I have a Viking 4 amp smart charger for multiple types of batteries with float charge too ..It also comes with a pigtail to hook to the battery that you can use to quickly connect and disconnect the charger...Its the fastest and easiest fix for your question...
I keep mine under the hood hooked to my batteries in vehicles that sit alot and for those I use the 1.25 amp Battery tender float chargers by Deltran and I also have a couple from Harbor freight too for my scooters and motorcycles..
Amazing deals on this 4Amp 12V High Freq Battery Charger/Maintainer at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
Good Luck