Any/all of the batts, except AGM style, have "covers" that can be pried up with
a screw driver for visual check...I looked at my replacement before I put it in;
it was fine. Level? A little above the plates. Try an large eye dropper or squeeze bulb with plastic tube as opposed to "pouring" any water in..,Yes, distilled water.
Worth a check in very hot conditions, though it is not handy to get to.
GL,mD