So, my landlord is threatening to charge me and my housemates the cost of fixing some smoke alarms.

Basically they all started going off a while ago, no doubt because the batteries were low, so we disconnected the ones we could. But others were hard to disconnect so we ended up cutting the wires to the mains because the other option was GOING MENTAL FROM THE ANNOYINGNESS.

I realise now that this was illegal. But do landlords not have some legal responsibility to check the batteries on smoke alarms are ok? There's nothing in the tenancy agreement, but am looking for some way to counter the threats with 'errr, actually it's your fault'.