I have group 27 Northstar CCA 930, MCA 1165, Warm cranking amps 1430. 91AH capacity These batteries are heavy that is my only complaint. The group 31 CCA 1150, MCA 1370, warm cranking amps 1770, 103 ah capacity. The group 31 is 75lbs. They advertise " Cycles over 900 times to 50% depth of discharge",Faster recharge,. The marina that I worked at a number of years ago used only Optima Batteries. The service department/marina was 80% turn key customers. We did all maintenance on these boats. The Optima service was good. They started using NorthStar as a backup to Optima when there were back orders. They switched over 100% to Northstar 4 years ago because they felt the service time was better. I had a hard time pulling the trigger on the NorthStar because of price and weight. I did and on my second season, no issues yet. The Jury is still out for me. I can give a better review in 3 more years if the batteries are still in service. We did anchor 2.5 days 2 nights at an anchorage in Georgian Bay and maintained battery power. I do not have solar or generator. I used my inverter for coffee, microwave, 12v for lights, refrigerator, C pap at night, head, and water pump, charge electronics, The Thruster battery paralleled to house while at anchor. I did do a charge once for half hour with main engine to charge batteries and heat up hot water tank. The batteries were at just over 12V when we pulled anchor. It was not long after we left the anchorage I was seeing over 13V+ at the battery monitor for house, thruster, and engine and with-in an hour showing high 13V numbers. My only complaint is the weight. The original maintenance free that came with the boat lasted 3 seasons weighed 43lbs ea. I would not have been able to anchor 2 days and 2nights. I know because we anchored at 3pm in the afternoon and by morning the batteries were at 11.8V and the inverter alarmed and shut off at anchorage on the Mississippi River. With the additional weight of theses batteries stored aft I lost 1.5 kts in performance. The C26 is very stern weight sensitive. NorthStar Group27 67 lbs, Group 31 75 lbs. The Group 27 added almost 100lbs more weight to the aft. Good capacity comes with weight. I would recommend the NorthStar so far.
