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CyberPower EC350G UPS Tear-Down


The unit’s bottom is covered with substantially more text than we're used to. Another detail that tends to dominate at least one side of a UPS but can easily be missed if you aren’t looking for it is the battery door. How many people will look for one before they actually need to replace the power source? I look before I open these devices so I can disconnect their batteries first. For the average person, this translates into the EC350G being mostly disposable, suggesting the whole unit should be recycled instead of recycling the battery and reusing the UPS.


CyberPower could not get English or French right in their redundant cautions, such as the brow-raising “Risk of electrical shock-hazardous inside this unit are energized from the battery” The French text has a bunch of lesser grammatical errors and missing words, but nothing quite as noteworthy.

There are multiple mentions of battery replacement related warnings even though there clearly aren’t any means of accessing the battery other than removing the four cover screws. Smells like a free license to pop the rear cover off and expose the electronic bits without voiding the warranty to me.


Here’s another caution referring to battery replacement in the top-right corner, along with a suspicious 6.0 Ah maximum battery size. Why do I say suspicious? Because a 6.0 Ah battery would weigh around 4 lbs on its own, and the whole UPS weighs only 4.54 lbs, which clearly means that we aren’t going to find a 6.0 Ah battery. Based on the electrical specifications area, CyberPower reuses the same outer bottom molds for its 350, 550, and 850 VA units. I bet different interior molds are used to accommodate each model’s different battery.


What do we find after popping the cover off? Either a huge PCB or an awfully tiny battery. The battery fits lengthwise between two screw wells and has about two centimeters of height clearance with the PCB to fit a ~25% taller power source. I don’t see how a 6 Ah battery would fit.

Different Weight Classes

There is no optical illusion or fancy shot composition at work here. In the background, weighing at 1.95 kg and 151×51×94 mm is the BGE90M’s CSB HR1224 battery. In front, weighing in at 0.93 kg and 102×48×66 mm is the EC350G’s battery, BBB’s CPS3.6-12, which appears to be an OEM part number with no corresponding specification sheet available. The next closest thing I could find from BBB is the SHR3.6-12. I will be using its specs as stand-ins for the CPS3.6-12.

Pay fifty percent more for a UPS with three times the VA rating; get half the battery.

Battery Comparison

On my normalized capacity table, it looks like BBB’s SHR-series battery, which I presume stands for Super High Rate discharge, manages to pull ahead of CSB’s HR1224 at the not-so-super discharge rate of 30 minutes. From a battery half the size and weight, though, this is still commendable.

If you are wondering why my HR1224 values are lower, it is because I originally guesstimated that it was a 6 Ah battery based on rough dimensions due to CSB omitting the 20-hour rating from its spec. I bumped it to 7 Ah based on weight, hence its reduced scores.

Getting A Little Stale

Based on the dating dial, the battery casing was molded in July 2014, meaning this is one more example of a battery that may have sat in warehouses for nearly two years before landing in a product for sale. Keep in mind that this is only a mold date. Final assembly and flooding (putting the acid in) may have occurred months later.

Board On Stilts

In the EC350G, the main board is mounted face-down to four spacers molded into the outlet strip's covers, with all of the wiring stuffed under it.

Under The Hood

What do we find under the board? A fair amount of messy wiring soldered directly to the PCB, which means this is going to be one of those tear-downs where wiring and everything attached to it will keep getting in the way, reminiscent of my Tripp-Lite SMART1000LCD tear-down experience.

Surprisingly, the control panel does have a connector on its cable. And unlike the SMART, it isn’t cemented down.


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C-C-Combo Breaker

Breaking the long streak of UPS and power bars combining 3x#16 gauge cords with 15 A breakers, CyberPower provides proof that 10 A breakers do exist in the EC350G. If you ever need to remove one of these breakers from its enclosure, you have to find some way to pinch the small barbed “wings.” The wide-open wings are there to hold some tension on the barbs so the breaker won’t rattle around.

Daniel Sauvageau is a Contributing Writer for Tom's Hardware US. He’s known for his feature tear-downs of components and peripherals.