I am a short person (5'1", 154 cm) with tall ceilings (15 feet, 457 cm). I have an 8-foot ladder (244 cm). On this ceiling I have a smoke detector whose battery needs to be replaced. On this model, this involves unscrewing the case, removing the D battery from the slot, sliding a new one in (properly aligned, of course), then screwing the case back on. The case lid is attached to the ceiling by several electrical wires that connect to the building's central fire alarm system.
If I stand on the very top rung of the ladder (eg. the apex, the thing you're not supposed to stand on) I can reach the alarm case just barely with my finger tips if I stretch out my hands. But I can't get a good grip on the case to open it.
I can't get a bigger ladder. The 8 ft model barely fits in the elevator as it is. I would rather not rely on bringing taller people home just to change the smoke detectors -- so is there a way for me to change these batteries?