2summers

I have a 40' Monaco Windsor and need new house batteries. The batteries that are in the motor coach now are 6 volt Interstate Battery U2200's. What brand would everyone recommend for performance and reliability? The batteries that are in now have what looks like a bulge on top where the positive anode post is but the negative looks flat on the top of the battery. Does anyone know if this is normal? Any and all responses will be greatly appreciated. Thanks Mark