battery time

We run an optima yellow top on a 440. It holds charge fine for down periods of a month at a time, but acts like a typical deep cycle, or agm, if its fairly discharged, it takes a very long time to recharge and prefers a slow charge. It does not respond well to charging by a 30 minute drive in the car.
A while back we discharged it to about 7 volts as I left the key in acc for three days, which is not a good idea, nor good for the battery, would not accept a quick charge with a 30 minute drive (100a alternator). We did the same as instructed above after bitching to optima about their battery, they gave us the directions over the phone and it worked perfectly. Jumped it to a charged battery for like 6 hours, then trickle charged it on a 5a smart charger for 24 hours which it must have taken 20 hours to fully charge. I took it off charge and put it back on that evening, it charged for another 6 hours before it completed again. Freaking deep cycles, deep charge, deep discharge, not really optimum for an automotive battery. Should have got the red top but the fans and wires are yellow. I think the red is most recommended for automotive due to quick discharge volume.