Hi Mark, have to say I'm surprised you have had no issues with them and 13v after 6 months is remarkable, presumably the bike was kept in a heated garage? My experience with two others who have gone through 5 of them in about 8 years is the opposite. Poor terminals, one that burst, one that had the case open up, variable build quality and none of them made it past 30 months. The low CCA issue didn't help, and the misselling by many sellers on ebay claiming them to be gel batteries (AGM use liquid acid) should raise concerns about what they allow as marketing information to sell the product. If you add the often premium price over the better quality ones they don't really make sense on a V twin. I hope your luck with them continues.
M&P replied, “the actual requirement for your bike is 160CCA, so the battery we sent you is correct at 175CCA”, I have responded with a photo showing them they sent 150CCA
After much emailing including sending photos of the 150CCA battery with 150CCA stamped on it’s side M&P could not get it into their heads that this was the battery they sent , so I gave up and accepted a refund, never had a problem with M&P before so I’ll regard it as a one off