I will be replacing my two batteries next spring. I have a Perkins diesel in my OC281. I thought that I read somewhere that it was best to get matching batteries at the same time so that one is not stealing from the other. I also thought different batteries were best used for different purposes (starting battery with cold cranking power and house batteries for long slow drain. I usually have the batteries switched together when the engine is running or the shore power trickle charger is hooked up to keep them both charged and seperated at anchor or night sailing. If I have different types of batteries switched together will that effect the performance or longevity of either?