A long time ago, I had purchased a Rockpals 500 and had since given it away in favor of larger batteries (1000Wh and recently, 1500Wh). Rockpals has made pretty decent power stations in the past, and I was intrigued to see how the updated version was. I actually wanted a 300Wh one to keep inside my car to power the car freezer whenever the ignition was turned off. Why would I have a freezer/fridge in the car? Grocery shopping. To keep things cool or frozen so I wouldn't have to rush home so quickly. Regardless, your situation probably is different, especially if you live in areas hit by disasters (hurricanes, tornadoes, fires, or just plain power outages). I cannot stress how important it is to be prepared for emergencies.There has been an increase in people taking emergency preparation more seriously.For this review, I borrowed my youngest brother's Rockpals 300W (2017 model) to compare with what has changed with this year's version. Right off the bat, you can see a significant, visual difference between the two. The older version was boxy and the new one has curves all over the place. The 2020 model also took away one of the more useful features of its older sibling: the two, built-in flashlights.CELL MANUFACTURERSToday's devices use Lithium-ion (Li-ion) and Lithium Iron Phosphate (LiFePO4) cells so they can pack more power in a smaller package and weigh less. However, Li-ion (which the Jackery is made with) also is more volatile whose risk increases as more cells are packed together. The quality of the battery cells and the BMS (Battery Management System) are crucial for safety.- Battery storage capacity is measured in Wh, and power output is in W (Watts)- The higher the Watt-hour (Wh) capacity rating, the more dangerous the battery could become if not handled rightBattery cells made by LG and Sony are among the best in the hobbyist world as are Sanyo/Panasonic, Samsung, and BAK Battery. I was not able to determine who made the batteries for this Rockpals as I did not want to open it up, and the company's tech support in the past did not answer my questions about their prior models.During my years of research, I found that use of lower-quality batteries could pose a serious risk to life and property and should become a crucial part in deciding what to buy. With that said, Rockpals is one of the more popular power station manufacturers on Amazon.IN A NUTSHELLRockpals 300 (PS300) is a light power station with a modern-looking exterior and a flashy, red color scheme. The 300W of energy (and peak of 500W) provides enough power for a small amount of electronics and small appliances, such as a laptop, television, mini fridge, medical device (like CPAP), and car freezers, but will NOT work for most rice cookers, and definitely not for a vacuum, water boiler, or circular saw.The hard, plastic material used to help shed weight (and cost) could be prone to cracking from hard falls or bumps, potentially exposing the Lithium-Ion batteries to puncturing. The fixed carry handle unfortunately cannot be folded, making it not ideal for packing things on top.Functionally, this is a good, portable power station with a multitude of AC and DC outputs. Rockpals upgraded its sibling with a USB-C PD with an acceptable, 30W output. This makes it useful for slow-charging supported laptops. The 12V and AC ports are both covered, keeping them clean from dust and spills.One thing I do not like about this power station, however, is that the AC output is disabled while its battery is charging. Only the DC-based outputs work (USB, 12V) while charging via wall outlet, car cigarette port, or solar. A cigarette port cable is included.PROS- At 280 Wh capacity, it is the same as the 2017 model-- Capacity to power a 30" LCD monitor and Mini PC for 3-5 hours, a Toshiba 50" Fire TV for almost 2.5 hours- AC Inverter capable of continuous 300W power (and 500W peak) - More details later- Very inexpensive at $250- Can power AC and DC (USB/12V Car adapter) at the same time (as long as they draw less than 300W combined)-- Laptop, tablet, phones, lights, fans, CPAP medical device, projector, TV, mini refrigerator, speaker, camera, DSLR battery charger, and SOME rice cookers- USB-C PD port outputs 30W- DC ports (USB, 12V) can be used while charging. AC port cannot.- Faster charging with MPPT controller (Maximum Power Point Tracking)- Informative LCD with LED backlight-- Total power coming in (via solar panel or AC adapter)-- Capacity left (as a percentage)-- Total power (AC and DC combined) being used--- Suaoki G500 displays the Wattage separately for DC and AC, which I prefer-- Unfortunately, estimated hours to full charge or empty is NOT shown- Pure Sine Wave (I did not verify the manufacturer's claim for this review) to help power sensitive electronics- BMS provides built-in overload, overcharge (automatically stops charging when the device is full), and short-circuit protection-- Fan to keep the station's temperature safe- Master power button must be long-pressed to turn on. This can prevent accidentally turning power on/off through a single press (ie. while packing away your camping gear)-- Can prevent accidentally turning on/off the output during transport, keeping the battery from getting drained-- I had previously criticized Rockpals, Jackery, and Goal Zero for not preventing accidental button pushes, and am happy to see that Rockpals had listened to that suggestion-- No automatic power off once no power is drawn/station has become idle- Multiple ways of getting charged-- AC power brick not very large and compact to stow away (outputs 45W)-- Solar panel (up to 100W)-- USB-C PD up to 30W- Decently compact at 10.5" x 5.3" x 8.5", though the higher-capacity, slightly larger Goal Zero Yeti 500x is still my favorite for its size and capacity- Portable at just 7.7 lbs- Bottom is well-protected by raised feet- Cigarette socket cable included- 1.5 year warranty- Readable manual, though details were scarce-- Goal Zero's manual, on the other hand, is VERY detailed and helpfulCONS- AC port cannot be used while charging. Only the DC ports (USB, 12V) can- Carry pouch is not included to hold AC charger and cables- From past experience, customer service can sometimes be difficult to work with- Batteries are likely not made by a globally well-known, Tier 1 manufacturer- No Anderson input port for solar charging-- You charge with an (optional) Anderson-to-8mm converter cable instead- Fixed carry handle cannot be stowed away-- Makes it difficult to stow things on top at the back of a trunk- Hard, plastic material makes the power station lighter, but could be prone to cracking from hard falls or bumps-- Given that Lithium-Ion batteries become more volatile as capacity increases, one should handle the product with care- Although the exterior looks modern, once I saw the Goal Zero Yeti 500x, I fell in love with the Yeti's design- No built-in flashlight or SOS signaling that the E1000 includes- Display is not as informative as I'd like-- Only shows battery charge level, input and output wattage, but no estimate of time remaining to full charge or to empty- Fan turns on during high peak and can be too noisy for some- Battery cannot be replaced. This can lead to unnecessary landfill waste- Cannot be daisy-chained to other Rockpals to extend battery capacity, though you may be able to do so through plugging one of them into the 12V cigarette port-- Some Goal Zero stations can be hooked up to other ones so power can be provided for an even longer time without needing to switch- Not waterproof. Keep it away from water splashes, rain, and pool!-- Lithium and fire or water can cause serious damage or injury!- No carry bag for the power station itself is includedINPUT PORTS- 1x DC In-- Accepts up to 120W-- Max 12-24V and 10A with no minimum wattage--- WARNING: Do NOT use a power source/solar panel that exceeds 24V or 10A!---- Be mindful that solar panels that are daisy chained in sequence/series may output more than 24V combined!-- Can be used for solar charging--- MPPT charge controller is built in--- I recommend using a panel that's between 30W – 100W at 18V (with the right Amps to equal 100W)---- If you attach a 200W solar panel (with 20V x 10A = 200W), it will charge at only 120W--- I did not test solar charging as the winter sun would not produce much energy- USB-C PD output port can also be used as input at up to 30WOUTPUT PORTS- 1x AC with 3 prongs (120V)-- Inverter can handle a continuous 300W, peaking at 500W. More on that later-- Pure Sine Wave Inverter (Did not verify that it truly is Pure Sine and not Modified or Square)--- Ensures clean power to protect against damage to sensitive electronics--- Generates less heat--- Note: Some manufacturers claim to be Pure-Sine when they are actually Modified or Square Waves- 1x Cigarette socket (12V, max 10A)- 1x USB-C PD (20V, 1.5A, max 30W)-- PD (Power Delivery) allows a device to be charged with up to 60W through the USB-C interface- 2x USB-A (5V, max 3.1A, max 15.5W)- 1x USB-A QuickCharge 3.0 for rapid charging of compatible devices- 2x DC Out (12V, 5A, max 60W)USAGE- To turn ON or OFF the entire unit, long-press the master Power button- To turn ON or OFF the Car/USB (DC) or AC outputs, press the corresponding button- To reset an Error condition that's shown on the LCD (ie. AC port is Overloaded), turn OFF the respective AC or DC output, and back on- Li-ion batteries have 500 charge cycles before capacity drops to about 80% from when they were new-- Product could, in theory, be charged up to 2,000 cycles — about 1/4 of total capacity is lost every 500 cycle- Unlike LiFePO4 batteries, Li-ion can operate only in temperatures between 32-104F (0-40C)-- Rockpals Battery Management System (BMS) prevents:--- Recharging in temps outside of 32 - 95F (0 - 35C)--- Outputting power in temps outside of 14 - 104F (-10 - 40C)- Battery, like all Li-ion, slowly drains over time even when station is powered off-- Could take 1-1.5 years to go from full to emptyCONTINUOUS VS PEAK OUTPUTThe AC Inverter provides a continuous output of 300W with a peak/surge of 500W- AC Inverter: Component responsible for converting battery (DC) power into AC for use by electronics- Continuous Output: As long as a device (or combination of multiple ones) does not exceed 300W, it can be used-- Example: A TV that uses 100W can be used because it is less than 300W. You can add more devices as long as they do not exceed 300W combined-- Example: A miter saw I have uses 1,800W, and because it exceeds 300W, it cannot be used- Peak/Surge: Almost every device temporarily draws more power when it is turned on. The highest amount it pulls during that time is the Peak/Surge. This power station can accept up to 500W-- Example: A TV that uses 200W (continuous) may temporarily suck up 400W (peak) when powered on. Because 400W is less than 500W (peak), this battery will allow the TV to turn on at that level for a few seconds (any longer, and it might cut power as a safety precaution). After a few seconds, the TV then only uses 200W (less than the continuous 300W limit) until the battery is drained-- Example: An unusual device that uses 250W (continuous) and surges to 1,500W when powered on would instantly be shut off by the battery. Why? Even though the device uses just 250W while already on, it jumps to 1,500W when powered on, exceeding the 500W surge limit of the power stationCALCULATIONSThe below calculations are rough estimates as conditions, quality, and product age can vary.CHARGING TIMES- Wall charger: 6-7 hours-- AC adapter was observed to provide 45W when charging level was at 67%-- AC adapter will gradually charge slower as battery reaches full capacity (for safety reasons)- 100W solar panel: depending on weather conditions, it should take about 5-6 hours. I did not test this as the winter sun is not very strong-- WARNING: do NOT connect panels sequentially or you may output too much voltage and fry the power station! Connect them in PARALLEL with a Y-Branch cable- Goal Zero Yeti 500x can combine its 8mm and USB-C PD ports for a total input of 180WHOW MANY WATTS DOES A DEVICE US?- Calc: Watts used by device = Voltage x Amperage- If a vacuum is 120V and 9.5A, it uses 1,140WIf a device draws more than 300W for an extended period of time, the power station will shut off as a safety precaution. This can also shorten the battery's lifetimeHOW LONG CAN A DEVICE BE USED FOR?- Calc: Hours available for device = Battery capacity (Wh) x 0.85 / Watts used by device-- Generally, about 10-15% of power is lost during power conversion- If a device uses 60W, it could last up to 3.97 hours (280 Wh x 0.85 / 60W)- Amazon TV I have uses about 100W-- If battery is full at 280 Wh, TV could run about 2.5 hours (280 x 0.9 / 100)HOW LONG DOES IT TAKE TO CHARGE A DEVICE?- Calc: Hours to charge device = Device's battery capacity (Wh) / Input Wattage- If a laptop accepts 60W of input and its battery capacity is 200 Wh, it could take 3.3 hrs to charge (200 Wh / 60W)HOW LONG DOES IT TAKE TO CHARGE THE ROCKPALS 300 WITH SOLAR?- Calc: Hours to charge battery = Battery capacity (Wh) / (Panel Wattage x [0.5 or 0.75])-- In a perfect lab environment, solar panels charge at the indicated wattage (ie. 150W)-- Expect to only receive 50-75% on a good, sunny day (ie. 75W - 113W), depending on environmental conditions, panel's age, and component quality-- Tip: Even if it is overcast, the panels will STILL collect solar energy. Keep charging!- If a solar panel is rated for 100W, it could take as fast as 3.73 hours [280 Wh / (100W x 0.75)] to chargeHOW DOES ITS CAPACITY COMPARE TO POWER BANKS?- Calc: Powerbank-equivalent capacity (mAh) = Battery capacity (Wh) / Voltage x 1000-- 1 Ah = 1000 mAh- A battery capacity of 280Wh at 3.6V is roughly a 77,778 mAh powerbank (280 Wh / 3.6V x 1000) or a 25,926 mAh at 10.8VTIPS- Always test your devices with the power station before you depend on it on the go- Lithium-ion batteries are volatile-- To minimize fire damage to your belongings or loved ones, store the power station in the garage and not inside the house. Best storage is a dry, cool place, however-- You cannot bring a battery of this capacity on a plane- With the right BMS, quality batteries, and other factors, the power station can be stored in the car while camping during a hot, California summer-- Keep the battery out of direct sunlight. I usually store it on the floor of the car and crack open the windows a tiny bit-- Do not USE in the car if temperatures fall below or exceed the battery's rated, operating temperature (32-104F or 0-40C)Keep your car cigarette lighter with the power station -- you could plug it into its 12V DC socket for starting a camp fire- If using a car charger, make SURE you only charge this station while the car is RUNNING. Otherwise, you'll deplete your car's battery and leave you stranded- If charging with a solar panel, be sure to keep the station out of direct sunlight as it could overheat-- A solar panel is NOT required to use the battery-- Rockpals 300 uses the MPPT solar charge controller--- Smarter, more efficient/expensive than PWM--- Suitable for larger systems- Can be used and charged at the same time. Manufacturers’ recommendations for their own products:-- Yes, that’s fine: Goal Zero, Jackery, Rockpals, nrgGo-- No/Not advisable: Suaoki- NEVER charge the power station itself in below freezing temperatures, or you will damage the Li-ion battery AND potentially limit its overall capacity-- You CAN use it to power OTHER devices because the generated heat will warm its battery enough to be within operating temps-- At below freezing temps, keep it in an insulated cooler and connected to a power source (ie. solar panels). The heat generated by the battery will keep it running as best as it can- Turn off any output ports (AC/DC) that are not being used in order to conserve power- Do not use any power station in a tightly enclosed area as it can overheat- To prolong the battery lifetime while in storage, keep the battery fully charged every 3-6 months-- Or, keep it plugged in when not in use and discharge it to 50% every 3-4 months-- NOT using the battery for a very long time can actually hurt its lifetime-- There is no "memory effect" in this station's battery. It is better to NOT let it completely drainFINAL THOUGHTSThe Rockpals 300 is a decent, new release for the company in that it has made some modern improvements (like USB-C PD) over its older, 2017 model. The 300W of energy (and peak of 500W) provides enough power for a small amount of electronics and small appliances, and is the perfect size for a quick trip or to charge something for a few hours (like my car freezer).The hard, plastic material commonly used by power stations to help shed weight and cost could be prone to cracking from hard falls or bumps, and as such, this product should be handled with care - a puncture of the Lithium-Ion batteries could cause severe harm. The fixed carry handle unfortunately cannot be folded, making it more difficult to pack things on top.