The control box on my elederly parent's stairlift started beeping
every three seconds. Does anyone know what this means? I opened the
box thinking that the PP3 battery inside might be running down, but
the beeping continued after I replaced it.

I wonder if the beeping is a warning that the main gel-cell battery
powering the motor is on its way out. Anyone know? The gel-cell is a
bit of a pain to get at, otherwise I'd just test it with my
multi-meter rather than posting this question. The gel-cell bettery
has not been changed for about ten years, I believe. It is supposed to
keep itself charged up from the mains while the stairlift's chair is
stationary.

Thank you..

JD