I use the harbor freight special, and honestly i really like it. I like that it gives you an actual voltage readout. Mine is hooked up 24/7 to my other car
https://www.harborfreight.com/4-amp...ntrolled-battery-chargermaintainer-63350.html
https://www.harborfreight.com/4-amp...ntrolled-battery-chargermaintainer-63350.html