Re: Optima Start Batteries Blue vs Yellow vs. Red "Top"
Reply #7 –
FWIW, I read somewhere, but cannot find it now, that if an Optima battery has a black case it is a "starting battery". The red tops have a black case and the other colors are gray. I have red tops for the engine or chassis battery and MK for the house. After both have been fully charged and allowed to sit for 24 hours with everything off, the Optima is about .5 volt less than the MK. MK stabilizes at about 12.75 and the Optima at about 12.25, not sure why that is unless it is just different batteries. No problems with starting, or anything else electrical. All of my batteries are about the same age. Since the chassis battery is primarily only used for starting, seems like a starting battery should be used for that.