1 amp is perfectly fine for maintenance charging. The best is to get a standard
10amp charger PLUS a 1amp to balance things out. I use an Ampere Damper
which simply drops the 10 amp charging system down to .5 amp and 1 amp
(switchable). This allows me to handle the big jobs, eg when I leave the lights
on, fast charge (the 10amp charger has 50amp boost) as well as the safer
trickle / maintenance charge.

Neither the car's charging system, nor the 1amp chargers were designed to
restore depleted charge of the battery. To do that, you should use charger
which is 10% of the total amperage of the battery. Usually 10amp charger
will do the trick most of the time w/o fear of overheating or overcharging.

__________________
-- raymond~
47º 34'N 122º 18'W