Editor’s Note: Today we are launching a new review category for AnandTech: Uninterruptible Power Supplies. These devices are becoming more common as desktop users seek laptop-like reliability. All the while, this is also an area that we believe lacks good EE-informed systematic reviews. So our multi-talented power guru, E. Fylladitakis, applies his skills to inverters. As this is a new area for us, let us know what you think in the comments below!
While uninterruptible power supplies are nothing new in the PC space, proven battery backups for desktop computers have seen a resurgence in popularity in recent years. Improvements in power delivery technology, such as GaNs, have reduced costs and improved reliability, and meanwhile lithium-ion batteries, with their much higher energy density and larger volume weak, are also beginning to make inroads into the inverter market. All the while, with laptops outselling desktops in the consumer PC market, a PC that won’t shut down during a power outage is becoming the norm rather than the exception. So what better time to take a look at inverters?
To launch our inaugural UPS review, we start with a 1500VA unit from BlueWalker. BlueWalker is a company originating from Germany and specialized in the design and marketing of energy-related equipment. The company was founded in 2004, making it one of the oldest home inverter/AVR manufacturers still in existence today.
BlueWalker markets its retail products under the PowerWalker brand and has a very broad portfolio of hardware and software products available. For today’s review, we’re looking at the PowerWalker VI 1500 CSW, a 1500VA/900W UPS with true sine wave output.
| PowerWalker VI 1500 CSW | |||
| power capacity | 1500VA/900W | ||
| Output voltage | 230 VAC | ||
| Input voltage | 170-280 VAC | ||
| Type | Interactive line | ||
| True sine wave | Yes, rather) | ||
| Battery | Lead-acid, 2x 12V/9Ah | ||
| Backup time at full load | 3.5 mins | ||
| Half load backup time | 10 minutes | ||
| Sockets with battery backup | 2 (F-type) | ||
| Surge Protected Outlets | 2 (F-type) | ||
| USB-A outputs | 2 (2.1A) | ||
| Ethernet surge protection | Yes | ||
| LCD display | Yes | ||
| Dimensions | 99×280×410mm | ||
| Mass | 13.1kg | ||
Given that BlueWalker is a German company, it should come as no surprise that the PowerWalker VI is geared towards the European market. The inverter only produces at a nominal voltage of 230V, and likewise, is only designed to accept voltages around this range (sorry, Americans!). Beyond that, this specific version comes with 2 battery-powered F-type outlets, along with two more outlets with just surge protection. With a lead-acid battery capacity of 216Wh, it’s designed to run on a full charge for a few minutes, extending into the double digits to half a charge or less.
Pricing is particularly attractive with this inverter: true sine wave units have historically carried a significant price premium, but BlueWalker doesn’t charge nearly the same premium as true sine wave inverters from other major manufacturers, making the PowerWalker VI 1500 CSW a much cheaper inverter. – and almost €180, the one which is popular in the market accordingly. But can it live up to the same expectations of high power delivery without the same exorbitant price tag? Let’s find out.
The PowerWalker VI 1500 CSW inverter
We received the PowerWalker VI 1500 CSW in a relatively plain cardboard box, with the heavy unit well protected by thick pieces of packing foam. Inside the box we found a CD with compatible monitoring software, comprehensive manuals in multiple languages, and a USB cable.
The PowerWalker VI 1500 CSW is a tower type inverter with an LCD display on the front. Measuring just 410 mm deep, 100 mm wide and 280 mm high (16.2 in × 4 in × 11 in), it is very compact for a unit with such a high output. There are also two USB charging ports on the front, just below the LCD screen.
The LCD screen, when turned on, will display basic electrical numbers for the device, such as voltage, charge, and remaining battery life. It stays off most of the time and the user has to press the power button momentarily to turn it on.
At the back of the tower we find four power outlets. We’re testing the version with all four Schuko (Type F) sockets, but BlueWalker also offers this device with UK and FR sockets, plus a version with eight IEC sockets.
Note that only two outlets offer battery backup, the other two being for surge protection only. In fact, having only two outlets connected to the battery backup outlet of the unit is an atypically low number of powered outlets for a 1500VA UPS, as we typically see more of.
In addition to power protection, a non-destructive circuit breaker and an Ethernet surge protection path (input-output jacks) are also available with the PowerWalker. Finally, there’s a fan that only turns on when the unit is running on batteries, charging its batteries, or in automatic voltage regulation (AVR) mode. AVR mode basically runs the unit on mains power but forces the AVR circuitry to operate, which can be useful in some situations where mains power is on but very unreliable.
Over half of the front fascia is a door that must be removed to access the battery compartment. It is held in place by two small screws at the bottom of the device. When removed, you can see a very large connector that connects the batteries to the main unit. This must be unplugged to remove the batteries. If the batteries need to be replaced, the wiring must be disconnected and transferred to the new batteries. We found two Leoch 12V 9Ah batteries in the device, connected in series (24V 9Ah output). Leoch is one of the world’s largest battery manufacturers in China, and their products are considered to be of fairly good quality.
Opening the body of the unit we can see the large transformer and circuitry of the unit. The transformer is actually not very large for the 1500 VA unit and the amount of cooling it receives from the fan is quite small. This won’t be a problem for the stock unit, where the batteries will likely only last a few minutes, as there won’t be enough time for the transformer to overheat. Modifying the unit’s batteries to increase its runtime in any way without significantly improving its cooling capabilities would, however, be downright suicidal.
The electrical circuit left us with mixed feelings. Relays are supplied by Golden Relays, a reputable manufacturer, but capacitors are supplied by Aishi and Jamicon, suppliers considered poor. Eight IRF3205 MOSFETs generate the output when the unit switches to its batteries, MOSFETs that have proven to be reliable but, having been introduced over two decades ago, are now very cheap and perform relatively poorly compared to more modern MOSFETs. The finish is very good but the layout of the circuits is quite outdated.