The short answer
Most stairlifts run on two 12 volt batteries that charge whenever the chair is parked on a charging point. They typically last a few years, and Which? says heavy use can mean replacing them every couple of years, at about £85 a pair or about £300 for lithium. A lift that beeps, slows down or stops part way is usually telling you the batteries are tired or not charging.
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Almost every modern home stairlift runs on batteries rather than directly from the mains. That is good news: it keeps working in a power cut, and the ride is smoother. But batteries wear out, and they are behind more stairlift breakdowns than anything else.
How the batteries work
A typical stairlift carries two 12 volt batteries in the chair or the drive unit. A small charger plugs into a normal socket near the stairs and sends a low voltage along the rail, or to contact points at each end. Whenever the chair is parked on a charging point, the batteries top up.
Because the motor draws from the batteries rather than the wall, the lift keeps working for a number of trips in a power cut. How many depends on the model, the length of the stairs and the user’s weight.
How long do stairlift batteries last?
There is no single answer. The main things that wear them out are:
- Number of trips. A lift used a dozen times a day wears its batteries faster than one used twice.
- Parking off charge. Leaving the chair part way up the stairs, or switched off at the wall, slowly drains them.
- Heat and cold. Outdoor lifts, and lifts in very cold or hot spots, are harder on batteries.
- Age. Even an unused battery loses capacity over time.
Which? notes that batteries may need replacing as often as every couple of years. Many families find a set lasts a little longer with light use and a lift that always parks on charge.
What replacement batteries cost
| Battery | Typical cost (Which?, 2026) | Notes |
|---|---|---|
| Standard pair (sealed lead acid) | About £85 | The most common type |
| Lithium | About £300 | Lighter, longer-lasting, fitted to some newer lifts |
| Fitting by an engineer | Labour, often about £70 an hour | Sometimes done during the annual service |
Some firms include battery replacement in a service contract or a rental agreement. Check before you pay separately.
If the user is chronically sick or disabled, HMRC allows parts and repairs for their stairlift to be zero-rated for VAT, so ask the engineer to apply the relief.
Warning signs to listen for
Most stairlifts warn you before the batteries fail. Look out for:
- Beeping when parked. Many lifts beep to say they are not charging. Check the charger is switched on at the wall and the chair is at a charging point.
- Slower journeys. Weak batteries often show as a sluggish ride, especially going up.
- Stopping part way. If the lift stops on the stairs and needs a rest before going on, the batteries are probably near the end.
- Fewer trips than usual before it needs to recharge.
- An error code on the display. Note it down for the engineer.
If the lift beeps or stops, check the simple things first: the switch at the wall, the key switch on the chair, the seat turned fully forward, and nothing blocking the rail. Our servicing page has a short checklist.
Can I replace the batteries myself?
Some makers sell replacement packs for owners, but we suggest leaving it to an engineer. The batteries are heavy, they sit inside covers that need to be removed and refitted correctly, and the wiring has to go back the right way round. A mistake can damage the control board, which costs far more than the batteries. Old batteries also need proper disposal: lead acid batteries are hazardous waste and must not go in the household bin.
How to make batteries last longer
- Always send the chair back to a charging point after use, top or bottom, whichever your lift charges at.
- Leave the charger switched on at the wall. Put a label on the socket so nobody turns it off by mistake.
- Do not use the key to turn the lift off for long periods unless the instructions say so.
- Book the annual service. The engineer load-tests the batteries and can tell you when they are getting tired, before they let you down.
- Mention long absences. If the user is going into hospital for a while, ask the engineer how best to leave the lift.
Electricity costs
Charging a stairlift uses very little electricity. The charger draws only a small current, and the batteries take a top-up after each trip. For most homes the cost is a small part of the yearly bill. It is the batteries themselves, and the annual service, that make up the real running cost.
When it is more than the batteries
New batteries fix most beeping and slow running. If a new set does not help, the fault may be the charger, the charging contacts on the rail, or the control board, which needs an engineer. If a lift is old and needs a costly part, it can be worth comparing the repair with a reconditioned straight stairlift.
If you need an engineer, or are thinking about a new lift, tell us about the stairs and we will find someone who covers your area.