A faulty battery led to a back-up generator failing to kick in when a hospital lost power during a UK-wide power outage, it has been revealed.
When two power stations became disconnected from the National Grid last Friday, power was cut to places including Ipswich Hospital because of the loss of power nationally.
The hospital generator should have been turned on by a battery-powered switch.
The battery, despite being tested a few days before, failed.
The power loss affected outpatients, X-rays, scans and pathology for nearly half an hour, but the hospital stressed no patients were put at risk.
Ipswich Hospital Trust managing director Neill Moloney said: "It was only a few days before that we tested the battery and it was working.
"So it came as a bit of a surprise. We were really happy with the way in which the staff responded."
Power failures were reported across large areas of the UK on Friday, affecting homes and transport networks.
BBC journalist Vikki Irwin told how her mother was on a scanner's hydraulic lift at the time.
She said: "They said the power had gone out across the site.
"Lots of parts of the hospital were completely dark. We had to get my mum down manually."