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ABUS RWM150 or Prefira

Updated: 20 October 2026

You already want ABUS, and the basket is stuck between the RWM150 you have seen for years and the newer Prefira alarms. The RWM150 listing promises a sealed cell for up to 10 years. The amazon.co.uk reviews, 3.7 from 1,421 of them, mostly say that cell gave up early. This page says when the RWM150 still makes sense, when the Prefira Slim is the closer sealed buy, and when you should leave both for a Prefira you can open. Prices are the 19 October 2026 amazon.co.uk captures: about £20.23, about £23.65, about £11.28 and about £52.17. A qualifying purchase can earn a commission at no extra cost to you. Model cards are on the [ABUS smoke alarm comparison](/hub/fire-protection/abus-smoke-alarm).

You already want ABUS, and the basket is stuck between the RWM150 you have seen for years and the newer Prefira alarms. The RWM150 listing promises a sealed cell for up to 10 years.

Our top picks

ABUS ABUS Prefira 5

Best overall

ABUS ABUS Prefira 5
8.8/10about £11.28
View offer
ABUS ABUS Prefira Slim

Rank 2

ABUS ABUS Prefira Slim
8.4/10about £23.65
View offer
ABUS ABUS RWM150

Alternative

ABUS ABUS RWM150
7.4/10about £20.23
View offer
On this page
  1. 1.What the RWM150 listing promises
  2. 2.What the reviews actually repeat
  3. 3.When a Prefira is the clearer buy
  4. 4.A conditional recommendation

What the RWM150 listing promises

The RWM150 is the optical alarm in this set. The amazon listing describes a permanently installed 3 V lithium battery, a life of up to 10 years, an 85 dB tone, and a sensor that reacts to visible smoke particles. It cites EN 14604 and VdS 3131. ABUS’s own UK page repeats a hush of about nine minutes. The captured amazon bullets do not confirm that hush button, so treat nine minutes as the manufacturer sentence.

What the reviews actually repeat

Across the first 50 amazon.co.uk reviews, the story that keeps returning is a sealed cell that failed inside the advertised life. People name about 10 months, and about 1.5, 2, 3, 3.5 and 4 years. It is honest to say early failure is the dominant theme, which is why the rating is 3.7 from 1,421 reviews rather than a small angry sample. You cannot fit a replacement cell. When an RWM150 chirps, often described as a beep every 40 seconds, the remedy on a sealed alarm is a new alarm, not a trip to the battery drawer. The German grade does not answer that chirp.
ABUS ABUS Prefira 5

Testsieger

ABUS ABUS Prefira 5
8.8/10about £11.28
View offer

When a Prefira is the clearer buy

The Prefira Slim, model 36395, is about £23.65 and 4.2 from 26 reviews. The listing claims a sealed battery for up to 10 years, EN 14604, a Q-Label, and an LED that dims in the dark. The box includes an adhesive pad and a magnet as well as screws. That mount is a practical difference from the RWM150 listing, which does not itemise a pad. Twenty-six reviews is not a 10-year test. You are buying a newer sealed shape with a short UK file, not a proven replacement for every RWM150 that died at three years. The Prefira 5, model 35552, is the branch where you want to change the battery yourself. It is about £11.28, 4.4 from 78 reviews, with replaceable cells rated up to five years. It does not fix the RWM150 by being sealed. It fixes the problem of a cell you cannot change by not being sealed. The Prefira Smart does not fix the sealed-cell problem either. A phone alert is not interlink.

A conditional recommendation

Buy the RWM150 only if you have read the early-battery reviews, you accept a 3.7 rating, and you still want this sealed housing at about £20.23. Do not buy it for the 2021 German grade, for a hush button the amazon bullets do not confirm, or because 40 square metres was printed on the manufacturer page. Buy the Prefira Slim if you want a sealed ABUS cell, a dimming LED and a magnetic mount, at about £23.65, and you accept that 26 reviews cannot show a decade. The best ABUS smoke alarm page uses that same criterion for the top pick. Buy the Prefira 5 if you will swap AAA cells and you want the lowest price in the set. None of the four interlinks with the others. Fitting any of them still means a ceiling in the hall, about 30 cm from walls and lights, which is the how to fit an ABUS smoke alarm page.

Common questions

Should I still buy the RWM150?
Only after you have read the battery reviews and you still want a sealed unit you cannot open, at about £20.23. The listing claims up to 10 years. The first 50 reviews describe failures from about 10 months to about four years, and the star line is 3.7 from 1,421 reviews. If that pattern is why you are hesitating, choose a Prefira instead of hoping this batch is the exception.
Is the Prefira Slim the replacement for it?
It is the closest sealed Prefira in this set: a 10-year claim, EN 14604, a Q-Label claim, and a pad and magnet. It is not a like-for-like proof that the cell will outlast the RWM150, because the Slim has 26 reviews and no 10-year ownership record. Budget about £23.65 and treat the short file as part of the decision, not a footnote.
What if I want to change the battery myself?
Choose the Prefira 5. ABUS describes two replaceable AAA cells with a life of up to five years, at about £11.28 on the capture we used. The Smart is also replaceable, at about £52.17, and it still needs a Thread Border Router. The RWM150 and the Slim are sealed. A dead cell on those two means a new alarm.
Does the Smart alarm fix the sealed-cell problem?
No. The Prefira Smart uses a replaceable battery rated up to five years. It adds phone alerts over Matter on Thread if you already have a border router. It does not give you a sealed 10-year cell, and it does not make other smoke alarms in the house sound. Six reviews are too few to treat 4.6 as a durability result.
What do I do when an RWM150 chirps every 40 seconds?
Treat that as a failing sealed cell, not as a fire, once you are sure there is no smoke. You cannot fit a new battery. Replace the alarm, and do not leave it chirping until a 10-year date on the box. If you cannot tell a fault chirp from a full alarm, get out and call 999.

Related pages

ABUS smoke alarm buying guide

ABUS smoke alarm

Best ABUS smoke alarm: a sealed pick and best value

How to fit an ABUS smoke alarm: ceiling, test, replace

Landlord smoke alarm rules across the four UK nations

Sources

Public UK sources from the research digest. Listing prices, stars and review counts are the amazon.co.uk lines captured on 19 October 2026.

  1. GOV.UK — Smoke and carbon monoxide alarm regulations, landlord booklet (retrieved 19 October 2026)
  2. GOV.UK — Approved Document B fire safety FAQ (retrieved 19 October 2026)
  3. Scottish Government — Tolerable standard, fire and carbon monoxide detection (retrieved 19 October 2026)
  4. Scottish Fire and Rescue Service — Smoke and heat alarms (retrieved 19 October 2026)
  5. legislation.gov.uk — Wales, The Renting Homes (Fitness for Human Habitation) (Wales) Regulations 2022 (retrieved 19 October 2026)
  6. legislation.gov.uk — Northern Ireland private tenancies regulations 2024 (retrieved 19 October 2026)
  7. Fire Kills — Detection (retrieved 19 October 2026)
  8. ABUS UK — RWM150 smoke alarm (retrieved 19 October 2026)