The battery size and amps depends on the engine size and the trim level (such as DX, EX, LX). And I don't think it would be very smart to buy a car battery online and have it shipped because of the shipping weight. The cost of shipping a 50 lb battery would cost nearly as much as the battery. But you can buy it online and then pick it up at the store, for example, buying it online at the AutoZone website and then picking it up at your local AutoZone store. I have always had very good luck with the AutoZone Duralast batteries. I have used a number of different battery brands over the years and I used to prefer the Sears DieHard brand but it seems, in my opinion, that the quality of the Sears DieHard batteries has turned to crap over the past decade or so. But in my experience I have found the AutoZone Duralast batteries as good as any brand I have ever used and better than most. And if you are satisfied with the service you got out of your original OEM Honda battery you might also consider a Genuine Honda battery. They are sold at your local Honda dealership parts department and although the prices are slightly higher than some aftermarket batteries you will still find them to be priced fairly competitively.