what to look for on a battary charger

[blau]

I don't drive my cars often. I had one dead battary already due to discharging battery (had the car system checked nothing wrong except not driving enough). I am looking for a battary charger. I was told that I should look for a trickle charger. How could I tell it is a trickle charger? If it said it is a 1.2 Amp does that make it a trickle charger? What else should I look for? Is it important that I get one or a brand known for its quality (ie more expensive) or is it like windshield washer fluid (ie does not matter that much).

thanks

blau.