UPS APC Back-UPS ES 700 - endless squeak after turning on. How to be?

Question

Uninterruptable power source

UPS APC Back-UPS ES 700 when turned on:
briefly beeped (this is normal),
"thought" ~ 5 seconds, while the green light blinks (also as usual),
then the light should burn stably, showing readiness for work, but instead this, it continues to flash + 4 squeaks for 0.5 sec.,
another 5 sec. blinking,
and the light turned off + a continuous squeak that does not stop until you turn off the UPS.
The manual says,
"Overload Shutdown - An overload was detected on one of the battery-powered outputs while operating in Battery Mode."
It is possible to start if you remove all the plugs, turn on the UPS, insert the plugs back.
Also, if you rearrange the plugs from "sockets from the battery" to "sockets without a battery (only with surge protection)" - there will be no problem
(then the UPS can not be turned on at all, because "sockets without a battery" work in off state).
Has anyone experienced this?
Will replacing the battery help, or is it, on the contrary, useless?

Answer 1

Yes, a replacement should help, but I would check the battery

Answer 2

The battery has served its purpose - it was on another UPS, it did not start with the load connected. Replacing the battery should help.