A quality battery maintenance charger will work just fine. Not simply a trickle charger, they charge as needed to maintain battery voltage. Be sure to buy a good quality one, you definitely get what you pay for.
Physics Major and Philosophy Major, Portland State University
ASE Certified Master Auto/Master Truck Technician
Fleet Service Northwest, Hubbard, OR
"If you can't explain it simply, you don't understand it well enough." - Albert Einstein