Review: 70mai Power Station Tera 1000 (1200W/1043.9Wh) (PN1020F)

Shopping around for more power stations, I was looking for something a little different to try. Thanks to a few generous Woolworths Everyday Market cashback offers, I decided to do a quick search and came across the 70mai Power Station Tera 1000 listing at about AU$579. This power station comes from the Xiaomi-ecosystem company most famous for their dashcams, offering 104.9Wh of storage and 1200W maximum continuous AC output. It seemed to be just what I was after and before I knew it, I had already bought it under the regularly-offered 30% (AU$150-cap) cashback offer. So let’s see if it’s any good and where the catch is …

Unboxing

The unit arrives inside a cardboard overpack, but mine seems to have been opened before delivery and then re-sealed. Perhaps this unit had been checked – maybe it’s one of the first to sell here in Australia as I’ve not seen much mention of this model on the local market. The sides of the box make it clear that the package contains Lithium-Ion Batteries.

The naming of the product itself is rather odd – “Power Station Tera 1000”. The order of the words doesn’t quite roll off the tongue. The model is PN1020F.

Opening the cardboard overpack, there is a protective sheet of cardboard. The retail print cardboard box is inside, complete with a very convenient handle, so you don’t have to do the classic “tip-over-the-box” gymnastics to get it out.

The design of the packaging is minimalist. Product shot on the front, the brand and the model name.

Even the sides focus only on the brand name, while the rear shows the product from different angles with a single specification label.

The full specifications are given above – it claims to have a 1043.9Wh capacity based on a 36.5V nominal voltage. This suggests to me that it’s probably a 10S configuration of regular Li-Ion cells rather than the more common LFP in this application. Li-Ion cells may have a higher energy density, but they do get a bit “explosive” in case of damage or defects and they pay with a lower cycle life. This explains why the unit is sold with a 1000 cycle life to 70% claim – where ordinary LFP often gets 4000 or 5000 cycles to 70%. In light of this, the unit being a bit cheaper than competing units is not surprising, but it would seem this unit isn’t all that new either – the production date of 01/2023 suggests this unit is already three years old.

Nevertheless, it has a host of different outputs – things to note include the DC5521 outputs being limited to 3A maximum, the AC inverter output claiming 1200W continuous and 2400W surge, the presence of fast (60W) and slow (18W) USB-C ports and fast (18W QC) and slow (5V 2.4A 12W) USB-A ports. Charging via solar is possible at up to 200W (12-27V at 10A maximum) and charging via AC is at 880W maximum. Also standard is Bluetooth 5.0 connectivity.

Opening the box, there is a small accessories pouch in the top foam end-piece. It’s nice to have such thoughtful additions, rather than just another disposable plastic bag.

The unit is underneath, wrapped in a plastic bag.

Aside from the two things just mentioned, there is also a short user manual leaflet.

The unit is a very rounded, integrated design that centres around a single, central, silicone-wrapped handle upon which the brand is depicted in relief.

The front of the unit is a mess of ports with operational regions carved out. The top region is the power button (orange), display, four interface buttons and lights (two dark squares). Below and to the left is the DC input region; to the right, the DC output region with its activation button. Finally, below that are the two AC outlets (Jake Time JT-A45 panel-mount sockets) with its own activation button.

A captive rubber cap protects the cigarette lighter socket output.

Charging input is in the rear, protected by a rubber flap. The product information label is also located on the rear.

The information label provides the same information as the outside label. The unit carries the Australian RCM making it legal for sale in Australia. There is a QR code for you to activate your warranty.

The AC input is via a JEC-branded IEC socket.

Two broad, long and thick rubber pads form the shock-absorbent feet for the unit, which combined with its weight, means it doesn’t move when placed down onto a surface.

Both ends of the unit are covered in a metallic grille with a large fan aperture for cooling.

Inside the accessories pouch is a mains charging cable and a cigarette lighter charging cable for use in a car.

The mains cable comes from Chuang Xu (CX-28 plug, CX-25 socket) and it carries both the Australian RCM and SAA numbers. The rating is claimed to be 7.5A/10A.

The wiring itself claims to have three 0.75mm^2 cores, which is definitely enough for this power station load and could carry 10A in theory albeit getting a bit warm – I usually prefer 1mm^2 for 10A but the standards apparently allow it.

The cigarette lighter charger cable is 16AWG and ends in a DC7909 style plug. This is a bit of an awkward one, but apparently, it is still common amongst some brands of power station. The solar input on the power station also uses the slightly less popular mini Anderson (PP30) style connection.

70mai App

The use of the app with the power station is not mandatory – it can be used just fine without it. Although having the app can unlock some conveniences, so I thought I’d give it a try.

The app you need to install is the 70mai App, the same one you would use if you had their dashcams.

You will need to agree to their terms and login with an account. If you’re a Xiaomi ecosystem user, I believe you can login with your Xiaomi/Mi account details as that’s what I did. There doesn’t seem to be a way around signing in for this app.

The app will request a number of permissions, but briefs you upfront as to why they are needed. Once they are granted, then you will be at the home screen on the devices page with no devices in the list.

You can then proceed to add a device, but it won’t find the Power Station Tera 1000 as it appears to need a manual addition process. By scrolling down the list and choosing the power station, you are given instructions on how to place it into pairing mode.

The unit can then be found and added …

… except if the app detects you have a VPN or proxy connection, then it stops you and forces you to turn it off before allowing you to add the unit. This seems unusually hostile and I can’t see a good reason for doing so – perhaps they’re overzealous on data collection and grabbing your IP address to ensure you’re in the region that you say that you are in.

The pairing needs to be confirmed on the unit, making this a “firm” pairing. It should be good news when it comes to security. Once complete, then you are ready to go.

The app will also ask you to manually set the region correctly.

With the station added, the home screen how looks a bit like this – you can either access the unit for remote control or see the usage statistics, which shows you the lifetime energy throughput. I suppose they will be relying on this to defend against any warranty claims – of note, the vendor that is selling the unit only gives one year of warranty. I’m not sure how the ACL will go on this one when the Power Station Tera 1000 website says the following:

Running 1000 cycles to 70% capacity, the Tera is extremely long-lasting and can support around 5 years of use.

If purchased via 70mai directly, apparently, they are covered by 18-month or 2-year warranty depending on the region of purchase. So the local resellers offering just 12 months is a bit of a shame.

The device control page shows the battery status and gives you the option to see what the inputs and outputs are doing and make changes to their status. Unlike some other power stations, toggling the master power switch only powers down the power station – it does not turn off the Bluetooth. Therefore, you can power up the power station remotely too! There is simply no way to disable the Bluetooth on the unit.

Here’s an example of what the input page looks like.

Some of the toggles are just plain toggles – e.g. ECO mode does not give any possibility to configure the ECO mode threshold. There are a few unique features – for example, scheduled turn-on of an output in 30 minute increments.

The power station settings page does give some ability to configure the station, but these are also accessible via the front panel of the unit.

The ability to change the output voltage is an uncommon one, but might be appreciated if you have some China-market products which are 220V native that aren’t too happy with the harmonised 230V, for example. Or you have an Australian native product that requires 240V but underperforms a bit at 230V. For most users, 230V is just fine.

The device management page provides the ability to rename the station, update the firmware and provides the MAC address of the station. There were no firmware updates at the time of publication. The fault list is very useful though – this power station has a lot of protections and thus often will throw a random code. The codes are listed below for convenient reference – another section of the electronic guide gives key troubleshooting steps, which is good.

All sounds good, right? It is, when it works. But more than a few times, it’s done this …

… attempt to connect and it causes the power station to reboot while the connection itself fails. This was a big bummer for me, because I was running some critical loads off the DC output and trying to check the status caused it to reboot. Drats. I guess I won’t be using the app all that much then …

User Experience

On the whole, the 70mai Power Station Tera 1000 clearly had its own “flavour” when it comes to priorities and it’s certainly got some advantages and disadvantages.

The first thing was the use of Li-Ion cells rather than LFP cells – Li-Ion cells are more energy dense, so that enables a smaller and lighter power station for the capacity. Tera 1000 weighed in at 12.7kg, the lightest of the 1kWh class stations I’ve tried, but not by a big margin. Part of the downside appears that the station might be using cylindrical cells where the weight of the shells would be a downside. The other is simply that the station has a good, strong and sturdy chassis that is designed to cope with some rough handling – that comes at a small weight penalty as well. The one silicone rubber handle is adequate, but it may get a bit heavy for one-armed carry if you’ve not been to the gym. This does give the station a bit of a unique place on the market – the only other Li-Ion power station of this size class that I know of is the ZLOS Ekobox and that’s one I don’t own.

Of course, the Li-Ion cells do have a few downsides. Charging speed seems to be more limited, especially if you want to avoid rapid capacity degradation. The cycle life is quoted as 1000 cycles to 70%, which is shy of the 4000-5000 cycles of LFP cells to the same level. In case of damage or manufacturing faults, cell failures for Li-Ion tend to be much more of an event … some may call it “vent with flame” (the technical term), while others would say that it “exploded”. So perhaps this is a risk you might not want to have, especially with the large number of cells that might be inside – at a guess, 36.5V means it’s a 10s configuration with about 27Ah in parallel, which might be 6 cells of 4500mAh for a total of 60 cells at a wild guess.

The next thing is the focus on user-friendly interfaces. This is the first power station that I’ve met with a colour graphic LCD rather than a segment LCD. While I’d argue that segment LCD may be easier to read in direct sunlight, the graphic LCD provides a lot more flexibility.

During charging, for example, we can see pictorial indication of the charging status and colour indications as to the battery status. The instantaneous wattage, including the “slow start” is easily visible along with estimated time, even though the font is a bit smaller than most other stations.

Similarly, the use of colour is used to depict status during discharge.

An idle status has the capacity centred on-screen while errors appear in the top right in amber. This makes it clear as to what is going on with the power station. The row of icons on the right align with the physical buttons on the panel, forming “soft” buttons (as you might have had on a Nokia phone or an ATM from the 90s).

The only time the display gets confusing is when both charging and DC discharging occurs, which results in this tabular format display instead. The capacity bar runs across the top, with outputs on the left column and input power on the right column. The power station has an internal menu which allows for practically all the features to be configured without the app. I think this is an excellent design choice.

Using the power station, I got the feeling the electronics inside are well-designed. The site boasted of plenty of use of Texas Instruments chips and it seems it was not short on protections, resulting in throwing up error codes as soon as any DC output was overloaded. The battery fuel gauge was a bit conservative initially but the accuracy appeared to improve over time. The unit appeared to be quite efficient in informal usage, as it was very quiet and the fan only escalated to a low roar under high-rate AC discharge. All other scenarios, it appeared to either be off or running very slowly – I suppose that’s why they term it the “back-up fan”.

Because the fan isn’t on a lot of the time, we can hear some of the internal components making noise – AC output does cause a small “ticking” noise that is load-level related. I suspect this is just from magnetostriction of the output filter inductor or due to discontinuous switching and having high instantaneous current changes on the DC side of the inverter. This can get slightly noticeable.

But perhaps the big downside of the design is the lack of pass-through capability for UPS applications. In fact, you can’t even run it like a double-conversion UPS as the AC output is automatically turned off as soon as AC input is detected. This is a big shame – even if it had no pass-through and operated double-conversion with losses, it would have been more useful to me in that way. Having the power cable enter in the rear for charging is a bit awkward to, as it means I can’t sit the back of the unit against a wall while charging. That being said, the limitations in front-panel area are well acknowledged.

I didn’t have quite the time to test it with my solar panels, so I can’t be sure if it wakes itself up every morning to charge but its 200W 10A-limited input does mean that, unless your panels are perfectly matched and your solar conditions are ideal, it’s unlikely a single day would be enough to charge the station completely. The choice of Anderson PP30 or DC7909 input is considered a bit less convenient – I think the majority of stations have moved towards XT60 as a better choice but at least adapters can easily be built or purchased. It’s a shame that none are included in the package.

The light is also an interesting design – it almost reminds me of LCD screen backlights or X-ray lightboxes. It’s diffuse but it is also integrated into the flat panel at the top. I found them not quite bright enough to be useful and a bit awkward in terms of their positioning. Like the case in other power stations, I usually find the integrated lights to be more of a gimmick than a practical feature.

Testing

This section contains the results of measurements made using various pieces of test equipment which include the Tektronix PA1000 Power Analyser, Thermal Master P3 Thermal Camera, FNIRSI FNB58 USB Tester and Rohde and Schwarz MXO4 Oscilloscope.

USB Output Modes

The higher-powered USB-C port supports 60W with fixed PDOs including 12V. The port also supports many legacy quick-charging protocols as well. This is enough for basic laptops but may not be ideal for some phones (as they may prefer PPS to reduce heating while charging by having a more optimal voltage).

The lower-powered USB-C port supports 22W with two PPS ranges. The port tops out at 12V, while also supporting many legacy quick-charging protocols. This is most suitable for phones or tablets.

The two USB-A ports vary in output as well – one of them supporting legacy quick charging protocols while the other one does not, acting as a basic DCP with Apple 2.4A support.

Discharge Tests

The first test was using the heaviest AC load I have – a fan heater that nominally draws 1.9kW. As the unit is only capable of 1200W sustained output, the initial power surges close to 1350W before being regulated in constant-voltage mode at a power near 1200W throughout. The unit managed to deliver 833.3Wh in 41m 53s with 79.9% estimated discharge efficiency.

Reducing the load to a more modest 150W halogen lamp (my go-to load for capacity measurement as it better represents the usually-modest demands placed on such units in practical long-term use applications), the unit was able to deliver 906.1Wh in 6h 23m 47s, which corresponds to an estimated efficiency of 86.8%. This is a near record result for this power level, besting the Anker Solix F1200 (71.6%), DJI Power 1000 (76.3%), Allpowers Volix P300 (79%), Ecoflow River 2 (84.8%) and Bluetti AC2A (86%), some of which are smaller units that usually mean their inverters have lower quiescent losses. The only ones to achieve better were the VTOMAN Jump 600X (88.9%) and the failed Yard Force U1000 (91.4%), although as these are estimates based on the claimed/printed battery capacity, they can be skewed by variations in cell capacity and the AC-to-AC cycle efficiency is a better measure overall of the whole system efficiency.

Looking at endurance with the lowest reasonable load, a 2.9W LED lamp lasted 72h 15m 37s with a 20% estimated discharge efficiency and about 11.6W of estimated self-consumption. For other power stations of this capacity class (1kWh), it easily beat the 41h from the DJI Power 1000 and the 67h from the Anker Solix F1200. A good result, albeit, I’d always hope for even better efficiency if possible. Note that the bumps in the curve are due to me covering and uncovering the lamp during test – the bright light would otherwise interfere with my sleep.

The output voltage from the power station is very stable otherwise – only making a slow movement initially and staying mostly flat thereafter.

When it comes to USB-C discharge, the power station delivered 901.5Wh in 15m 22m 45s, achieving an estimated 86.4% discharge efficiency at 9.3W of self-consumption. While higher DC-DC efficiencies can definitely be attained, this is a good result when compared with the DJI Power 1000 (81.5%) and the Anker Solix F1200 (73.3%).

The cigarette lighter output, loaded at 10A, delivered 924Wh in 7h 8m 50s for an estimated 88.5% discharge efficiency and 16.8W of self-consumption. This, again, was better than the DJI Power 1000’s accessory lead (83.1%) and the Anker Solix F1200 (82.4%). So it would seem the 70mai Power Station Tera 1000 has definitely prioritised the conversion efficiency despite having a sophisticated colour LCD screen and Bluetooth Low-Energy connectivity.

Unfortunately, due to a lack of time and the need to place the unit into service, I did not run a fridge load test to see how long it would last running a fridge. This was seen as less important, especially in the context of the solar sharer offer (SSO) as this unit does not support UPS, so charging the unit will cut off the AC output making it unsuitable for keeping an AC-powered fridge alive between free electricity periods.

Charging Tests

Regardless of charging speed, the charging efficiency is very similar at around 85.2%. The charging speed, however, is slower than that of the LiFePO4 (LFP) type stations which are often in the 1h to 1h 30m range. Instead, the 70mai Power Station Tera 1000 takes either 2h 12m 21s in fast mode or 4h 3m 31s in standard mode to fully charge. As a result, not only does the power station not win on cycle life endurance, it also suffers a charging speed penalty as well as not supporting pass-through UPS for AC loads – the only pass-through supported is for DC loads only. Instead of tapering down the charging power, it seems to do so in several steps. On the upside, this means that after charigng is complete, it sips a tiny 0.8W from the wall (a more fine-grained test of this is shown later in this posting).

This does let us work out cycle efficiency – 906.1Wh out / 1225.3Wh in = 73.9% AC-to-AC at 150W output. This is pretty decent – for comparison, the DJI Power 1000 (67.7%) and Anker Solix F1200 (65.2%) both achieved significantly less as stations of a similar size. Even my other stations of varying sizes rarely came close with the exception of the slow-charging VTOMAN Jump 600X – Allpowers Volix P300 (69%), Ecoflow River 2 (67.8%), Bluetti AC2A (67.3%) and VTOMAN Jump 600X (73.6%). Definitely a commendable result.

When it comes to solar input, the input is strictly capped at 10A, but seems to hover around the 9.75A region with some oscillation, possibly due to the actions of the MPPT or due to some granularity in the duty cycle adjustments of the internal converters. The available charging power thus depends, to some extent on your available voltage. At 12V input, it took 11h 22m 12s to charge the unit, consuming 1298Wh in the process for an 80.4% efficiency (estimated). This is hastened to 7h 8m 44s at 18V (a common maximum-power voltage for 12V nominal solar panels) with an estimated 86% charging efficiency. At the absolute maximum allowable 27V input, the charging took 6h 27m 31s and was also similarly efficient at 86.2%. Once charging is complete, no quiescent current is drawn from the input.

Plotted as a function of power, the 200W input is realised for 27V. But at 18V, it behaves more like 175W input. At 12V, this falls to about 117W. As a result, ensuring you have the right solar panels will help optimise the use of the input – ideally, to ensure you achieve the 200W ability, the Vmp of the panels should be above 20V, while the Voc should be below 27V. That does potentially narrow the set of best-compatible panels and might lead to some compromises being necessary.

Unfortunately, as the unit was placed into service before I had the time to test it with solar power input, I did not determine whether the unit wakes itself up every morning to collect energy on its own.

Standby Power

Using the PA1000 power analyser and PWRVIEW, the IEC 62301 standby power test gives us a result of 0.79946W +/- 0.0022307W. Or we can call it an even 0.8W. Unfortunately, because of the waveform characteristics of its draw, we were not able to “pass” the test due to the uncertainty being above the required limit – this just means the power analyser isn’t “good enough” to guarantee an accuracy meeting the requirements of the IEC standards, but it’s more than accurate enough for a layperson.

Thermal Images

The Thermal Master P3 agrees – this unit was pretty cool in operation. These images were taken when the unit was charging, showing heat in the top left side when viewed from the front. Surface temperatures reached a high of 33 degrees Celsius, inside the handle, where the electronics are located in the top-half of the unit.

A similar high reaching 35 degrees Celsius is seen when the unit is viewed from the side. It seems the higher efficiency of the unit’s converters pay dividends when it comes to the heat that needs to be managed.

During high-powered AC discharge, the top-right side of the unit heats up, reaching just shy of 40 degrees inside the handle.

Once again, a similar temperature is registered when looking through the ends of the unit, suggesting that it’s fairly comfortable inside, despite also remaining quiet with its large, low-noise and low-tone fan.

AC Output Waveform

A check of the output waveform on the Rohde & Schwarz MXO4 with high-voltage differential probe shows that the output is pure-sine-wave as promised. The waveform does have some residual ripple on it, especially when crossing the zero line. The fundamental is 45dB above any of the noise.

Loaded with 150W halogen lamp, the noise situation improves slightly with the fundamental now being 49dB above any harmonics.

At 900W load with a fan heater, it seems higher-frequency noise components near 1.5kHz are appearing. The fundamental is now 44dB above the harmonics.

When “overloaded” into constant power mode, we can see the voltage maintains a sinusoidal waveform and the voltage is reduced. However, the shape of the harmonic series changes and it appears the harmonics have not changed dramatically, with the fundamental being 43dB above the harmonics. In all, I would consider the waveform output quality quite decent – it’s unlikely any appliance would complain about it.

Conclusion

The 70mai Power Station Tera 1000 is a bit of a strange power station, as it is one of the few stations that I know of that still uses ordinary Li-Ion chemistry rather than the more common LiFePO4 (LFP) chemistry. As a result, it does gain a volume and weight advantage due to greater energy density, but at a cost to cycle life (1000 cycles to 70%), charging speed (2.25h in fast mode) and potentially safety. To some users, this may not matter – especially when the power station is being used for occasional trips rather than everyday, with the improved density being perhaps an advantage in reducing the load that needs to be carried.

As a power station, it feels well built with a sturdy chassis, premium-feeling materials, high-efficiency power conversion and Bluetooth remote-control via the 70mai app. By comparison with many of the stations I have tested to date, it has demonstrated the best cycle efficiency to date at 73.9% AC-to-AC at 150W draw. It’s quiet and is rarely audible, with its large fan having a pleasantly low note. The AC output is also capable of constant power operation for simple appliances that have a rating above the 1200W continuous rating.

However, there are a few major drawbacks aside from the cycle life and charging speed mentioned earlier. A key one is the lack of UPS functionality and AC pass-through. Whenever the unit is charging, the AC output shuts down automatically. This is not ideal if you intend to use it with AC equipment over long periods. The advertised pass-through functionality works only with DC. The LCD can be difficult to read outdoors and the integrated light is very limited in its power. The inverter’s 1200W rating is the smallest of the stations I own in this (1kWh) capacity class, which may limit compatibility with certain appliances. Finally, the 70mai app does not seem to be all that reliable – I suffered many connectivity issues that resulted in the reboot of the power station, cutting off all connected loads unexpectedly. The local warranty being just 12-months is also a potential risk.

In all, when considering the slightly-more affordable price compared to some LFP power stations, perhaps having some limitations and a limited cycle life is fair. However, it seems more of a unit that appeals to those with occasional use requirements rather than those looking to make it an “everyday-cycling” affair. For occasional uses, perhaps the smaller size and weight is of a benefit. Unfortunately, for me, I’d rather have a slightly bulkier, heavier and more expensive unit with 3-to-5 times the cycle life, UPS capability, faster charging and a longer warranty. The cost differential just isn’t enough to favour the Tera 1000. But there’s no denying – the electronics inside this unit are definitely a cut above the others on efficiency.

I hope you enjoyed this power station review. I hope to make this site a bit of a “home” for some more power station reviews in the future … but one person can only afford to buy so many! If you’re a company and you’re interested in contributing one for review, then take on my review challenge and reach out.