Smoke alarms in rental properties

[WearyLady]

Do these have to be wired or are battery operated smoke alarms acceptable in rental properties?

I had battery ones (Fire angel ones where you can't take out the battery, but it's not wired). My landlord & letting agents pretty good on the box ticking stuff, so I am fairly certain they would have been within regulations. (I only left this year so don't think anything will have changed since either)

My landlord has just installed a new one for me, along with a fire blanket and extinguisher. It apparently has a 10 year battery so I'm assuming that it meets regulations.

Thanks to you both.

It varies depending on size and location of property. HMOs usually need wired, for example.

I have none I have to ring and get them in as my landlord couldn’t be bothered to put them in. He also tampered with the electrics and I had faulty electrics for the first few months of my tenancy agreement