Alpha ESS Battery Review: Everything You Need To Know About The Storion-SMILE

Alpha ESS Battery Review

The Alpha ESS Storion SMILE battery is the second battery eligible for the SA Battery ‘rebate’. But is it worth considering?

Alpha ESS is a Chinese manufacturer of home battery systems.  Because they have promised to do some assembly in Adelaide they are now the second company eligible to receive South Australia’s substantial home battery subsidy, as reported by Michael here. More batteries will become eligible in January.

According to the South Australian Government’s Home Battery Scheme site, there are two models of Alpha ESS battery system eligible at this time — the Storion-SMILE-B5-GW and the Storion-SMILE5.  But Alpha ESS has told me these two models are almost identical.1  They have the following features:

  • From 5.5 up to 33 kilowatt-hours of usable storage when new.  Currently available systems have 5.5, 11, and 16.5 kilowatt-hours of usable storage.
  • Power output of 2.8 kilowatts for a system with 5.5 kilowatt-hours of usable storage and 4.6 kilowatts for all larger ones.
  • A built in 4.6 kilowatt hybrid inverter.  This makes it an all-in-one system and rooftop solar panels can be connected directly to it.
  • It can also be AC coupled and operate alongside any existing home solar system and solar inverter.
  • When solar panels are directly attached to its hybrid inverter it can charge its batteries with them during a blackout and also function as an Uninterruptible Power Supply (UPS).
  • It’s suitable for outdoor or indoor installation.
  • The inverter and any components other then the battery modules have a 5 year warranty.  The battery modules have a 10 year warranty when used for self consumption.

The number of companies in South Australia that can sell subsided Alpha ESS systems is rapidly increasing.  Last week there were two and today there are six.  I contacted Suntrix because they were one of the first and they were kind enough to tell me their pre-subsidy and post-subsidy prices for a fully installed Storion-SMILE-B5 GW with the following amounts of usable storage:

  • 5.5 kilowatt-hours:  $9,042 without subsidy, $6,192 after SA subsidy or $5,622 for concession holders.2
  • 11 kilowatt-hours:  $13,992 without subsidy, $8,292 after SA subsidy or $7,142 for concession holders.
  • 16.5 kilowatt-hours:  $17,220 without subsidy, $11,220 after SA subsidy.  (No change for concession holders.)

This makes Alpha ESS much cheaper than the alternative eligible systems from Sonnen3, but their warranty is not as good.  Note that even with the SA subsidy your home will need a high enough overnight electricity consumption and a large enough solar system for a battery to be cost effective.

Alpha ESS Storion-SMILE

Well, what do you know?  Alpha ESS has managed to make a battery system smile.  (Image:  Alpha ESS)

Company Information

Alpha ESS was founded in 2012 and its headquarters are in the Chinese city of Nantong.  Currently more than 10,000 of their residential and commercial battery systems have been installed worldwide, with thousands of them in Australia.  They have an office in Sydney and presumably will have one in Adelaide any second now.

The battery modules Alpha ESS uses are manufactured by the Chinese company EVE which stands for Energy Very Endure.4  This company was founded in 2001 and is a large manufacturer of batteries for Chinese electric cars and other purposes.  Their company song is awesome.

The Battery Module Is On The CEC Approved List

The Clean Energy Council has recently created a list of approved energy storage devices and the battery module Alpha ESS uses in their Storion-SMILE-B5-GW is right at the top!  There is only one reason why the CEC gave it the number one position and that is because the list is in alphabetical order.

CEC approved energy storage devices

If you want to see what other systems are on the little list, it can be downloaded from this page.  Being on the list does not mean a system will work perfectly without any problems, but it does mean it should meet Australian standards and be safe.  By safe, I mean safe in the way I have no problem typing this with my fingers only centimeters away from a potentially explosive lithium laptop battery  I also have no fear of putting a phone with a lithium battery into my pants or shoving it against my face.5  But while we usually consider them to be safe, laptop and phone batteries do explode on rare occasions so you can’t be 100% certain your battery system will be safe.  But hopefully you will be no more likely to die from a home battery exploding or catching on fire than you are from being killed by a short circuit in your air conditioner or a ceiling fan falling on your head.

There’s not a lot of money to be made in selling battery systems that kill people, but to be on the safe side you should only buy batteries that are on the CEC approved list.  If it’s not on the list I wouldn’t touch it with a 10 foot pole.  Not unless the pole was well insulated.

Problems With The Alpha ESS Website

Alpha ESS appears quite proud their systems can receive the South Australian Battery subsidy during the exclusive period that lasts until the end of this year…

Alpha ESS website

Goddammit Alpha ESS!  Despite what the screenshot above from your site says, you are only A provider, not THE provider.  Does Sonnen, the German company whose battery systems can also currently receive the subsidy, know you are saying stuff like this?  Trust me, you don’t want to go picking fights with Germans.  My grandfather lost a fight to some Germans and they took over his entire country.

While only the Storion-SMILE-B5-GW is available at the moment, there are 5 different battery systems in the image above.  On the page that is specifically about the SA battery subsidy they show 4 systems.  Each has a trio of brown, origami looking Australias above it, which make it look as though they don’t know where Adelaide is.  It instead seems to be emphasizing the middle of nowhere.  You need to be on the grid to get the subsidy and geographically-speaking, there is only grid in the south-east of the state.

Alpha ESS Storion-SMILE battery range

You can see on the image above it says the Storion-SMILE-B5-GW is a 5 kilowatt battery system which most people would reasonably mean it can supply 5 kilowatts of AC power.  But according to its inverter technical specifications, its maximum AC output is only 4.6 kilowatts.

Technical Specifications — Battery Module

Here are the technical specifications of the EVE battery module the Storion-SMILE5 systems use:

Alpha ESS Storion-SMILE-B5-GW battery module specifications

If you look at the weight, you can see at 65 kg the modules are pretty heavy.  A system with three of them may weigh even more than I do.

Technical Specifications — Inverter

Here are the technical specifications of the hybrid inverter in the Storion-SMILE-B5-GW.

Alpha ESS Storion-SMILE battery inverter specifications

Battery Chemistry

The battery modules are lithium iron phosphate, which is the safest type of lithium battery technology.  But just because a battery system uses the least dangerous chemistry doesn’t mean it will be the least dangerous system.  It will depend on how well it’s designed and how reliable its components are.  It’s like the difference between petrol and diesel cars.  Diesel is a safer fuel, but a petrol Volvo is always going to be less dangerous than a diesel trabant.

That said, until we have a better idea of who makes the safest systems, if safety is a major concern you are better off going with the safer chemistry.

Energy Storage Capacity

The EVE battery modules the Storion-SMILE5 uses have a nominal capacity of 5.7 kilowatt hours and can have a depth of discharge of up to 96%.  This makes the effective storage capacity of each module 5.5 kilowatt-hours.  As a system can have 1 to 6 modules the total usable storage capacity can range from 5.5 to 33 kilowatt-hours.  Currently only systems with 1 to 3 modules are on offer in South Australia.  These give usable capacities of:

  • 1 module = 5.5 kilowatt-hours
  • 2 modules = 11 kilowatt-hours
  • 3 modules = 16.5 kilowatt-hours

But if you want more than this and don’t mind paying extra for battery modules that won’t be subsidised, you should be able to get extra ones.


Unfortunately, the descriptions given on the Alpha ESS website don’t make it clear to the casual reader how much power the Storion-SMILE-B5-GW can provide.  The number “5” figures prominently in its name and their site they straight out say it’s a 5 kilowatt system:

Alpha ESS Storion-SMILE - 5kW?

Most people would quite reasonably conclude this refers to the system’s AC power output.  But if you look at the battery technical specifications above you can see its maximum charge and discharge rate is give as 56 A or 0.5C:

Alpha ESS Storion-SMILE charge and discharge current

This mean it can only charge and discharge at a maximum of half the battery’s nominal capacity of 5.7 kilowatt-hours.6 So a system with one battery module will only be able to supply around 2.85 kilowatts of continuous power.  But this will be DC power and not the AC power homes use.  If the inverter’s average efficiency of 97% applies then 2.85 kilowatts of DC power will be reduced to 2.76 kilowatts of AC power.

A battery system with 2 or more modules will be able to supply more power but it will be limited by the 4.6 kilowatt AC output of its inverter.

DC Coupling

As an all-in-one system the Storion-SMILE-B5-GW can be DC coupled.  This involves connecting rooftop solar panels to its built in hybrid inverter as shown in this illustration from the Alpha ESS site:

Alpha ESS Storion-SMILE battery DC coupling

If you are installing a new solar system this can save you the cost of a standard solar inverter and so the system may be better value than it first appears.  In this configuration the battery system can provide backup power during a blackout.

AC Coupling

If you already have a solar system installed it may be more convenient to AC couple the Storion-SMILE-B5-GW as shown below.

Alpha ESS Storion-SMILE battery AC coupling

With this arrangement the battery system will be able to function no matter what type of solar inverter is already installed or what the solar panel capacity is.  But if the solar capacity isn’t large you may have difficulty charging your battery.  Unless there are special circumstances it won’t be able to provide backup power in this configuration.


It is possible, although uncommon, to combine DC coupling and AC coupling:

Alpha ESS Storion-SMILE battery hybrid coupling

This could potentially be done where there is an existing solar power system you wish to keep but you want additional solar capacity to help charge your batteries.

Backup Power

When solar panels are directly attached to the Storion-SMILE-B5-GW’s hybrid inverter it is able to provide full backup and charge its batteries from the solar panels during the day.  It also functions as an Uninterruptible Power Supply, or UPS.  This means when a blackout occurs electrical devices that are able to draw on the power supplied by the battery should not have their functioning interrupted.

During a blackout the maximum amount of AC power the inverter can supply is 4 kilowatts.

When AC coupled the Storion-SMILE won’t be able to provide backup power except in the unlikely situation where the existing solar inverter is a hybrid that can allow the home to operate off-grid.

Weight & Dimensions

With 2 battery modules and 11 kilowatt-hours of usable storage the SMILE-B5-GW will be 180cm tall, 25cm deep, and 60cm across.  Or at least it is according to one set of figures from the Alpha ESS site.  According to another set it’s just a little larger.  Each additional battery module will increase its original size by one-third.

Alpha ESS Storion-SMILE-B5-GW dimensions

Each battery module weighs 65kg and the inverter is 58kg, so a system with 11 kilowatt-hours of usable storage should weigh 188kg.

Installation Location

The SMILE-B5-GW is able to withstand rain and can be located indoors or outdoors.  It is best to keep it out of the sun to prevent it getting too hot to operate.

Operating Temperature

The system is able to operate normally at temperatures from 0 to 40 degrees.  From 0 down to -10 degrees and from 40 up to 50 degrees the batteries will still be able to charge and discharge, but at a reduced rate.  In most of Australia reduced power output could be an issue during heatwaves.  And in some parts of Australia it could be an issue during coldwaves.

The Warranty

The Australian warranty can be downloaded from this page.  The warranty for the inverter and everything that isn’t a battery module is 5 years.  The warranty for the batteries is better and promises they will retain a minimum of 80% of their original capacity after 10 years, but only if certain conditions are met:

  • The system has an internet connection.7
  • The batteries are used for “self-consumption” only.

If the system isn’t connected to the internet, then the battery warranty will only be for 3 years and Alpha ESS says if you want to make a claim either you or the installer will have to arrange an inspection of the system at your own cost.  But under Australian Consumer Guarantees it is possible to claim for reasonably foreseeable damage and loss and this would include the cost of having a system that fails to operate correctly inspected.

While they don’t give a precise definition of “self-consumption”, presumably this means the battery is only discharged to meet household needs.  This strongly suggests the battery cannot be used as part of a Virtual Power Plant and still receive the full 10 year warranty.  When I mentioned this to ESS they told me that their battery systems were already being used as part of a Virtual Power Plant in NSW and they would update their warranty.  But as it currently stands now, it states that when not used for self-consumption:

This condition means if you don’t use the battery only for “self-consumption” and you cycle it an average of 80% or less of its nominal capacity per day, as many households are likely to do, then the warranty will last the full 10 years.  But if you cycle it an average of once per day the warranty will only last for 8 years.

I find it interesting that outside the “self-consumption” condition they will only provide a warranty equal to 2,920 cycles when the battery module’s datasheet states its cycle life is 10,000:

Alpha ESS Storion Smile battery cycle life

They have an asterisk next to it that says it’s “Under specific test conditions”, but that’s not much of an out.  No one buys a home battery  system to operate it under specific test conditions.  If they were confident their battery system would last close to 10,000 cycles, its warranty would reflect it.

As Alpha ESS has said they will update the warranty, if you get one of their systems, I strongly recommend checking if the warranty will be affected by joining a Virtual Power Plant.

They Should Make The Warranty 10 Years For The Entire System

Hopefully in the near future Alpha ESS will offer a 10 year warranty for the entire system.  At the moment the inverter could fail after 7 years and leave the owner to puzzle over if it would be worthwhile to pay to have the inverter replaced for the sake of batteries that will be out of warranty in 3 years time.  A full 10 year warranty will avoid these situations and make the decision to invest in a system easier.  This should increase sales.

Double Check What You Are Getting

I found the Alpha ESS website difficult to follow and confusing at times.  Because it’s not completely clear it’s important to double check with your installer that you are getting exactly what you expect and that it will suit your needs.  I expect that as Alpha ESS increases their presence in Australia their communication ability will improve.


  1. Yesterday I learned Alpha ESS will provide a system that will be called a “Goanna Battery“.  I suspect this will be the same or similar to their SMILE systems, but I don’t have any solid information on it yet — only marketing fluff.
  2. The SA battery subsidy is $500 per kilowatt-hour of total storage capacity up to a maximum subsidy of $6,000.  Low income earners such as pensioners and people receiving most Centrelink payments receive a subsidy of $600 per kilowatt-hour of storage up to the $6,000 maximum.
  3. Eguana Technologyies batteries are also eligible for the SA subsidy before January – but since they have flat out refused to tell us their prices when we asked, they can get stuffed.
  4. No, this is not a joke.
  5. But I make a point of NEVER licking any of the pictures of goats in bikinis that somehow keep appearing on it.
  6. The battery’s nominal voltage is 51.2 volts and when multiplied by the 56 A or amps it gives 2,867 watts.  The other figure, 0.5C, means the battery can provide power in kilowatts equal to half its total storage capacity in kilowatt-hours.
  7. In case you’re not aware the internet is a system for transmitting cat videos and pictures of goats in bikinis.  But lately its main use has been to complain about how bad the Fallout 76 computer game is.  No one seems to understand why such a lousy game was released, but with my degree in shonkology it seems obvious.  A competitor just released a game that cost over $300 million to make.  It wasn’t possible to put out a game that could compete with it on quality so they deliberately released a game that was so horrible everyone spent their time complaining about how awful it was instead of talking about how good their competitor’s game was.  They ripped off their customers and screwed over the competition at the same time.  That’s what computer game companies call win-win.
About Ronald Brakels

Many years ago now, Ronald Brakels was born in Toowoomba. He first rose to international prominence when his township took up a collection to send him to Japan, which was the furthest they could manage with the money they raised. He became passionately interested in environmental matters upon his return to Australia when the local Mayor met him at the airport and explained it was far too dangerous for him to return to Toowoomba on account of climate change and mutant attack goats. Ronald then moved to a property in the Adelaide Hills where he now lives with his horse, Tonto 23.


  1. Is there any limitation to these type of Lithium battery’s ability to discharge at peak capacity during cold days or nights, say temperatures at around 10 deg C or below? I live in Canberra and it can get cold on some days.

    • Ronald Brakels says:

      Hi Sam

      Lithium batteries (and some others) definitely can have problems charging and discharging when the temperature is below zero degrees. But this is not likely to be a problem for you. The mean temperature in the coldest month in Canberra is 6 degrees and the battery packs are really heavy at 65kg so if temperatures drop below freezing at night their thermal inertia should mean they’ll stay above freezing. And even if they fall below freezing the record low in Canberra is -10 degrees so they should always be able to provide some power. When the batteries are in use they produce a small amount of waste heat so that will help keep them warm. Basically I don’t think you really have anything to worry about. It is possible cold conditions could reduce their output at times but I don’t think the effect would be very noticeable in Canberra.

  2. So based on this:
    11 kilowatt-hours: $13,992 without subsidy, $8,292 after SA subsidy or $7,142 for concession holders.

    I think I would prefer the battery in Solar Quotes battery comparison table which is the Alpha-ESS ECO S5

    Listed at a cost of $12,375 for 14.4kWh (12,96 usable)

    I don’t know if the prices quoted in the article include installation – even if they do (which I doubt) then I think the ECO S5 would be a much better deal. It seems Alpha no longer makes the ECO S5 which is a shame because it was much more to SMILE about.

    • Ronald Brakels says:

      Hey Mondo

      I spoke to Alpha ESS today and they say they only have a few ECOs left in stock and will soon be switched over to their new SMILE systems.

  3. I was very excited to read this post today and asked Suntrix to attend and quote on a solution for my house. They said that they required a fully refundable $200 deposit before they would make a booking to attend.
    They emailed me a quote which will be confirmed during the inspection BUT the $200 deposit is only refundable in the event that:
    1. It is determined during my home visit that a battery is nor suitable: or
    2. I am unable to secure the subsidy and additional finance (if required); or
    3. Additional costs are identified during the site inspection which result in an increase in the price quoted.
    Given that the quote in my opinion is not based on a proper needs assessment I see the $200 being a fee for time to attend and assess. Rather than assume that Suntrix is the only supplier for my needs I will look at alternative suppliers.

  4. Doug Mason says:


    Can you comment on whether the Alpha-ESS SMILE5 battery system takes over all monitoring of PV + battery to exclusion of other monitoring services, or whether other monitoring systems can co-exist with the Alpha-ESS battery after battery installation?

    For example, my PVs have Enphase microinverters which are monitored by Enphase Enlighten web-based system (using Enphase’s Envoy-S sitting behind my meter box). Would the Enphase system continue operation with addition of an Alpha-ESS battery, or would it be rendered useless (if so, the firmware of my Ephase microinverters could not be upgraded by Enphase).

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