This was my third APC battery backup. After buying two APC 350s and being very happy with them, I decided to buy an upgraded model. I was very shocked reading some of the reviews. I have none had any "noise" issues with any of mine. All of my are and have been silent. For safety reasons, you must connect the battery. I found this very simple and will only take a minute. You then must allow the batteries to charge. The unit can be used during this time. The software is simple, yet provides a great status readout and several options. I use the 725 as well as 350 for my computer systsem. I use my 725 for my most important equipment and get around 10-15 minutes depending on what I have pluged in. The APC support is very good. One of the best business like support for the home I've seen in the computer business. APC as a company feels very professional and secure. I have not a single bad thing to say about the 725 or its similar models and recommend one to all.

I purchased one of these from Dell and have used it since Christmas. It's dead quiet and perfectly reliable. From what I read here, the noise issue is a known problem with SOME units, and will be corrected by APC upon request. I just bought another one and will be trying it out tonight. Yes, it's heavy (DUH)... it has a big heavy battery in it, that's how it works. Took me less than a minute to open my first one, connect the battery, and close it up. Maybe the person who had trouble was trying to hold it in one hand and connect it with the other, otherwise I can't imagine why he had trouble. And yes, you have to charge the battery fully before the first use (DUH again). My only complaint is the plug layout. Some plugs are UPS and some are surge only. I would prefer that they ALL be UPS and it be on my head if I overload it and have low backup time (I have several minimal drain devices (LinkSys routers, etc.) that I mainly want to not have to reset after "blinks"). Also, the power off button ONLY controls the UPS plugs, NOT the surge only plugs... so half of it's kind of like a surge protected power strip WITHOUT a switch... still scratching my head about that one (the only way to power off the surge only devices is to unplug them from the unit). Anyway, I like it. I'll let you know if the second one is a turkey and what hoops (if any) I have to jump through with it. Right now I recommend this product highly.

I purchased four (4) BE725BB units. With one of the units, I experienced the "noise" issue described in some of the above posts. A quick search of the APC Knowledge Base revealed the following:

"Answer ID 6942-Hissing sounds coming from the BE725BB.
Question:
Why is there a strange hissing sound coming from my BE725BB?
Answer:
The reason for the hissing is linked to a part in the unit that has a non-dangerous irregularity. This is a purely cosmetic issue and is in no way dangerous, nor will it impede the process of keeping your equipment up during a power disturbance. If you have one of these and would like it replaced with a non-hissing unit please contact e-mail support via our support page [http://www.apc.com/support/index.cfm]. You will need to include your model and serial number in the e-mail."

I followed instructions and APC promptly sent a replacement unit along with a pre-paid shipping label with which to return the defective unit. Note that you will need your receipt to expedite the exchange process.

As with the previous reviewer, I was shocked at how loud the unit is. I just hooked mine up yesterday and it is still humming/grinding away. The weight is not a problem since it was expected - there IS a battery in the unit, so it will be heavy. Regarding the shipping condition - with one terminal being unattached - I do agree - APC should determine a better way to allow easier hookup and reinsertion of the terminal. HOWEVER, the most important thing is that it works! Which it does - after several tests today (unplugging from wall, etc..). This is an adequate UPS - nothing really special. If you are ready to withstand a constant whirring, then go ahead and buy this UPS, because it does work.

The shipment box bears the APC corporate motto: "Legendary Reliability". Indeed, I've been using APC uninterruptible power supplies practically since the 1980s, and I've always found them to be completely reliable, as billed. When the power goes out, the computer stays on. When the power flickers, the UPS gives a warning beep or two, but the computer doesn't notice a thing.

Of course, batteries don't last forever and circuits may gradually degrade, so I've always made it a point to buy a new UPS whenever I get a new computer. So it was that, with my latest purchase from Dell, I included a pair of the recommended "APC Back-UPS ES 725 Broadband Backup Power Supply" units, one for each computer.

When the units finally arrived, I was in for a rude surprise on a couple of counts. The first was the utter unwieldiness of the things. They weigh 18 pounds apiece. For safety reasons, they ship with the batteries unconnected. So my first act as a user was to attempt to wrestle the connector in place without 1) dropping the UPS on my toes and 2) bending or breaking the little plastic doohickey which covers the power terminal. Finally I got the plug in place, only to find myself wrestling with the battery which refused to seat itself nicely so I could get the cover in place.

Next step: plug the units into the wall and let them charge for 16 hours. Now that's when the fun really began. Another reviewer described the sound as being like a field of crickets. I only wish. I could live with some soothing chirping. Mine, both units, sounded like a cross between a Norelco rotary razor with rusty blades and a swarm of angry hornets. It was very unpleasant. Was there something wrong with the transformers? Would they burst into flames while I was at work and burn the house down? Would I go crazy from the ringing and cut off my ear like Vincent Van Gogh?

After a day of charging the units, it was time to wrestle them in place and plug in the computers. When I hit the power switch for either one, the device got really quiet for a moment, then let out an ear-piercing shriek. Remember the scene where Sam, Frodo and Gollum hid in the Dead Marshes as the winged Nasgûl swooped overhead, searching for the Ring? It was that kind of shriek. My ears are still hurting just thinking about it.

No way. Back into the box they went. (It was, I might add, far easier to disconnect the batteries than to connect them.) I contacted Dell, and hopefully they'll take these turkeys back. Otherwise, I guess I'm stuck with really hefty, expensive paper weights.

Shame on APC for shipping such monstrosities. Maybe their QC people should take off their headphones and actually listen to the devices they're testing. This makes me very reluctant to buy anything else from APC, even though in truth all of the units at work seem just fine.

And remember: never, ever get between the Nasgûl and his prey.