The Anker 521 power station is a compact, portable lithium-ion battery pack designed to provide backup power on the go. This 256 Wh unit features a 200W pure sine wave inverter, a 60W USB-C port, 2 USB-A ports and a 12V car outlet. Weighing just under 7 pounds, it provides a solid amount of power in a small, lightweight package.
The Anker 521 joins a crowded market of portable power stations and offers a competitively priced option from major brand Anker. In this review, we’ll take an in-depth look at the capabilities, performance and value of the Anker 521 power station. Read on to see how this versatile unit stacks up.
Overview
The Anker 521 Power Station sports a compact size and lightweight design with a 256 watt hour lithium iron phosphate (LFP) battery. Despite the small form factor, it packs impressive capacity in a sturdy and portable casing.
With dimensions of 7.28 x 5.11 x 6.29 inches and weighing just under 5 pounds, the Anker 521 can be easily carried or tucked away. The exterior features a clean, modern look with rubberized feet and a large color LCD screen. The screen clearly displays key information like battery percentage, power levels, and estimated time remaining.
Thanks to the high-quality LFP battery, you get 3,000+ cycles while retaining at least 80% capacity. So you can rely on the Anker 521 to deliver power for over a decade. Overall, it provides portable power in a compact and convenient package.
Battery
The Anker 521 features a 256 watt hour lithium iron phosphate or LFP battery rated at 3,000 cycles to 80% capacity. In other words, this battery is designed to last over 10 years of frequent use and recharging. Lithium iron phosphate batteries have several advantages over lithium-ion such as improved thermal and chemical stability, making them safer and longer lasting. With a lifespan of up to 3,000 cycles, the Anker 521’s battery stands out compared to the typical 500 cycles offered by lithium-ion power stations. The ability to recharge over 3,000 times to 80% capacity means you can rely on this battery for over a decade before noticing significant degradation.
Charging
The Anker 521 can be charged in several different ways for maximum flexibility. It comes with a 65W AC wall charger that can fully recharge the 521 in around 4 hours. There is also a 12V car charger included that recharges at the same 62W rate in around the same time.
For solar charging, the 521 has an MPPT controller that allows up to 65W of solar input. With a 60W solar panel, you can expect another 4 hours for a full recharge. The USB-C port supports 60W Power Delivery, so it can recharge the 521 in around 4.3 hours.
A great feature of the 521 is its ability to charge simultaneously from multiple sources. For example, you can combine AC wall, solar, and USB-C PD to cut the recharge time down to around 2.5 hours. This makes it easy to top up the 521 even when you’re using it. The solar input and USB-C PD can both operate at the same time as the AC or car charging.
Output Ports
The Anker 521 has several output options to power or charge your devices:
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AC output: The inverter on the Anker 521 is a 200 watt pure sine wave inverter with two AC outlets. In my testing, it was able to output around 215 watts continuously. This is plenty for most small appliances like laptop chargers, CPAP machines, monitors etc. The pure sine wave ensures no interference with sensitive devices.
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DC output: There is one 12V car lighter style socket capable of supplying up to 10 amps or 120 watts. The output is regulated to 13.3V which is great for powering 12V appliances like portable fridges.
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USB outputs: For USB charging, there’s a 60W USB-C PD port capable of fast charging laptops and phones. There are also two standard 5V 2.4A USB-A ports. The USB-C port supports bi-directional charging so you can also use it to charge the power station itself.
The variety of output options makes the Anker 521 versatile for powering a range of devices during blackouts or off-grid. The 12V DC output and USB ports ensure you can keep phones, laptops and key devices charged when grid power is out.
Additional Features
The Anker 521 has a couple handy additional features worth mentioning.
First is the power saver mode. This is enabled by flipping a physical switch on the unit which turns blue when activated. Power saver mode will automatically power down the Anker after a period of low power draw to conserve battery. While useful in some cases, it’s recommended to keep this off if using appliances that need continuous power like a CPAP machine or fridge.
The Anker also supports pass-through charging. This means you can charge devices from the AC, DC or USB outputs while simultaneously charging the Anker itself. Testing confirmed simultaneous charging from AC and DC inputs worked to deliver faster charge times. Pass-through charging provides flexibility to keep your devices powered in an emergency without draining the battery.
Testing
I took the Anker 521 into my secret laboratory where I performed a variety of tests on it.
Battery Capacity
I performed a double-fisted battery capacity test to determine the effective capacity. The DC capacity test scored 195 watt hours out of 256, or 76% effective capacity. This isn’t the best result, likely due to the DC regulation circuitry which consumes some power to keep the voltage steady. The AC capacity test scored slightly better at 200 watt hours or 78% effective capacity. While not record breaking, these results are decent for a power station of this size.
Output
I tested the 12 volt cigarette lighter output, which Anker claims can handle 10 amps. It had no problem supplying 11 amps at 11.8 volts with 128 watts of power. This can easily run a portable 12V fridge or other appliance. The pure sine wave inverter maxed out at around 215 watts before shutting off, just above its rated 200 watt capacity. It passed the 5 minute sustained cooling test without issue. There was noticeable inverter noise under heavy load.
Additional Tests
The Anker passed tests for simultaneous charging, USB charging while AC or DC in use, and demonstrated no interference on an audio amplifier when charging.
Noise
The Anker 521 is very quiet when charging thanks to its fanless design. However, when pushed to its 200W limit during sustained use, the inverter’s internal fan does kick on after a few minutes to prevent overheating. The fan is audible but not overly loud, measuring around 58dB according to my testing.
After a sustained heavy load, the fan will cycle on and off as needed. When on low speed, it’s much quieter and less intrusive. This is expected behavior for such a compact 200W inverter.
Unfortunately, some electrical interference is detectable when using sensitive audio equipment plugged into the AC outlets. The high frequency nature of the inverter causes interference across parts of the audible spectrum. It’s not severe, but you won’t want to power speakers or musical instruments directly from the Anker 521. Using it as a backup to charge devices is fine.
Pros
The Anker 521 has a number of benefits that make it stand out:
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Long battery life – The 256Wh LFP battery is rated for 3,000 cycles to 80%, meaning it should last around 10 years. This far exceeds the life span of most competing models.
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Dual charging capability – The Anker can charge from two sources simultaneously, combining AC, DC, solar, or USB-C PD to charge up to 120W total. This allows for very rapid recharging from multiple inputs.
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Power delivery USB-C – The 60W USB-C PD port allows fast charging of newer laptops, tablets, and phones. It can also function as an input for up to 60W USB-C charging.
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Pass-through charging – The Anker allows simultaneous charging and discharging so you can recharge it while still powering devices during an outage.
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Pure sine wave inverter – The 200W inverter outputs a clean sine wave that is safe for sensitive electronics.
Cons
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The Anker 521 lacks higher wattage quick charge USB ports, only including lower power 5V USB-A ports. This may limit fast charging for devices that support quick charging standards.
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While the power station can charge from solar at 65W, some users may prefer a higher solar input limit. The MPPT solar controller is hard capped at 65W max, so higher wattage solar panels over 100W won’t provide any benefit. Those looking to maximize solar input may be disappointed by the 65W ceiling.
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Because it uses a small, high frequency inverter in a compact body, the Anker does produce some line interference when using sensitive audio equipment plugged into the AC outlet. This may frustrate some users, though the interference was not severe.
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The inverter maxes out at 200W continuous, which is enough for smaller appliances but won’t power larger devices. Those looking to run appliances like microwaves or power tools may need a unit with a larger inverter.
Price
At $199, the Anker 521 is an incredible value for a portable power station of this capacity from a major brand like Anker. While the regular price is $259, during Cyber Monday it was marked down to only $199, which puts it in a class of its own and is a price you’d normally see from lesser-known brands.
For those looking at this later, be aware the $199 promotional pricing was for a limited time around the 2019 Cyber Monday. The regular MSRP is $259. Either way, Anker is known for delivering premium products at reasonable prices, and the 521 continues that tradition. With 256Wh of capacity, 200W AC output, and 65W solar input, you get excellent power specs and versatility at a very wallet-friendly price point compared to similar offerings on the market.
Solar Pairing
While the Anker 521 has built-in solar charging capabilities, for optimal solar charging you’ll want to pair it with an external solar panel or array. Since the 521’s maximum solar input is 65W, Anker recommends using a 60-100W solar panel for charging. You can potentially use a solar panel up to 120W, which may provide a small boost in cloudy weather when the panel output is reduced. However, the 521’s MPPT charge controller will limit the input to 65W maximum.
Ideally, you’ll want a portable foldable solar panel that’s easy to set up and position to maximize sun exposure. A panel with kickstands that allow angling it at an optimum tilt angle usually around 30-45 degrees depending on location and time of year. Ensure your solar panel has the appropriate connector to plug into the 521’s charging port, which is often an 8mm DC connector.
Some top solar panels to consider pairing with the Anker 521 PowerHouse include:
- Renogy 100W Foldable Solar Panel
- HQST 100W Foldable Solar Panel
- ACOPOWER 100W Foldable Solar Panel
- Jackery SolarSaga 100W Solar Panel
Aim for solar panels with monocrystalline cells for the highest efficiency. And look for panels with an IP65 weatherproof rating. With a compatible 100W solar panel, you can charge the 521 from 0 to full in about 4 hours of good sunlight. This makes solar charging a very effective option for the 521 PowerHouse.
Conclusion
The Anker 521 Power Station is an excellent entry into the solar generator market by Anker, a well-known and respected brand. Despite its compact size, it packs a good amount of power thanks to its high-quality LFP battery.
The dual charging capability provides fast recharging times, and the pass-through charging is handy for emergency backup power. While the output ports are somewhat limited compared to larger models, they will cover basic needs during outages. The unit performed well in hands-on testing.
For the price of just $199, the Anker 521 Power Station is an affordable option for home backup power and off-grid adventures. It’s powerful enough to run small appliances and charge devices, while still being portable at just 6.4 lbs. The 2-year warranty provides peace of mind on Anker’s build quality.
Overall, the Anker 521 Power Station gets top marks for its performance, thoughtful feature set, reputable brand name, and bargain pricing. It’s an excellent choice for a compact, entry-level solar generator.