Those are not surge protectors, but uninterruptible power supplies- most of which will have a surge protection circuit, mind.
Edit: for comparison, this is a UPS:
It weighs 5 pounds, and is about the size of a shoe box. The batteries don’t provide surge protection- instead those use a circuit to effectively trickle charge and maintain the battery. If normal power is lost, that circuit flips over to discharging the battery.
Ah I was aware they made surge protectors without battery backup, but I wrongly thought they were both just ‘surge protectors’ and wondered if OP somehow left out that his had a battery backup.
Those are not surge protectors, but uninterruptible power supplies- most of which will have a surge protection circuit, mind.
Edit: for comparison, this is a UPS:
It weighs 5 pounds, and is about the size of a shoe box. The batteries don’t provide surge protection- instead those use a circuit to effectively trickle charge and maintain the battery. If normal power is lost, that circuit flips over to discharging the battery.
Ah I was aware they made surge protectors without battery backup, but I wrongly thought they were both just ‘surge protectors’ and wondered if OP somehow left out that his had a battery backup.