sonnenBatterie Evo. Finally! A Decent Battery From sonnen.

sonnenBatterie EVO battery review

The sonnenBatterie Evo. You could install it in the middle of a field – but think of the voltage-rise!

Just the other day, Finn was having a whinge about sonnen batteries.  He mentioned a few problems the current sonnenBatterie Eco has:

  • You can’t install it outside without a protective cabinet.
  • Its power output is low compared to similar-sized batteries.
  • Backup power is an expensive optional extra.
  • Even with the backup option, it can’t charge from rooftop solar panels when the grid is down.
  • It’s expensive.

But now, less than a week later, sonnen has launched their new battery — the sonnen Evo.  It mostly addresses these concerns — except for the last one.  Sonnen gave no pricing information at the launch.  But as Sonnen has always positioned itself as a premium brand, it’s not likely to be cheap.  

Update December 7th 2021: Sonnen has told me they expect the sonnen Evo to cost around $14,000 including installation, which is a much better price than I expected.

The sonnen Evo has the following features:

  • 10 kilowatt-hours of usable storage.
  • 5 kilowatts continuous power. 
  • AC coupled — this lets it work with any solar power system or no solar system.
  • Built-in backup can provide 5 kilowatts of continuous power.
  • The battery can charge from solar in a blackout, but only if the solar power system is 6 kilowatts or less.
  • A warranty that will last any normal household a full 10 years, while retaining a minimum of 80% of original capacity.  This is much better than most lithium solar battery warranties.

Update December 7th 2021: Sonnen has told me the sonnen Evo can be used with Virtual Power Plants (VPPs) other than those offered by sonnen and not just their own, as I originally had written.

Sonnen says the Evo battery should be available in early 2022. 

What Is sonnen?

Sonnen is a German company founded in 2010 that’s been making home battery systems for over 11 years.  They supplied the first modern home battery systems for on-grid use rather than off-grid.  They were originally called sonnenBatterie but shortened it to sonnen, so they don’t have to pay as much when sending a telegram.  Their name doesn’t start with a capital letter. That’s because, before 1990, Germany had two capitals and reduced the number of capitals in the German language to compensate.  

The sonnen Evo also has a longer name, the sonnenBatterie Evo, but try not to use that when sending a telegram.

Imported From Germany

The sonnen Evo is imported from Germany.  Sonnen won’t assemble it in Adelaide despite all the support they received from the South Australian government to set up a factory here.  At the battery launch, sonnen said they would keep that capacity for “future use”.

I could have told the South Australian Government not to spend valuable resources attempting to set up battery manufacturing in South Australia.  (In fact, I think I did.)  While they should welcome any solar battery manufacturer who wants to set up shop here in SA, they should treat them the same as any other business.  This is because we live in a world of limited resources, and it’s not possible to give more resources to one business without reducing the resources available for everyone else. 

Governments should stick to what they are good at which is punishing bad things, not promoting good things.  This is why the police are in charge of catching bank robbers, and families are in charge of Christmas presents. 

Components Made All Over

At the launch, they didn’t say where the sonnenBatterie Evo’s battery modules are manufactured.  But unless they’ve changed their ways, sonnen will source them from two high-quality battery manufacturers in China1.  The battery inverter probably also isn’t made in Germany, but elsewhere in Europe.  Other components could come from all over the place.

This is not a problem.  These days a successful international company can successfully source high-quality components from around the world.  Companies that pull it off should be boasting about it, not hiding the fact.

sonnenBatterie Evo Tech Specs

Currently, there’s no datasheet available for the sonnen Evo. 

Update December 7th 2021: The datasheet is available here.

But sonnen presented slides with technical information at the online launch, and I’ve scattered them through this article.  Here’s one giving an overview:

sonnenBatterie Evo technical specifications overview

Battery Capacity

The battery has a total (or nominal) capacity of 11 kilowatt-hours.  But to protect it from capacity loss, its maximum depth-of-discharge is around 91%.  This makes its usable storage capacity 10 kilowatt-hours.  It should stay reasonably close to that amount within its warranty period, as sonnen promises it will maintain at least 80% of its original capacity. 

If more storage is desired, up to three sonnen Evos can be used for a total of 30 kilowatt-hours of usable storage when new.  It’s possible to add even more if a device from SwitchDin or another manufacturer is used to manage them. 

Update December 7th 2021: Sonnen says it’s not necessary to use SwitchDin to go over 30 kilowatt-hours of storage, but it can provide benefits.

Evo Battery Modules & Chemistry

The sonnenBatterie Evo has two 5.5 kilowatt-hour modules.  Here’s the information sonnen presented:

sonnenBatterie Evo battery module specifications

Lithium Iron Battery Chemistry

The battery chemistry is lithium iron phosphate (LiFePO), or just lithium iron for short.  This is the safest lithium battery chemistry.  This doesn’t mean batteries using this chemistry are safe; it just means it is easier to make lithium iron batteries meeting a high standard of safety than other types.  If a battery module manufacturer and/or battery system producer don’t ensure they are safe, they won’t be.  But I definitely expect sonnen batteries to be low risk.  They have a good track record of not burning down homes in Germany. 

Lithium iron batteries don’t use cobalt.

At the launch, they made it sound like they were doing us some big favour by not including cobalt because:

  • It’s toxic.
  • It may not be mined ethically.

But using iron instead of cobalt for stationary storage is both cheaper and better.  While cobalt2 can allow batteries to be more compact, sonnen would have to be drongos to use cobalt in a battery made to be installed outside. 

sonnenBatterie Evo Power

The sonnen Evo can supply 5 kilowatts of continuous power.  Like pretty much all lithium batteries, it can also – briefly – supply more.  Its 5 second surge capacity is 7.2 kilowatts, and it can supply 8.6 kilowatts for one-tenth of a second. 

If the battery is new with 10 kilowatt-hours of usable energy storage, it will provide 5 kilowatts of power for up to 2 hours. 

AC Coupled

The sonnenBatterie Evo is AC coupled.  This means it operates independently from the solar system, so it doesn’t matter what type of inverter your solar power system has.  It can also be installed in homes without rooftop solar panels.   

sonnenBatterie Evo power unit specifications

This is the sonnen Evo’s power unit, which includes the battery inverter.

Sonnen Evo Efficiency

At the launch, we were told the sonnen Evo’s inverter efficiency is 94.4%. But this is not the same as the battery system’s round trip efficiency, as it only represents energy going one way.  If we assume the efficiency is the same when the battery is charged and discharged, the inverter’s round trip efficiency would be 89.1%.  But there are also energy losses from the batteries, electronics, and cooling fans.  This means the total round trip efficiency of the sonnenBatterie Evo will be significantly less.  Possibly much less.

I asked what the round trip efficiency was…

But sonnen didn’t answer the question. 

In the latest report from the Canberra Battery Test Centre, the sonnen Eco was found to have a round trip efficiency of about 80%.  The sonnen Evo may do better than this but, unless I hear otherwise from Sonnen, I would not expect it to be above 85%.

Operating Temperature

The sonnen Evo’s operating temperature was given as -10ºC to 50ºC.  This is a good range for Australia.  Some batteries conk out at 45ºC, which is a problem because severe heatwaves are when power is needed most.  So far, no Australian capital has ever hit 50 degrees, but it may only be a few years before this changes.


Sonnen gave no information on noise output.  The sonnen Evo has cooling fans, so I don’t expect it to be completely silent when they’re operating.  But I do expect it to be fairly quiet.  After all, there are a lot of sonnenBatteries inside homes.   

The cooling fans are claimed to last 60,000 hours.  As they may only be used a few hours a day, if that’s true, they should have no problem reaching the end of their warranty. 

Outdoors Installation

The system’s Ingress Protection rating is IP56 which makes it suitable for outdoors installation.  This rating means it’s able to resist strong jets of water.  I definitely don’t recommend hosing it down, but if someone did do that, both the hoser and the hosee should be fine. 

This IP rating is a big improvement on sonnen’s previous batteries, which had to be installed indoors or in a separate expensive, industrial, steel cabinet.

EVO Battery Dimensions And Weight

The image below gives the sonnenBatterie Evo’s dimensions and weight:

sonnenBatterie Evo installation specifications

The system is made to sit on the ground and can’t be wall-mounted.  We weren’t told what kind of clearances around the unit may be required.

Sonnen EVO Backup

Unlike their previous home batteries, where backup capability was an expensive additional extra, every sonnen Evo has backup built-in.  It can supply 5 kilowatts of continuous power during a blackout, the same as in normal use. 

But it will only be able to charge the battery in a blackout using solar power if the solar inverter is 6 kilowatts or less on the same phase as the sonnen Evo.  

The battery has a black start capability that you can use during a blackout (if you have 6 kilowatts or less of solar inverter capacity on the backup phase).  If the battery is flat, and the panels are producing enough power, a button on the unit can be pressed that will cause the battery to start charging.

When a blackout occurs, the change over to battery backup won’t be instantaneous.  Sonnen said the delay should be under a second. 

sonnenBatterie Evo backup specifications

Backup Power To 1 Phase Only

The sonnen Evo is a single-phase battery. Most homes only have single-phase power, so this is not a problem for them.  For homes with three-phase power, it’s also not a problem in normal use. 

As far as your electricity bills are concerned, it will operate the same as if your home was single-phase.  But during a blackout, the sonnenBatterie Evo will only supply power to the phase it’s connected to.  This means all your essential loads will need to be on that phase.  It also won’t be possible to run three-phase devices, such as many large air conditioners or three-phase solar inverters from backup power.

If a property has three-phase power, it is possible to put a sonnen Evo on each phase, but obviously, this won’t be cheap. 

Excellent Warranty

The warranty document isn’t available yet, but sonnen said the warranty is 10 years or 10,000 cycles — whichever occurs first.  As no normal household will ever come close to cycling the battery over 1,000 times a year, the warranty should last the full 10 years.  It also promises the battery will retain at least 80% of its original capacity.  This is excellent. 

Some battery warranties won’t last a household a full 10 years if they cycle it an average of one per day, and most lithium battery warranties only promise they’ll retain 70% or 60% of their original capacity. 

Virtual Power Plants (VPPs) allowed

Update December 7th 2021: Sonnen has told me the sonnen Evo can be used with any VPP and not just with sonnen’s VPPs as I had originally written.

sonnenBatterie Evo Price

At the battery launch, sonnen gave no prices, but this One Step Off The Grid article suggests a sonnenBatterie Evo will cost around $14,000 before installation.  While sonnen says the installation will be easy, it can still easily add a couple of thousand dollars to the cost of a battery.  This is because it has to cover not just the cost of installing it but also after-sales service.

Update December 7th 2021: I’ve been told by sonnen they expect the installed cost of the sonnenBatterie Evo will be around $14,000.  This can depend on the property’s characteristics.  This is a much better price than I expected.  

Evo A Big Improvement

The sonnen Evo is clearly a large improvement over the company’s earlier offerings thanks to:

  • Ability to be installed outdoors.
  • An increase in continuous power output to 5 kilowatts.
  • Built-in backup.

So if you have 6 kilowatts or less of solar inverter capacity or less on the phase you want backed up3 then the sonnenBatterie Evo may be a good choice for those who don’t mind paying a premium for a well-built battery system with a good warranty from a company with the longest track record.


  1. It’s common practice for companies to have more than one supplier for vital components. Otherwise, one factory fire or bribery scandal (in some countries, officials are scandalized if they don’t receive bribes) can wreck your business.
  2. Cobalt is German for goblin.  This is because, a long time ago, German miners used to blame cobalt contaminated silver on goblins.  But they haven’t done this for weeks now.
  3. Or don’t mind if the battery can’t charge from solar when the grid is down.
About Ronald Brakels

Ronald was born more years ago than he can remember. He first became interested in environmental matters when he was four years old after the environment tried to kill him by smashing fist sized hailstones through the roof of his parents’ Toowoomba home. Swearing revenge, he began his lifelong quest to reduce the harm the environment could cause. By the time he was eight, he was already focused on using the power of the sun to stop fossil fuel emissions destabilizing the climate. But it took him about another ten years to focus on it in a way that wasn’t really stupid


  1. Very interesting. On the latest battery testing results didn’t Sonnen perform the best?

    Also, aren’t the batteries they use Pylontech?

    Lastly, These specifications are a long way behind the newer Power Cap graphene supercapacitors which have a 20 yr warranty with zero degradation, and virtually zero risk of fire. (They do have a little bit of lithium in them to reduce any self discharge)

    Have you seen, tested or investigated these?

    • Joseph King says

      This Pylontech sounds interesting. I had a quick Google and if I have read the stats correctly I could have a battery that was twice the capacity of the our 10kWh LG for the same price. I would have liked that.

    • Ronald Brakels says

      If you are referring to the Canberra Battery Test Centre, their sonnen Eco developed a fault and so didn’t do well:

      Last time I was present when sonnen gave information on how they sourced their batteries they didn’t say who they got them from, but — if you believe the warranty — sonnen uses great batteries and pylontech are great batteries…

      So far I’ve not been impressed with the prices or real world performance of any batteries described as supercapacitors. They may improve, but I’ll only believe independent testing of full modules, not individual cells.

  2. Would it be acceptable if i chose to use Sonnen rather than sonnen? I guess they want their name to stand out and capitalising it does not do that in the German language, but here in Australia we have a different system.

    This is an interesting development (assuming the hype of the presentation is matched in reality) as it will presumably, and hopefully, instigate some serious competition to bring about a more realistic pricing structure, among other things.

    How arrogant of Sonnen to attempt railroading consumers into using their version of VPP. But they may choose this path just as we consumers may choose our path.

    Here in WA there are precious little choices when it come to electrical energy and further restricting choices probably will not work so well in our market. But why should Sonnen care? WA is a small market they can ignore. Yes, and we will ignore them.

    eePhilosopher Ronald Brakels will no doubt have interesting and insightful perspectives about this.

    ee = electrical energy

  3. Trevor Jolly says

    In re. the “3. Assume positive intention.”, I can’t help noting the lack of ‘positive’ information with which to make valid assessments. ie. PRICES of comparative products. Personally I’m a fan of quality suitable (agm/etc??) batteries-banks. I’ve had nearly 40 years of experience, and watched the technology/warranties*/etc. improve beyond measure and the prices drop almost as dramatically. AND there are no ‘conditions’ applied by the manufacture. In fact most of the hi-tech junk inherent in ‘modern’ batteries is unnecessary and only provides scope for more things to go wrong. Finally, what I’d REALLY like to see are details (photos? prices? etc) of the systems Ron and Finn/others have installed. As said previously: the real ‘value’ of this (or anything else) can only be assessed by comparison with (a) what’s available and its cost, and (b) exactly what EACH INDIVIDUAL needs. (eg an air-conditioner vs. a small desk fan.)
    * How do 12VDC deep-cycle AGM LA batteries with an unconditional 3-year warranty (expect over 5 years, properly treated) @ UNDER $2 per AH sound. (That’s a whisper over $1500 for a 10kW bank (of them) OR at the price put in TWO, balance usage between them and keep the DOD at, say, 15%. How long they last will depend on varying factors, including ‘cycling’: THAT can be pre-decided by the owner (I personally do most of what I want with a consumption of between 3&4 kWh per day, and compile my battery-bank accordingly. The GOOD news is that their IS life after death: completely worn out batteries can simply and cheaply be rejuvenated. (Not as good as new, but well worth the small effort.) A final comment re. the (often ‘required’) ancillaries: NOBODY needs inverters, chargers, etc.etc. that cost ridiculous sums when cheap little units (applied to different needs) will do the job for a small fraction of the cost. eg. a 300-Watt inverter ($125 at ‘Autocheap’) will run the lights AND a medium-sized TV in a not-too-large household. Another such will run a couple (or
    three) of computers. Reducing usage (switching off unused lights etc.) can make a HUGE difference. (I’ve long found a 2kW generator will run short-term things like microwave ovens, etc. for pennies a week) My typing finger’s getting sore, so will end here. But the options are out there. I think sharing information and ideas has a great deal more merit that haggling-over/pushing the latest gee-whiz ooh-aahs.

    • Des Scahill says

      Reply to Trevor Jolly

      Hi Trevor,

      I like your comment that “In fact most of the hi-tech junk inherent in ‘modern’ batteries is unnecessary and only provides scope for more things to go wrong.”

      The law of diminishing marginal utility is alive and well into today’s consumer orientated society.. So much so its become ridiculous at times.

      • Trevor Jolly says

        Hi Des. In the world in which I grew up EVERYTHING was hands-on and the KISS principle prevailed. I do have a high regard for modern developments in technology, medicine (at my age that matters), and many other things. But my personal line-in-the-sand lies where individual CHOICE is sacrificed to somebody else’s idea of ‘what’s good for you’. (eg electronic ‘management systems’ without which the ~over-expensive!~ product won’t work.). And that applies to basics, too. Pet hate just for the moment are ‘must-have’ ‘Anderson plugs’, which can do NOTHING that I can’t achieve with a couple of short bits of copper-pipe. Not only can one get a better connection, at ANY voltage/amperage, and very simply incorporate an appropriate fuse, but one can also save money, time and efficiency on conductors. And the kicker? Y’know what you’ve got, how to monitor it, and (when necessary) how to fix it. The idea that your battery (as opposed to a multi-battery ‘bank’) needs to be delivered/sited with a forklift, and MUST be installed by a ‘qualified expert’, and then monitored/governed remotely by some stranger/’algorithm’, strikes me as abhorrent. All the best.

  4. Warwick Duncan says

    I don’t actually give a toss about sonnen batteries but that was so delightfully written I ended up reading the entire article. Nice work Ronald!

  5. Geoff Miell says

    The sonnen Evo’s operating temperature was given as -10ºC to 50ºC.

    Is there any information on low (or high) ambient air temperatures reducing energy storage capacity and output power performance?

    Is power backup ‘seamless’/’uninterruptible’ or is there a time delay to switch over?

    • Ronald Brakels says

      Derating at higher temperatures is a definite possibility. I’d say it’s likely as we are just given it’s operating temerature without any qualifications. The switchover to backup is not seamless and sonnen says they hope it will be under one second.

  6. Michael J Keaney says

    We still seem to be stuck at around $14K for a 10 kWh battery.

    Where I live, I pay 22.5c per kWh and can export for 9.5c per kWh.

    As I have a 6kW solar plant, it is reasonable to assune I can fully charge and discharge the whole system every day of the year.

    So basically I can store $1.30 worth of my free electricity every day, for 10 years. That’s not even $5K worth of savings, how do I justify the other $9K.

    It seems that batteries have long way to go before they are going to become the renewables nirvana that is so ofter promised, or am I miising something here?

  7. Brian Crook says

    Curiosity rears its head. Is it known why the battery blackout charging requires the solar inverter to be 6 Kw or less?

    • Tim Latimer says

      Hi Brian – this limit is for solar installed on the batteries back up circuit. The reason it is 6kW is during a grid blackout the sonnen system has to manage the power output of the AC coupled inverter, as excess energy is unable to flow to the grid. The energy being produced can be used to either power the household demand and/or charge the batteries. The limit removes the risk of having too much power without anywhere for it to go.

    • Further to what Tim said, this issue applies to all AC coupled batteries that work in a blackout and support grid connected solar inverters in a blackout. As Tim said, when isolated from the grid, the battery needs to be responsible be balancing supply and demand in the home. Grid tried solar inverters are designed to just pump out as much power as there is sun, on the assumption that excess just goes to the grid. When not grid connected any more because of a blackout, the battery (which is the devices that has isolated you, and pretended to be the grid so now needs to take responsibility for the issue it created), needs to manage that excess power. When you have more solar output than household loads the battery manages this as follows :-

      1. If the battery is not full, it can absorb that extra power by charging the battery.

      2. when there is more solar power than the household needs, and the battery can absorb charging, the battery can raise the frequency slightly, which triggers a mechanism in all Australian approved grid tied solar systems where on high frequency they must either shutdown or throttle their output.

      The issue with item number 2) above is that this does not happen instantly, and takes time. So to avoid voltage spikes etc in the home etc, in the very short term we can only rely on item 1) above. So the backed up solar can’t safely exceed the capacity of the battery to charge (absorb excess power), for long enough for it to be able to signal the solar to slow down, and for the solar to actually throttle.

      So this limit, is typically dictated by the specification of the battery charger to absorb power charging the battery.

      If you have an AC coupled battery vendor, who does not specify this limit, I would have significant alarm bells ringing that they “don’t know what they don’t know” and I would not buy it until they could explain how they manage this problem.

      When Tesla started selling the PW2 here, they were not aware of this issue, and initially told people including myself that there was no limit, and they could support any size solar system. But in subsequent discussions I had with senior engineers there, they eventually realised the problem, and now they have a 7kW limit.That is the peak charging capacity of the PW2. I would assume it is likely that sonnen have a slightly lower peak charging capacity, or are being a little more conservative to help better ensure they can further reduce the risks of power spikes.

      It is not unlikely they have taken a more “conservative” approach, by the fact that they are only aiming for a switchover in the seconds range, rather than Tesla’s often sub second changeover (though this could also just be that this is a simpler and cheaper implementation). While quicker changeover is “nice”, so you have less disruptions during changeover (ie your computer does not shutdown and reboot), it is not without its challenges in terms of managing excess power. The short “break” for the sonnen, is more likely to ensure that the solar shutdown, at least for the changeover. This reduces the chances of a voltage spike if the home isolates when there is very low home loads + battery is 100% full with limited ability to absorb excess power, and solar is running 100% flat out. With the PW2s quick changeover, the solar might be still running and this could possibly cause voltage spikes if Tesla have not ensured there is enough capacity to absorb this for a short period of time (which they might have done or they might have been prepared to just live with it on the basis that it is a rare event and they think they can get away with that).

  8. Do you have any more insights to this :-

    “If a property has three-phase power, it is possible to put a sonnen Evo on each phase, but obviously, this won’t be cheap.”

    Eg :-
    1. if you install 3 batteries, 1 on each phase, does this give real 3 phase support (ie phases are all in sync and thus you can drive real 3 phase loads and things like 3 phase solar inverters).

    2. Can it support 3 phase solar inverter.

    3. Can it support single phase inverters on the 3 phases.

    AC coupled single phase batteries on all phases can be a can of worms, with a lot of gotcha’s in implementation. Particularly if they want to support solar in a blackout, as I suspect is pretty important blackout protection is one of the main reason to install a battery that in all likelihood is too expensive to ever make a payback. 1 big gotcha is the fact that for AC coupled batteries that support solar in a blackout, probably use frequency shifting to control solar output. This tends to cause lots of problems that are not easy to solve unless the system is designed from the ground up to get around these problems. For example, because if it support solar in a blackout, it likely uses frequency shifting. If it is a single phase battery, this shifting very likely happens at different rates at different times on the different phases because of different loads and generation on the different phases. If this happens and the 3 phases get out of phase, then it clearly can’t really support 3 phase loads and solar inverters. Because of this, people like Tesla only support PW2 backup on 1 phase, even though you might have a PW2 on all phases.

    There would be ways around this. For example, if the “single phase” batteries are interconnected (probably via DC), I guess there would be the possibility of shifting power between phases to solve of of these issues. ie this would allow excess power from solar to be absorbed by whatever battery has capacity and reduce the need to throttle solar on the different phases at different rates. But to date, I have not seen any AC coupled batteries that implement this.

    Also, do you know if there is any ability to charge this battery with a generator if needed in an extended blackout?

  9. Anne & Brian Crook says

    So if one has a large Endphase system, you cannot solar recharge the Sonen Evo during a blackout?

    • Ronald Brakels says

      As long as there are less than 6 kilowatts in total of Enphase microinverters on the phase the sonnen Evo is on, it will be able to charge from solar in a blackout.

    • I know nothing about this battery. But I do know a bit about AC coupling and Enphase systems. And the answer is probably a bit complicated.

      The 1 word answer is that, yes, you should be able to get the enphase solar to work in a blackout. But the implementation of this might be a lot more complicated than 1st meets the eye depending on your circumstance, so you probably should discuss this with a reputable installer with good skills in Enphase and AC coupled batteries.

      But on face value I will give you a little more detail. If you are all single phase and below 6kW, it should be trivial and no different to any other solar inverter.

      If it is single phase, and above 6kW (as it sounds like you might be), I suspect you will still be able to get it going. You might just need to get someone to reorganise you enphase strings a little so you can have 6kW on the backed up side of the battery, and the rest on the grid side. In this way the 6kW or less on the backed up side of the battery should still work in a blackout, but the rest will shutdown with the grid (which is what you want to avoid exceeding the specification of the sonnen). In fact, if you have a large enphase system, you might already have the strings broken down, and coming to multiple breakers in the switch box. If this is the case, and one of the strings is 6kW or less, it should be trivial for the sparky installing the battery to do this. If there is not 6kW or less string, it might require a little more work, but I would be confident the right installer should find the way forward for you.

      But where it gets more complicated if you have a 3 phase enphase system. But let me assure you, with the right installer, and right help you should be able to get this working with solar on 1 phase. But out of the box, it probably won’t work unless your installer gets a very specific profile that is NOT the default installed here in Australia. If your enphase system is very old with the original Envoy, you might dodge this bullet. But if it is remotely new (ie certainly anything installed after 2016), you will no doubt have the newer Envoy-S which has some extra “functionality” that you will need to work around.

      The problem with 3 Phase is to comply with AS4777.2015 rules for 3 phase micro systems which required these systems to totally shutdown if there was a loss of power on 1 phase. So the system monitors for this, and if it detects a loss of power on any phase, it shuts down. This will happen, even although this type of AC coupled battery creates its own microgrid, and keeps 1 phase up. The enphase micros on that phase can’t start for the single reason the other phases are down. But there is a workaround. You need to get your installer to install a profile which disables this feature. Once you get that, you should be able to keep the enphase inverters on the backed up phase up and running.

      But please note, that certainly when I got this sorted out some years ago, the level of knowledge about this within the installer community, and even with the people I could talk to at Enphase was not good. And i could believe it might be hard to find people that understand this issue. So there is some chance it might not be easy to find people who understand these complications. But hopefully with more AC coupled batteries out there these days, hopefully it is better understood.

      My advice to you if you want a battery, make sure your installer commits to delivering you a solution that will support solar in a blackout. And then when they have finished the install, test it yourself before you pay them.

  10. Robin Memory says

    A question on charging the battery in a blackout please Ronald. (And thanks for the great article) . We have 8.5kW of solar on two arrays. Could I turn off the smaller array to leave 5kW being used only, and therefore keep charging the battery during a blackout? ( I realize that I would lose the benefit of the other 3.5kW being provided to the house). Thanks

    • Ronald Brakels says

      My understanding is that would technically work, but it may not be considered safe to have the battery configured to charge from solar if there are more than 6 kilowatts of solar inverter capacity on a phase. The warranty may not allow it.

  11. Craig Worland says

    I have today been given a quote in perth of $12,490 for the Sonnen evo.

    My issue is this battery does not seem to like working in a blackout.
    And has what appears to me to be a very poor quality inverter if its efficiency is 80 to 85%


    My installer says Evo not available atm due to compliance issues.
    Anyone received their battery, or confirm delay?

    • Tim Latimer says

      Hi Paul,

      Tim from sonnen here. I can confirm that we are waiting on the certification by the clean energy council. This is the final step in the certification process.

      Good news is the product is in the country and ready to go out to installations as soon as approval is complete.

      Thank you,


  13. Thanks for your response Tim.
    Hopefully before Spring!

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Please keep the SolarQuotes blog constructive and useful with these 4 rules:

1. Real names are preferred - you should be happy to put your name to your comments.
2. Put down your weapons.
3. Assume positive intention.
4. If you are in the solar industry - try to get to the truth, not the sale.
5. Please stay on topic.

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