Home lift battery and backup issues in the UK

UK domestic lifts installed under the Machinery Directive are required to have a means of safely evacuating a passenger if the mains supply fails. On cabin lifts (Stannah Ascend, Cibes, Aritco, Terry) and most through-floor lifts, this is a battery-lowering pack that engages automatically on power loss. It typically has enough charge for one full descent from top floor to bottom, plus a door opening — no more.

This is why the pack is small (two 12 V sealed lead-acid cells is typical) and why the lift will not run repeatedly on battery alone; that is not what it is for.

After the battery has completed an emergency descent, the controller locks the lift out of normal service until the pack has recharged to a safe reserve. On most UK home lifts this takes 2–6 hours. Symptoms during the recharge:

• Display shows a battery icon or a code beginning BAT.
• Call buttons are unresponsive or respond with a short beep and no motion.
• The car sits at whichever landing it lowered to.

UK home-lift batteries last 4–7 years in normal service, less if the lift lives in a garage or unheated shaft. Warning signs the pack is at end of life:

• The lift refuses to run for hours after even a brief mains blip.
• The battery symbol appears when nothing else has happened.
• The car makes only part of a descent before the doors won't cycle.
• The annual service report notes the battery voltage under load has fallen below spec.

Replacement is a routine service item. On most UK lifts it takes 20–30 minutes and one of the batteries the service provider carries as van stock.

Almost always on. Modern UK home-lift controllers trickle-charge the pack from mains and manage battery health via the same circuit. Isolating the lift for weeks means the pack self-discharges, sulphates and — if left long enough — will not recover a full charge even after re-energising.

The exception is a house left unheated in a hard winter with the shaft below freezing; even then, ask the service provider whether they recommend isolating or leaving on for your specific installation.

No. The battery is a safety component. On UK lifts, replacement must be by a competent engineer and, for LOLER-notifiable installations, must be recorded on the lift's history. DIY replacement will void the service contract and, if the wrong battery type or capacity is fitted, can cause the battery-lowering system to fail exactly when it is needed. It is a service-visit job, not a DIY job.

A few UK home-lift setups have specific quirks worth knowing:

• Solar / battery-storage integration. If your house has a home battery, ensure the lift's dedicated spur is on the ‘essential loads’ side of the switchover — otherwise the lift may lose mains during a grid fault and needlessly discharge its own pack.
• Air-source heat pumps. Very large loads switching on the same phase as the lift can cause a brief voltage dip that trips the lift's under-voltage sense; if this happens repeatedly, an electrician can measure it in an afternoon.
• Generator supplies. Some older generators put out a poor waveform that home-lift controllers refuse to run on. If the lift works on grid but not on generator, that is why.