SU2200RM3U will not switch to batter power.

[Anonymous user]

This unit will not power anything from the batteries. The batteries all have 13V on them out of circuit and appear to be fine. when I press the power button to switch to battery power, whatever is plugged in just goes dead. If I hit the power button with the UPS unplugged from the wall, it comes on lights up and beaps etc, but never sends any power to the outlets even though the batteries appear good. There are two resistors on the board that were toasted up, but still measure good. All the fuses are good.

What components have gone bad??

[BillP]

"Is it possible the batteries are bad even though they all measure 13 volts?"

As I explained in the other thread you posted in... Yes.

Also, pressing the button on the front doesn't force it to switch to battery, unless you're pressing & holding the "test" button for 3-4 seconds. Is that what you mean?

[Anonymous user]

Check voltage on battery under load. If they collapse, they're dead. Bad battery will act like a clogged plumbing.

Normal pressure with the faucets closed. Sudden collapse in pressure as soon as something is opened due to inadequate flow.

[Anonymous user · Accepted solution]

This unit will not power anything from the batteries. The batteries all have 13V on them out of circuit and appear to be fine. when I press the power button to switch to battery power, whatever is plugged in just goes dead. If I hit the power button with the UPS unplugged from the wall, it comes on lights up and beaps etc, but never sends any power to the outlets even though the batteries appear good. There are two resistors on the board that were toasted up, but still measure good. All the fuses are good.

What components have gone bad??