to 2 x 220 Ah deep cycle carbon fibre batteries, bought in Aug 2008 which we use with our MasterVolt 12/2500-100 Inverter and charger (12v system). We’re a widebeam with a 62 hp beta marine engine. We have a separate starter battery. We had a service with the RCR in May 11 and they told us the 95 amp alternator was charging correctly. Although we live aboard and during the winter use shore power, during the summer when out on the system I think we are fairly low consumers. Small tv 30 mins a day, a few LEDs - not on much at moment, a 12v fridge. Maybe not (wearing my tin-hat here in case I get a blast from you all). After reading various pieces of advice here on Canal World, I will do a power audit and I have bought a multi-meter (not tried it yet, looks a bit daunting). We have always had to run the engine 2 x per day, for 1-2 hours approx each time - even when the batteries were new - a bit more if using the laptop or TV, but we run the engine at the same time. On travelling days - though we only do 4 hours or so generally, we tend to get enough charge into the batteries without having to do extra charging. I know we will never get the batteries fully charged just running the engine, and I know with the sulphation problem we had we probably have poor battery, but any comments anyone? Are we using too many appliances? Not running the engine long enough? Or just expecting too much from very expensive batteries that have an unworkable 5-year ‘guarantee’?
Anyway, back to those people with the sun logo - last week I emailed them and asked where I could get a digital drop test with a print out - before I read Tony's comments. Unsurprisingly I have had no response - I shall for the moment pursue the warranty (knowing full well really, that it's not worth the paper it's written on). I'm pretty sure they will say it's mis-use, and I can't prove otherwise of course. I have always followed all their do’s and don’ts and have read all their FAQs (see their website). Hopefully discussing these sun logo people on this forum, might dissuade others from buying from them. I’ve not seen any ads in Canal World or Waterways World for them for ages, though the Caravan Club continues to ‘endorse’ them. I have emailed those not very sunny people twice in the last few days, and got no reply. Beware I say!
Thank you again for all your efforts and information - though reading your comments and advice, I’d better understand a bit more about usage and maintenance of the batteries before I plunge for a set of new ones! ps- is it better to get 4 x 110's or 3 x 130's or large ah's or does it all depend on space available or cost? Showing my ignorance again!!