You can pick up a battery charger at Walmart for $50 (Schumacher). It does a trickle charge until the battery is full. Since you do not take the car out too long during the week the maintener will keep amperage up on your battery. You only have to do this maybe once a week. A lot of exotic car owners do this as we have phantom drains on our batteries. Very safe for the car and extends the longevity of the battery.
http://www.walmart.ca/en/ip/6-4-2-am...H%3Aschumacher