Before you buy Optimas check out the Trojan. They are a little cheaper and in my opinion a better battery. I had Optimas and they were good bats, but didnt seem to hold a charge as long as the trojans do. Both of them charge really fast. Much faster that the acid bats. After a day on the water, it takes an hour to 1-1/2 hours to full charge. No fumes and you dont have to worry about water or battery acid. There are other advantages to using them. I wouldnt mix the two different types together, but I really dont know a reason not too. Maybe someone else can jump in and give you more info.Martin
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