BTW, Sorasound used to sell Amazon TT’s. He may be a good reference for info and maybe a manual, assuming you do not have one. Good luck
An addendum: I too am having some issues with getting up to steady speed. Takes too long. But I have had this battery for only about 8 months. The controller was left unplugged for about 4 days which is a no no for SLA batteries. But I thought the controller/charger would pick it back up to full charge. Apparently it has not. Which brings me to the source of my last battery, Amazon (.com). Yes, it was much cheaper than batteries Plus, but maybe it did not have the care and/or a full charge when I bought it. So I'm going back to batteries plus. Double the price $50 vs $25. But maybe a longer life too. This is then shortest life span I've had for a battery even though it is a PowerSonic which is the recommended battery.
This is a problem with the Big Co. that sell everything. Who knows how old the battery was or how long it had been on the shelf and/or w/o proper charge. The SLA batteries are quite different and temperamental from my experience. So you may want to go to a dedicated battery sales place. just a thought.