What is the best way to properly maintain a maintenance free car battery'

I've got a bad experience with deep cycle lead acid batteries I bought a expensive well known brand but the battery was dead just a while after it's warantee expired.
now I might be partly to blame as I did not maintain it with a trickle charger. I did however charged it as soon as possible after using it.
My question: Will a normal lead acid car battery be able to last just as long as a deep cycle battery if maintained the same, with both being used maybe 20 times a year during power failures etc?
What is the best way to properly maintain a ''maintenance free car battery'' used in the way I described? Can you leave a car battery on a trickle charger indefinately without any ill effects?
Well, if you're discharging things down quite a bit, you'll want what DCs have to offer. Car batteries are good for short bursts of current, over shorter periods of time--cold cranking amps, but they don't like being discharged down to say 50% and then charged back up for X amount of cycles, from what I've read.
My research shows 2-5 years for SLA/AGM batteries, which is kind of what we get out of our car batteries.
I bought a little SLA/AGM (12Ah) for my solar kit and I'll just hit it with some juice and top it off every 2-3 months.
You can spend $40 on 3 stage SLA/AGM charger and go that route. Take the AGM battery out and use it here and there, to prevent sulfation.