That is true however, take care of the battery yourself. I had an idiot take a look at the Battery liquid when it was giving some problems and he spilled a few drops of acid outside the bonnet on the car. The color went yellow right away on 1-2 inch spot... I went the same day and changed out to a Dry Battery.
Anyone maintaining a Wet Battery should have that device + check it once a month yourself. Or even if you have the so called "ustaads" check, then have them hold a rag so no spills take place.