Why is my Eaton UPS beeping?

I just received a new Eaton UPS (Eaton 3S 700). I plugged it to a wall socket and connected a small tower server, a switch and a router. They work fine.

My problem: the UPS is beeping continuously and the light is blinking green.

The manual has two relevant entries:

I am not sure what is the difference between "audio alarm beeps" and "audio alarm beeps continuously" (does "continuously" mean beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep and not continuously means beep-beep-beep-beep-... ?). I have the beep-beep-beep-beep-... version.

The first case is doubtful: this is a new electrical installation and all these devices were already powered from the outlet before (though a strip and not a UPS), and they worked fine.

The second case is doubtful as well: not only the devices are not particularly power-hungry, but I see in through the monitoring program that

root@srv ~# upsc eaton ups.load
14

This means a 14% load. The battery is charged at 91%.

While the UPS behaviour does not suggest it, I see that

root@srv ~# upsc eaton ups.alarm
Replace battery!

I do not know if this is a default setting or there is indeed a problem with the (brand new) battery. The manual says

I just received a new Eaton UPS (Eaton 3S 700).

Did you connect the battery inside? All UPS units ship with the battery disconnected for safety in shipping.

Read the Setup Documentation, connect the battery, plug it in and wait an hour or two for the initial charge to happen.