I'd hardly call a charger that puts out 12A a trickle charger. Most of these have no filtering. While this might not be a problem with tungsten lights, I wouldn't want to use it with no batteries with flourescents or electronic equipment.
I have a 55A Magnetek
that's only been used for about 7 months. If I could get $120 (shipped in the 49 states) for it, I'd pull it out sell it so I could put a fancier unit in there.
The literature says it's okay to run it on your appliances without a battery load being connected.