A full equalize charge can take up to 16 hours that's why it is called a "weekend" charge. But try that for two or more consecutive weekend and see if that helps. Secondly, all that sulfate you cleaned off the outside is a sign of improper charging, overfilling and loss of acid in the batteries electrolyte. Water should never be filled up to the bottom of the fill whole only just enough to cover the top of the cell plates. I would speculate that your battery is not delivering full voltage to your electrical & electronic devises, an under voltage condition WILL shorten the life of contactors, destroy motors and brushes, burn out control cards, etc. Secondly, what is the voltage & amp/hour rating of your battery (that info maybe stamped in the battery case, on a decal affixed to the battery case or stamped on an inner cell connector near the positive cable connection - if you can't find it you are SOL & the amp rating of your charger - this is should be on a nameplate on the charger case. The battery charger max output should be no more than + or - 5% of the AMP rating of the battery. Too big of a charger will "fry" your battery. Your battery should be properly evaluated by a professional battery supplier - don't try to do this on your own. This evaluation can take 3-5 days & you'll need to have a way to get the battery out of the lift or take the lift to the battery dealer.
You will have to spend some money to see if you battery is on life support - no way around it. And there are no miracle cures to rejuvinate a bad battery - some folks say there is but I say & others with a bit of gray hair say, it is nothing but "snake oil".
1hr...3hrs.... like was already said, it takes good batteries at least 6 to 8hrs to charge if they are fully discharged. If you start opportunity charging them they will develop a memory and the runtime will be greatly shortened. This will also effect the charge time and it will become shorter as well. Once the batteries get in this condition they basically are useless for any practical use in shift runtime. You will wind up getting stranded without a lift while it charges and your operator is standing around twiddling his thumbs waiting on it.
save youself some trouble and bite the bullet and get some batteries. yes it is a heavy expense but in the long run you will see it was the wiser choice.
Does your charger have an "equalize" botton on its panel, its possible that the cells are at different states of charge, its a hail mary from the sounds of things but batteries are expensive and you cant say you didnt try ,if it has one push it and walk away.
A light should come on to indicate "equalize". The battery needs to cycle fully (approx 8hrs, make sure your water levels are topped up).How do your battery cables look , any strange looking bulges under the insulation (especially the Pos. cable).
How long does it last with a 1 hour charge..... 35 minutes? :-) Sorry, I couldn't resist. At any rate, your battery has a major calamity. BTW a full charge takes about 8 hours. You could get a hydrometer and check the specific gravity of the acid in each cell to get an idea of how charged it is and if any cells have failed. Sounds like it does have at least one bad cell and you really shouldn't continue using it like that.