Pros: Works as advertised. I wanted to educate the first post on how long batteries in UPS units last. As per the instructions, the batteries should be replaced after 2-3 years. (Read the manual!) More usage, means less battery life. Lucky for us, these use easy to find sealed lead acid batteries. 2 in the main unit, and 4 in the expansion unit. These batteries can be purchased at a local Batteries+ for $35 or so each. Add 20 minutes of labor, and you are good to go for another 2-3 years.

Cons: None.

Overall Review: You can go with the APC battery replacement packs option at about $99 per pair, or you can do it yourself for $70 or so, and a little time.

Pros: With a litlle effort the batteries can be replaced by owner. APC does not make it easy. You can break one of the plastic fasteners. This is not critical, Batteries are the CP1290 model. Four batteries are needed since this is a 24 volt system like the UPS. The UPS series with a battery inlet is XS. Not all 1500VA units have the needed inlet. Remember the charging comes from the UPS so allow time for a full charge. Don't panic if the fan seems to run for awhile during the initial charge period. Seven AH batteries will fit but they lower the run time.

Cons: Case needs to forced open. APC could have designed this unit so that the batteries could be replaced by the owner. They could include a wiring diagram on the inside wall of the unit. I took pictures of the existing wiring before doing my battery replacing. Remember you are working with a 24volt system. I think if someone had the need to move the battery unit away from the UPS unit they could make wire splices using heavy gauge automotive wire and fasteners. My UPS doesn't have an LCD screen so I have both units hidden on the floor.

Pros: Needed to clarify on Spinedust's review - I have an APC XS 1500 and am staring at the port this external pack would plug into. Not sure what he was looking at, but this unit works fine for the XS 1500 UPS.

Cons: None

Overall Review: THE BR24BP looks more appropriate for the older XS 1500 unit (beige) - but the newer BR24BPG is functionally identical and compatible.

Pros: I ordered this at the same time as the BR1500G that it attaches to. So glad I did. Took my idle runtime from 15 minutes to over an hour and 20 minutes! Took my game time from 8 minutes to over 40 minutes, and my full computer load time from 5 minutes to over 30 minutes. Very impressive. We have some frequent power outages where I am (sometimes as many as one a day), so having a unit that can run for as long as it can is amazing.

Cons: I wish the cord that attaches this unit to the main unit was longer. It would give the user more options on placement, especially on a crowded desk. Why does this unit need to be within 10 inches of the main unit? I like the main unit on my desk so I can easily view the LCD, but I would like this extra battery unit on the floor behind the desk, where it does not take up space. Might need to find an extension for the cord somewhere...

Overall Review: Overall, its well worth it for me. If you don't have many power issues, or have a lighter load, you may not need to buy this extra battery pack. The main unit should give you plenty of time to shut down your computer. I just got it because, like I said, we have frequent outages lasting from 5 seconds all the way up to an hour, where the hour long ones are very rare. With this unit, I can keep working for upto an hour and a half without any electrical power. I also have my modem and router on this battery, so my internet does not go down when the power goes out.

Pros: At least triples your UPS battery run time.

Cons: APC will not exchange this unit. They do not offer a battery refresh kit for it and will not take it back at the end of it's life cycle. APC software only allows runtimes of up to 8 minutes with or without the BR24BPG. This means that even if your machine could run for an hour or more on batteries, the APC software doesn't allow for more then 8 minutes before it starts to shut it down.

Overall Review: The BR1500G comes with two batteries. This unit comes with 4 more of the same battery. The first con is something the user can get around if they have a local shop that deals with batteries. The batteries are an industry standardized size. While it says that there are no user serviceable parts inside, the batteries can be replaced. This is only recommended for people that have and know how to use a DVM and know what series and parallel mean in circuits. The battery shop might be will to help. The BR1500G said it could hold the load of my computer setup for 10-12 minutes at idle and 5 minutes at full load. This BR24BPG extended these times to 52 minutes and 25 minutes respectively. The software is rather irritating. I have power issues regularly and would've liked the option to keep the system up and running for 15-20 minutes. I'll probably end up killing the software after a few minutes of a power event.

Pros: It worked for about 2 years

Cons: After about 2 years the thing would just shut down and turn off the power to everything connected to it. So to the extent you buy this to prevent problems caused by the power suddenly going out on your computer - well this actually causes that problem. I bought 2 and they both started acting like this at the same time.