If that is a lead/antimony type battery commonly used for such applications, it may have a noticable amount of self discharge as well, which would need to be made up to bring it up to full charge each day in addition to what you use. I would figure up to 2% of rated capacity, or about 24 Amp Hours per day, or about 10% of your stated usage - although this will vary with the type, the condition of your battery, and the temperature. Rich