Unsurprisingly, a UPS with modest power output requires modest ventilation. Only the left two-fifths of the slots you see are actually open, while the right ones are purely cosmetic to present a uniform pattern from front to rear.
Under the unit, we see three mounting holes with slots accommodating either horizontal orientation with the cord to the left or vertical orientation with the cord facing the ground. A serial number label occupies the area where the fourth mounting hole would have been, and the tool-free sliding battery compartment door accounts for about half of the bottom surface area.
Customary Label Shot
There's nothing unusual here: basic electrical specs, familiar warnings about not removing the cover due to no user-serviceable parts inside and shock hazard, a warning about possible explosion hazard from using the wrong replacement battery type and a notice about the output being non-sinusoidal with a THD of 45% and highest harmonic up to 35%.
I usually poke fun at APC for omitting stuff in translation, but the French instructions are verbatim.
Designed For Serious Shipping Abuse
Do you remember how I was unimpressed by the wimpy tongue connecting the middle of the battery door to the bottom of CyberPower’s LX1500? If you take my reinforcement suggestions and dial them to 11, you get something similar to what APC does here. Not only does the company split the tongue in two and make them thick, but it also includes multiple reinforcement ribs, despite the door being much narrower. That makes me wonder what sort of shipping abuse prompted APC to over-engineer the battery door so much.
Inside the Battery Compartment
With the battery out of the way, you can read a label on the interior wall telling you about the risk of electric shock, even with AC power disconnected. Ironically, it is nearly impossible to access this label without taking the battery out first. That label should have been on the battery door where it could be read without having to disconnect the positive cable.
Genuine Slap-On Label
The Genuine Replacement Battery Cartridge sticker lets you know that this battery meets APC’s performance requirements and the UPS' various safety certifications. From the battery dimensions, I expect it to be in the seven to eight amp-hours capacity range.
Under The Label
Hidden behind APC’s RBC label is a Kung Long WP7-12 battery with a 28Wh/cell rating. It looks like this Vietnamese manufacturer is especially worried about people incinerating its batteries: it is both the first and the last warning under the CAUTION header.
Also hidden under the label is APC’s permanent marker squiggle of approval, matching the color and line width as the other squiggle on the battery’s positive terminal plastic guard.
How does the Long battery inside the BE550G fare compared to the two best batteries I have come across so far in these tear-downs? It lags slightly behind the CSB part, and both fall considerably behind the SMART1000’s Yuasa battery that packs 8Ah in the same physical dimensions as the other two’s nominal 7-7.2Ah.
Four recessed screws hold the unit together. On the bottom of this picture, you see the back of the protection-only outlets with a common-mode filter choke located downstream. Introducing a few microhenries worth of inductance between the “protected” outlets and the MOVs will degrade surge suppression performance. That first choke should have been directly at the cord’s entry point instead, somewhere in the bottom-right corner.
With the transformer and PCB out of the way (thanks to having connectors for everything), we can see a second common-mode choke on the battery backup outlet feed wires and the breaker.