My electricity supply at home is being squirrely. The power company are installing a voltage recorder today, but they'll not do anything until they've monitored the situation for a while.

I've currently got an APC UPS, but I've stopped using it because it keeps clicking (when the relays switch to battery) and beeping (when the power does drop out for too long). This is annoying. Is there any way I can switch it to always run from the battery, as a laptop does?