Is The Budget Sungrow Battery Any Good? I Installed One To Find Out…

Recently, I decided to retrofit a 12.8 kWh Sungrow battery and hybrid inverter to a 6.6kW solar system on a rental unit I own. The video above is a deep dive from start to finish, but if you don’t feel like watching, here’s a summary.

Why A Battery? And Why Sungrow?

Why a battery? I wanted lower electricity bills and backup. For many years, I had a generous 22 cent feed-in tariff from AGL. They recently let me know they were dropping it to 6 cents.

When it comes to home batteries, lower feed-in-tariffs = higher battery savings. With a 46c usage and a 6c feed-in-tariff, my best-case savings would be $5 per day, or $1825 per year. That would pay back the $14,000 retrofit in about 8 years.

In practice, I’ll save much less because that number is predicated on fully charging with solar every day and fully discharging every night. That won’t happen. The 6.6 kW solar won’t fully charge the battery every day of the year, and the AirBnB tenants won’t drain the battery every night.


Sungrow battery and inverter

The Sungrow battery and inverter that I installed

Why a Sungrow? Installers rave about them, and Australian Sungrow battery reviews are mostly excellent too. Despite being at the budget end of the spectrum, they are reliable, easy to commission and control, and the monitoring works well. The specific models installed were:

  • SH5.0RS  Sungrow Hybrid 5.0kW Residential Single-Phase Inverter
  • SBR128 12.8 kWh modular battery (4 x 3.2 kWh modules)
  • S100 Sungrow single-phase energy smart meter

Why Choose Sungrow Over The Tesla Powerwall?

Unlike the Tesla Powerwall, with a fixed 13.5 kWh per battery, the Sungrow is modular and can be expanded in 3.2 kWh increments.

The Tesla Powerwall is the most popular battery in Australia. I chose Sungrow because it offers a similar amount of storage for $2,000 to $3,000 less – and because I already have a Powerwall on my house and wanted to try something different. At SolarQuotes, we won’t accept free review hardware from manufacturers because my experience is corporate marketing departments always bitch and moan if your review is not a puff piece. So we buy the hardware we review. Cost of buying your own gear to review? Expensive. Independence from corporate marketing types? Priceless.

Also note that if you buy a complete solar + Sungrow setup all at once (as opposed to retrofitting), you can get a 6.6kW system + Sungrow battery for around the same price as just a Tesla Powerwall.

Why Replace My Fronius Inverter?

Sorry Fronius fans!

To retrofit the Sungrow battery to my existing system, I decided to replace the six-year-old Fronius inverter with a Sungrow hybrid inverter. The Sungrow inverter handles both the solar and the battery.

Fronius inverters get rave reviews, so why replace it? I could have kept the Fronius and installed the Sungrow next to it, and AC coupled the battery, the Fronius managing the solar while the Sungrow handles the battery. But a Sungrow-only system keeps things simple from an installation and monitoring perspective.

Advantages of replacing the Fronius with the Sungrow:

✅ Keeps things simple

✅ Less stuff on the wall

✅ DC coupling is marginally more efficient

✅ Fresh warranties

Disadvantages of replacing the Fronius with the Sungrow:

❌ Less redundancy if the inverter fails

❌ Removing a perfectly good inverter.

❌ The solar and batteries can only contribute a maximum power of 5kW total to offset the home’s power consumption. An AC-coupled system could provide 5kW from the solar and 5kW from the battery concurrently.

❌ The battery was installed by a different installer to the solar. If there’s an issue with the solar system, it is now half installed by two companies, making things interesting. Tip: it’s usually best to get the original installer to do the battery too, In this case, the original installer did not supply Sungrow.

And for those concerned about e-waste, a viewer bought my Fronius to replace a broken unit. $500 of beer tokens is always appreciated.

Bye Bye Solar Analytics Hardware

The old Solar Analytics hardware

I replaced my old Solar Analytics hardware with the Sungrow smart meter.

The new Sungrow monitoring hardware. More room in the switchboard! And, don’t worry: the hole was covered up before the system was signed off.

Because Sungrow integrates with Solar Analytics software over the internet, I could have Sungrow monitoring and Solar Analytics on the same system. If you want to see how that turned out – read this detailed post:  Solar Analytics Integrated Review: Better Than Sungrow Monitoring?

What Will My Sungrow Battery Back Up In A Blackout?

In terms of backup, I didn’t back up my entire flat because the Sungrow battery has a 25 amp limit – which is around 35% of a normal house supply. Instead, I just backed up essential circuits – lights, fridge, and a few general-purpose outlets (GPOs).

Very important to have vegemite on toast in a blackout situation.

The Nitty-Gritty Of Replacing The Inverter And Expanding The Sungrow Battery

You can buy a cover for the bottom third of the Sungrow if you don’t like to look at wiring

Installing the hybrid inverter on the wall and placing the batteries were simple enough. Wiring the battery to the hybrid inverter required only DC power, earth, and comms connections to communicate with the battery management system (BMS).

Moreover, adding more storage capacity in the future is a straightforward task. The installer promises me that they remove the top unit and stack on another unit. Each additional battery module increases the storage by 3.2 kilowatt-hours.

Testing the System

Following the six-hour installation, I conducted a series of tests with the installers. We confirmed the system’s functionality, ensuring the battery charges when there’s more solar power than the unit’s usage and discharges when the unit’s power consumption exceeds the solar generation.

We also tested the backup function by disconnecting the unit from the grid, and we were happy to see that the power supply to the essential circuits remained uninterrupted.

Finishing up

The final result of my installation

The end result – a schmick new inverter and battery on the wall.

Overall, the retrofitting process was painless. This project gave me a firsthand experience with Sungrow batteries and inverters, which, this far,  have lived up to the rave review from installers. The Sungrow inverter and battery combination is worth looking at for anyone considering retrofitting a home battery. And if you are buying solar and batteries together, it’s even better value.

The one downside is the limited backup capacity. If you need to back up your whole house – look at a system with more backup grunt.

Over the following year, I want to real-world test two particular features of the Sungrow:

  • Integration with SA’s solar sponge tariff. How easy is it to control the battery to charge on super-off-peak daytime grid electricity on crappy solar days?
  • Can the Sungrow charge overnight on the off-peak tariff to get through the early morning peak?
  • How easy and affordable is it – in practice – to add battery modules?

Keep an eye on the blog for updates.

About Finn Peacock

I'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and the founder and CEO of I started SolarQuotes in 2009 and the SolarQuotes blog in 2013 with the belief that it’s more important to be truthful and objective than popular. My last "real job" was working for the CSIRO in their renewable energy division. Since 2009, I’ve helped over 700,000 Aussies get quotes for solar from installers I trust. Read my full bio.


  1. I’m very happy with my Sungrow battery. Started out with a 4 module SBR128 about a year ago and just doubled its capacity by getting an extra 4 modules added. At that time we discovered the need to match the modules charge levels during installation of the extra modules. I have the disadvantage of heavy winter shading and cannot fill the battery purely from solar during winter so top it up with cheap grid imports from Amber in the middle of the day (currently charging at 2c/kWh) to cover our peak usage and send any excess back if the export price looks good. There is Amber for batteries but I use some Home Assistant controls to trigger the battery to charge/discharge when I want.

    • Finn Peacock says

      Good to hear, Paul.

    • Thanks Paul.
      Have read before about Home Assistant controlling solar/battery installations, and looked into it. But couldn’t figure out how to set up or apply it.
      Do you have any literature, links, explaining this?

      • Hi Neil, I started out using Sungather from to collect inverter data and display it in Home Assistant but later moved to using modbus directly e.g. as that meant I could make the inverter charge, discharge, or turn off the battery as required. I have some further HA customizations and automations to schedule charge/discharge when the Sungrow battery is at an appropriate level and the Amber price is favourable, turn off the house battery when charging the EV, and export limit the inverter when the Amber FiT goes negative (and undo it when it returns positive).

    • Shane Dufty says

      Hi Paul, would you be able to provide me with any details or links regarding the home assistant control. Similar situation as you but my current method is labourious and manual. Looking a home sssistant to automate the processes when I can get around to it. Thanks.

    • I noticed the comment that Paul made about the need to equalise the charge level. How long might this procedure take on a 3 module bank? What might happen if a module is added, as a replacement for a faulty module, and the charge levels are not equalised? Would the system only recognise the new module? We are having issues with a new instal unfortunately.

      • Hi Jo, In my case the difference between the old and new charge levels were large. The old ones were >80% and the new ones <20%. I thought the BMS would balance them itself but odd things happened instead. As the level dropped from 100%, at around 80% or so it suddenly dropped to 0% then as it charged up from 0% it suddenly jumped back up to 80% so I was only getting a fraction of the real capacity available for use. From a simplistic view I assumed this was because once the new battery modules discharged to 0 the whole stack was considered empty (even though the old modules still had lots of charge) and when the old modules charged up to 100% the whole stack was considered full (even though the new modules had hardly any charge). Then I found this Sungrow document: It detailed the need to force discharge the old modules down to the shipped level of the new modules (15-20%) before installing the new modules (essentially manual balancing them). I don't know whether an automatic balancing would have eventually happened in my system or not (a good question for Sungrow). I seem to remember it took about an hour to force discharge the old stack. My installer (Solenergy) was very patient and helpful with this and once we manually balanced the old and new modules it has been running as expected since.

        • Hi Paul
          Thanks SO much for your reply. It sounds like it’s exactly what’s going on with our system. I sent an email to the installer to say it appeared as if only the single new module was being recognised. They were having no luck getting a response from Sungrow but didn’t relay this to us. I’ve sent them the info and link you provided so hopefully we’ll get it sorted next week. The support from Sungrow has been disappointing for the installer and us. If Sungrow had sent a ‘caution – special procedure required’ note and link with the replacement battery, it would have saved a lot grief. Might be a good one for the suggestion box. Thanks again ?

        • Hi Paul
          The installer came back Monday and did a procedure to balance the batteries. This wasn’t done when he replaced the faulty module on August 1.

          We would have expected to see 9.6kWh (3 modules) connected, force a full charge and then force discharge about 7kWh to get the 9.6kWh pack down to around 20% soc. Then reconnect the 4th mudule and charge the whole pack about 10kwh to be fully charged. Does that sound right?

          It’s hard to tell, as we’re not sure that we can trust the graph data now, but it appears that there was only a 2kWh discharge during the procedure and then a 4kWh charge. It was very heavy weather and the end of the day so don’t know if it might’ve charged more or not.

          Yesterday the system seemed to be charging normally until about 10am, then it suddenly jumped from 34% to 100%. No one was home until later evening and it was at 0% after 11pm, at which time it drew 6KW from the grid for 20 minutes. As a comparison, while we were waiting for the replacement module, the 3 modules pack lasted all night and took about 4 hours, to 11:30am to fully charge. We haven’t seen anything like that charge/discharge profile since. It is only charging and discharging about 4kWh.

          We let the installer know yesterday but they came back with:

          “…Technician asked is this a new battery and said that would be the reason.

          The technician checked off a list and said the following:

          The battery is online
          The battery is communicating
          The batteries are 100% charged
          He checked that all of the firmware updates had been done.
          There are no faults logged
          There is no active fault
          The backup mode was not enabled, but he did that online whilst he was talking to me.

          He said to just keep a check on it, but all should be fine…”

          It seems they didn’t look at the system graphs showing the charge/discharge info. We know it’s not fine and are concerned that all of this may affect the overall battery health and life of the system. Any input much appreciated.

          • I don’t have this unit, yet, but will in a month or two.
            I was told by one installer that he gives the password that allows access to the configuration settings etc to customers he likes. I immediately offered him a beer jn response!
            Seems to me to be a pain in the #### to have to rely on the installer and Sungrow to do the deep digging for fault finding.
            Obviously one needs to be careful messing about with settings but screen shots of the set up can over come that if you’re bold, or silly enough, to mess with those.
            Anyway, I have commitment from other installers to be provided same. Whether the one I have signed will or not ..will see.

          • Hi Jo,

            One of the issues you may have with them not following the procedure the first time the new module was installed, is that you probably cannot tell what that modules SoC is now as it will have been somewhat charged/discharged since. In my case I was adding 4 new to 4 existing modules. The installer and I over a couple of days were able to fully discharge/charge the old stack of 4 then the new stack and finally combine them into a stack of 8. I don’t know how you would do that with a 1+3 module split as I think the minimum stack size is 3. I would contact Sungrow tech support and ask what they would suggest when the upgrade procedure is not followed from the start. I would hope that the Sungrow BMS would eventually balance them out automatically (as happens with EVs) but I have not read anywhere it does. It would be good to get a yes/no from Sungrow as to whether the BMS does do that, whether it can handle very large differences in the modules, and how long it might take.

            If it were me, for something to show the installer and Sungrow, I would do a forced discharge to empty, measure the amount of energy discharged, then a forced charge to full and measure the energy used. See if you are getting within 5-10% of the full capacity. If its significantly less and you see huge jumps (like 34%-100%) I imagine they are still unbalanced. I was seeing jumps in the order of magnitude of 0 to 72% – I still see some small jumps like 5% to 0% and 95% to 100% but I can live with those. I saw no faults reported in iSolarCloud other than expected communications ones when the installer was replacing battery modules.

            Of course I am just an owner that has had this experience too. I am not an installer nor an electrician. The best people to talk to would be Sungrow themselves. I hope you are able to get it resolved promptly. In my case I had a very proactive and helpful installer who was keen to get it resolved quickly.


          • > Yesterday the system seemed to be charging normally until
            > about 10am, then it suddenly jumped from 34% to 100%.

            These jumps are a sign of unbalanced cells. I’d try the following. Take out the new bank. I assume your original three are somewhat balanced. Discharge them tto very low, needs to be below the new bank. Add the new module and charge to full. It will be the new module which stops the charge once the first cell in that module reahces 3.65v. Remove it and charge the original three to full. Add the new module and you should be much closer to expected capacity.

            Starting with 5 modules, you can manually balance the tower:
            1. discharge to 95% and charge, remove the module that stopped the charge
            2. Repeat until 2 modules are left, remove the 2 and add the all the ones you previously removed.
            3. Discharge to 85%
            4. add one of the remaining 2 and charge to full, remove it as it should be the one stopping the charge
            5. Repeat step four with the other of the two modules
            6. With the last two modules removed again, charge until full
            7. add the remaining two modules

            You should now have a much more balanced tower. This works as one after the other all modules will be charged until the fullest cell in the module reaches 3.65v stopping the charge. There are still going to be differences between the 20 cells within each module which the sungrow circuits are not able to balance perfectly but you’ll be much closer to full capacity than before.

          • Since last commented here had a 9.6kwh sungrow battery installed with 10kw hybrid sungrow inverter. A fee months later, added another 9.6kwh set of battery modules.
            I have made a number of measurements of the consumed and charged power when partially charged, fully charged and totally discharged.

            Taking the amount of SoC% depletion after midnight to its lowest point the following morning, when I divide the Kwhs consumed by the %the soc% reduced [each recorded in th4 ap] I get anywhere between 12 and 16 Kwhs.
            Have done this measurement numerous times with this result.
            If I force charged to 100% SoC at midnight, and run HWS and EV charger until battery depleted to 0% at about 6am, the amount consumed is about 16kwhs, not 19.2Kwhs.
            Similarly, it takes only 18Kwhs to recharge from 0% to 100% SoC. This is close to acceptable as is only 5% difference which might be the reserve charge retained to allow thr BMS to commence charge.
            Have done these tests twice. The first time a surge of 9kwhs was recorded from grid just as the pv power started to recharge, not so the 2nd time.
            Sungrow and thr installer reckon this is all ok as is due to modules still equalising.
            The 16kwhs of consumable power is particularly concerning being 16% below specified capacity.

          • Hi Neil,

            In addition to estimating the energy from the SoC% and battery size, you can get the battery energy numbers out of iSolarCloud. This is what I have been doing to monitor my battery stacks (I also have the numbers in Home Assistant too). If you log into iSolarCloud and use the Curve tool you can select the measures “Battery Level (SOC) %” , “Total Battery Charging Energy (kWh)”, and “Total Battery Discharging Energy (kWh)”. I then select a date range that includes 100% and 0% (or as low a % as it will go), 5m stats, switch to table view and read off the kWh numbers for 100% and 0%. Do the deductions (since total is cumulative) to get energy in during that period “Total Battery Charging Energy” and energy out “Total Battery Discharging Energy” deduct those and get energy stored or consumed for the full charge or discharge. Since my last comment I have added a second stack of batteries and am getting much less than expected from the combined stacks. As well as the best/worst module within a stack driving the high/low of the charge, I am finding that one stack is getting consumed faster than the other and the discharge stops when that stacks hits 5%, when the other stack can still have an unusable 30% left. It’s frustrating how long its taking to get resolved. I expected the battery management system to be much smarter and to be able to managed this for itself and not have to do manual intervention.

            Best of luck

  2. I was almost going ahead with the Alpha 10.1 kw battery for $10K installed. but re – reviewing your take on these got cold feet (which had alot to do with my slender wallet also.)
    If I was to go with sungrow I think I would keep my 6 yr old fronius primo inverter as it just looks so cool on my garage wall! And I’ll call my original installers (Solar Quotes originally pointed me to, thankyou) and see what they could do me for.
    Good article and may become very revelant for me.

  3. Hi Finn,

    What is the limited backup for the Sungrow inverters and what would the maximum be? Also, how does the back up work – for example when the grid is down but the sun is shining during the day – would the whole house be able to be powered by the solar (if sufficient power) and the batteries supplement the rest or will power only be for the backup circuits?

    • Finn Peacock says

      The SH5.0RS backup circuits are rated to 5kW and (8.4kVA for 10 seconds). But if you are going to load it up to 5kW, you need to be careful what kind of loads are connected.

      As Anthony explains here:

      “Hybrid backup circuits are limited to the throughput rating of the inverter, regardless of if there is grid power available or not. The inverter doesn’t have a higher “pass-through” rating when grid-connected, so the inverter effectively throttles whatever is on the emergency circuit.

      It’s not a problem for the average single fridge and lights scenario, but this limited capacity means the backup circuit can struggle with high inrush loads such as induction motors. The motor in an extra fridge, freezer, air conditioner or household water pressure pumps will draw up to seven times their running current when starting.”


      When connected to the grid, the whole house is powered by the solar and batteries for up to 5kW of power, any more than that and the grid has to top up. If it was AC coupled, the battery could provide 5kW and the solar another 5kW – up to 10kW of power. So – that is a disadvantage of this DC coupling design.

    • Finn Peacock says

      Maximum backup capacity is 5kW (8.4kVA for 10 seconds) – the hybrid design means you have to be mindful of inrush curren.

      When connected to the grid, the whole house is powered by the solar and batteries – solar first – for up to 5kW of power, any more than that, and the grid has to top up.

  4. George Kaplan says

    If you’re paying 46c/kWh that certainly makes grid power more expensive and batteries less painful. But in states where coal power is still cheap … : – P

    How much more complicated is it to mix and match solar inverters with batteries\battery inverters?

    You note that the 12.8 kWh battery system covers a third of the flat for blackouts, but don’t specify if there’s a changeover flicker\blackout. Will you keep power when the grid drops out, or only get power ‘back’ after a delay? Certain electrical devices are sensitive and don’t like brownouts or blackouts so a constant flow of power is better for their life expectancy. Is this installation an alternative to getting UPSes (Uninterruptible Power Systems) or are they still required?

    Is that a gas stove I see? : – P

    You say a 12.8 kWh battery is too limited for a whole house, but is that actually true? Of the 18 days of data I have for this month (no blackouts and corrupted data – yay) that would have covered my total power usage half the time, and my grid consumption all the time – I relied on solar more than grid power half the time. But I don’t have a 6.6 kW solar system. Wouldn’t it thus be more accurate to argue that the battery is a decent size – assuming you’re not a family that uses 13 kWh+ per night, but that the solar system generating the power is too small? (To be fair my power company claims a 2 person household in my area averages ~14 kWh, but a large solar system, and perhaps lifestyle choices, can radically reduce that figure!)

  5. Bernie L says

    Hi Finn,

    Thanks for the article, it’s interesting to see what goes into a real life Sungrow battery installation.
    Just a few of questions. 1: Do batteries have to be level to be installed? 2: Does the battery you had installed need a post to protect it as it’s in an area accessible by vehicles. What is the minimum distance away to get away from having a post installed? 3: Can the battery be installed that close to an A/C unit if the refrigerant used in the A/C is a flammable gas? What is the minimum distance away from a gas appliance does it have to be?

    • Finn Peacock says

      1. Ask the manufacturer for your battery model; it may include a cooling circuit that needs to be level. As for this Sungrow battery, I could not find anything in the install manual that required it. But it has threaded feet, do the guys made it bang on with a spirit level anyway.

      2.No – there’s a concrete wheel stop before the battery so you would have to try very hard to drive into it.

      3.AS 5139 says it must be 600mm horizontally and 900mm vertically from such appliances. Gas cylinder minimum clearances are bigger – as per AS3000.

  6. John Corney says

    Hi Finn, apparently there is a 10kW Inverter (SH8.ORS & SH10.ORS) on the way. September I Believe.
    The SH10.ORS is approved at 9999W to avoid Ergons crazy rule.
    The CEC already has already approved them.
    The datasheet and user manual are available on the Sungrow Australia website. The manual is primarily old info from the smaller inverters, hopefully, they will update it before the release date.
    I am going to upgrade to the 10kW unit from my existing 6kW Hybrid.
    I have an 8.1kw array and have space to double that.
    The 10kw inverter apparently can handle up to a 20kw Array with a battery connected.
    Isc is 20A for each input with 4 inputs.
    I have delayed adding batteries until I get the bigger inverter.
    The way I see it is that you would have to have 2 batteries in parallel to achieve the 10kW backup power.
    It appears both the 8kW and the 10Kw inverter can supply 10kW in backup mode.

    • Have confirmed with Sungrow that new 9.999Kw Hybrid single phase inverter will be released in August.
      Data sheet and manual here

    • Tom Sjolund says

      Thanks John & Neil,
      I only found out about Sungrow 10 from my electrician/installer last week.
      We have a duplex house, our unit has a sungrow 5 and 6.6 of panels and 4kWhr BYD battery. The other unit which we have as an AirBnB has a Sungrow 2.5 and 2.5 of solar.

      I’m upgrading both systems, ours to Sungrow 10 as many panels that I’m allowed and 16kWhr BYD battery, the AirBnb will use our existing Sungrow 5 with at least 6.6 of panels and 16kWhr of battery and will the go off-grid.

      We’ll stay on grid and just export. We’ll have a changeover switch for the batteries, just in case.

  7. I have two Sungrow SH10RT Hybrid Inverters, one battery to each, master/slave config and two SBR192 batteries, 19.2kWh in six 3.2kWh modules each stack. These are connected to 24.9kW of panels (60 415W Jinko). I monitor the system using the iSolarcloud web and app.

    The Solar part of the equation works well and so does the power fail backup. I have most of my house configured with the exception of my 3-phase ducted AC, main oven and cooktop. In power fail testing it has all worked as expected with very fast cut-over to battery as advertised and configured in the system at 20ms, I like that part very much.

    As for the batteries, I have problem with the stated capacity vs actual plus I have one battery set that simply appears broken since installation and am having difficulty in getting it fixed, work in progress.

    The batteries stated output minus the standard programmed safety margin of 5% on 19.2kWh, is 18.2kWh, my average full discharge output in the working set is 17.1kWh over the last two months. The faulty set it 12.6kWh or 65% of advertised capacity and consistently drops below the level where is triggers emergency charging from the grid, broken.

    My conclusion while still trying to get the broken one fixed, don’t believe the advertising on the expected output – Sungrow actually claim 100% usable on the 19.2kWh, on my “good” battery I average 89% and even if you did get the maximum it would be below the emergency recharge level of the battery management system and would by default trigger an emergency recharge from the grid back to what is the default 10% level, I know, I see it nearly every day with my broken battery (2kWh from the grid).

    I can rationalise the battery capacity as just badly written advertising, but it must be kept in mind for any economics or “how long will it last on backup” type calculations. Now if I could just get Sungrow to fix my broken battery. Assuming they do get it fixed I want to add some more modules.

    • > I can rationalise the battery capacity as just badly written advertising

      It’s not. I’m fairly certain the banks in your tower are not balanced. The sungrow BMS/Charging circuit is horribly bad at balancing large deltas. I have described a procedure to manually get the banks close to one another in a post still awaiting moderation above. Give this procedure a shot. I would bet that you will increase your usable capacity quite substantially.

      When extending my existing tower with four banks to 8, I followed the sungrow documentation. Despite doing that, my capacity only went up by a kWh or so. I then charged both sets of four to full and combined them which was better. I went from around 12kWh to a bit below 20. Still not ideal. I then executed the procedure described in the other comment and it went up to 22. Still 3 missing from the advertised capacity but I’m also still seing deltas so I’ll do it again. You should be able to get very close to the advertised capacity. My initial set of 4 banks was aparently really welll balanced. The 8 bank tower is getting there.

  8. If the retrofit cost $14k, then you need to include the cost of funds, I.e. what the $14k would have saved you if it was spent paying down the mortgage. At 6% that’s $860 a year. Given your best case savings are $1825 and as you’ve already outlined, you’ll get nowhere near that figure, the “payback” date is well past 14 years at which point the battery will be long since our of warranty.

    • Finn Peacock says

      I’m using simple, not discounted payback to keep it simple.

    • George Kaplan says

      Doesn’t that presume Finn has a mortgage on the place? Though to be fair interest rates for savings are at least 5%. On the other hand you’d need to factor in inflation, 20%+ on some things, and forecast electricity prices rises 20%+++ this last year, so the simple method causes less headaches.

      • No, capital has opportunity costs regardless of whether you have a mortgage. Bank shares yield 8% franked, etc. I keep hearing renewables are going to make electricity cheaper so predicating your purchase on 20%+ increases isn’t sensible, nor is the war premium on gas/coal prices. Additionally I also keep hearing that battery prices will fall, so perhaps this isn’t the time to buy a something that is at best marginal with the very unrealistic daily complete exhaustion of the battery to achieve the savings.

  9. Noel Guillaume says

    May sound silly Q..Is it possible to have another solar package + sungrow batt to enhance my powerwall battery. ???

    As you an option to getting another powerwall batt ???

    • Finn Peacock says

      It’s possible – but would be messy. Second Powerwalls are thousands cheaper than the first because you reuse the gateway and the installation is usually much simpler.

      Unless you bought your Powerwall before all the price rises…

  10. Steven Fennell says

    Nice article.

    Have you done any reviews on solar racks for those that don’t have the roof space or prefer to have the solar off the roof,. Or a link to someone doing that in the greater Brisbane area?

    Solar racks /tracking are not exactly the same as solar reviews that you do but I am in a situation where I don’t have the roof size and unless I move may have to use this option

  11. Hi Finn, This is great research. i feel i understand my options far better. 1 question, what do you think of the cyber risk associated with the chinese inverters

  12. Hi all

    I thought we would give you an update on our Sungrow battery saga…

    Since 9 August the installer has been back twice to run through Sungrow recommended procedures. However, there is now no way to tell the soc of the fourth module. Now we get to about 70% charge, then the system immediately jumps up to 100%, or to about 35% discharge then the system immediately drops to 0%. Shortly after it indicates 0% it force charges from the grid. We get about 7kWh charges and discharges each day (for a 12.8kWh system) as opposed to 4kWh before 9 August.

    Over the past six weeks we have learned a couple of interesting things that others might want to be aware of:

    1. It appears that the three ‘good’ modules are all more than one year old (the manufacturing dates of two read June 2022, and other, April 2022). The warranty expressly states that the battery system is covered for 10 years or no more than 10 years six months from the date of manufacture. Check your module serial numbers for the manufacture date before installation.

    2. The other is a potential warranty issue for us and relates to the original replacement of the faulty battery. It states that if the battery augmentation procedure (as noted by Paul in the comments above) is not followed correctly, that the warranty will not cover any problems deemed to be arising from this procedure. It is a very broad statement and could encompass almost any future problem that arises.

    The battery augmentation procedure is not in the printed installation manual that came with the system. It is in the user manual, which we could only find online. When the replacement battery module arrived it was simply placed on the other 3 modules.

    We have now requested 4 replacement modules, and still believe that Sungrow is a decent brand, but their customer support is lacking for both us and the installer. We really like the app – we can track everything easily and could prove the system was not working optimally.

  13. I have almost the same situation. My system is two battery sets 19.2kWh, two SH10RT inverters battery connected to each in Master/Slave config.

    The installer was clueless with the installation from the start and wiring the inverters as not master slave with an energy meter each – NOT per Sungrow instructions. I questioned this and was told by their “expert” – normal. The batteries did not work other than simply charging, ie no discharging at all. Next visit to fix some faulty and potentially dangerous wiring I showed the installer the instructions and insisted he revisit his installation, he followed the manual and hey presto, it worked, mostly.

    My initial install was 2x16kWh batteries. Shortly after installation I decided to add another 3.2kWh module to each stack. The installer was told by his “expert” to just add them. I challenged this got him to almost follow the manual, not quite to the letter of the instructions but close. I think this is why the first set a closer to rated but still not right, well below rated output. For the other set impatience set in and the batteries were eyeballed via the discharge on the battery bar graph, close enough, lets go. I should have stepped in; this was a serious mistake and likely the cause of the 30%/70% issue.

    The first average 16.9kWh discharge not 18.2 (19.2 minus safety margin) seems faulty.

    The other set behavior is almost exactly like yours just different values. During discharge at 33% battery drops to 0, emergency recharges to 10 (the min recharge value), on charging 70% and jumps to 100%.

    For two months my installer tells me they are trying to get Sungrow to look at it. I have provided ample proof of the issue including citing posts on this forum. My installer seems incompetent.

    At this point I may be seeking replacement batteries as they are not fit for purpose, are not matching anything like the advertised energy storage, and appear faulty. The evidence to me points to a faulty install.

    • Hi Kevin

      Well, after almost 2 months (and a fairly strongly worded email mentioning ‘not fit for purpose’ according to Australian Consumer law), today we had our 4 modules (12.8kWh) replaced. We added 2 extra modules as we had always intended to have 6, but decided we didn’t want to risk issues in the future with an incorrect augmentation procedure.

      One thing that was done completely differently, was that the supplier requested directly from Sungrow that the replacement batteries be delivered fully charged. This is not in Sungrow’s protocols and we replied that we did not request this.

      We also asked the installer to let us take photos of the serial numbers on each module to make sure that they were all well within the warranty requirements, and were from the same manufacturing batch (the last 4 had more than 16 month’s variation). We also asked that the installer check the voltage of each module. We saw him check 4 out of 6, but could not see the voltmeter. However the numbers he read out were very similar and we can only assume he checked the other 2 and that they were similar.

      All seemed well until the SOC reached 75% this evening. It dropped immediately to 0 and started to recharge from the grid, until it reached 5%, using about 3kWh of grid power. It seems we are back where we started. We are wondering if it could be something to do with the BMS (the first one had to be replaced back in early July) or the inverter. It seems so unlikely that we would be unlucky enough to get another 1 (or even 2) faulty batteries again. It’s incredibly frustrating and very stressful, to think we have to start battling to get this sorted again.

  14. Steven Fennell says

    My reluctance to update my solar array and add a battery are not from, well not entirely from a financial perspective.

    I have not entertained the thought of a battery pack yet simply because of all the comments above and below.

    Charge and empty at this rate , charge, reboot, configure when it becomes idiot proof then I will get me a new solar system with a battery or batteries.

    Computers are plug and play why not solar systems?

  15. Hi, I am looking at getting the Sungrow battery bank.
    Has there been any further news on the quality of the system

  16. Ramzi Welhi says

    Hi Finn,

    I’m pretty new to the solar industry, and wanted to know your thoughts:

    I’m about to build a house where my builder provides 6.24Kw of solar (390 watt JA panels) as standard, with a 5kw inverter. I have the option to:

    1) upgrade to 9.75kw with enphase iq7A fr $8,710
    2) upgrade to 9.75kw with 8kw inverter (module not provided)
    3) upgrade the string invert to a hybrid inverter for $1,568

    My house that I’m building faces just off north (north-east), with the main roof real estate located on the east and west side of the roof (Rectangular 38 square double story house).

    My concerns that I would have 3 sides of the roof filled up with panels and thus may cause the panels to underperform since string inverters only operate at the lowest producing panel?

    The intent is also get a battery (10+ Kw) but I hear a mixture of pros and cons for getting micro inverters vs string. Now I am looking at the Tesla wall 2 or Sungrow batteries since they offer reasonable bang for buck.

    My question is what would you had the options above with the intent to get a battery in the very near future, with some minor back up systems in the event of a black out (e.g. fridge, lights, internet and tv) and the ability to expand in the future (2 power walls or additional modules for the sun grow)

    I will also ask how much the upgrade to the IQ8HC and to 410w panels but this is not currently offered by the builder at this point.

    Thank you for your time.

    Kind regards,

    • Finn Peacock says

      A string inverter will work fine on 3 roof faces if properly designed. You’ll either use a string inverter with 3 separate MPPTs or one with 2 MPPTs with the East and West sharing (counterintuitively works fine with a good, modern inverter).

      You don’t need microinverters.

      Expect to pay under $3,000 to upgrade to 9.75kW – but get more if it will fit – 10kW inverter and 13kW of panels is a nice size.

      Your call if you want Sungrow or PW2 – both great choices. If you want Sungrow, get the hybrid inverter and Sungrow power meter installed. Ensure they run a wire for the backup circuits at the same time. Only do this if the same installation company will also add the battery down the track – or you are asking for trouble.

      If you can’t get the same company to install the battery – go for the Powerwall – it’s the easiest retrofit.

      • Have just installed a 10kw [9.999kw actually, which may end up being important] Sungrow hybrid, 13kw of pv modules and 9.6Kwh of sungrow battery 3×3.2kwh battery modules.
        We use, direct from pv modules and from battery about 30+ kwh a day. Pool pump accounts for nearly 12 and hws 4. I have been running aircon for free because I can see that the system has maxed out the 5kw export cap yet is producing only 7-8kws, so know that another 1500-2000kws usage will still result in 5kw export. So that pushes up daily usage.
        Production averages about 60 kw on good days, again depending on what I can consume as system will not peoduce more than can be used or exported; max so far is 67 kws.
        Battery is usually fully charged by 9am most days if not stormy overcast, about 10am on overcast days. This from about 20% depth of discharge overnight.
        The whole house is on backup circuit as the inverter will deliver 10kw, or over 40amps, of backup power. Also had a simple time for HWS installed and would not run HWS, pool pump [on smart timer] and multiple reverse cycle aircons heating the house all at once as, say, turning on electric kettle would prob exceed that.
        Point of all that, is to say am very happy with the Sungrow kit. The availability of 10kw inverter with10kw of backup was a game changer. The Isolarcloud ap used by Sungrow is basic and gives very limited control. But sungrow do give out the “Admin” access password so one can make some [careful] adjustments to battery operation/usage without requesting retailer, installer or Sungrow to do it. It has 4 x MPPTs by the way.
        If you are in QLD, wait till its $3-4000 battery subsidy is implemented early 2024 before buying the battery. This has been annohnced by gov. Sungrow 3.2kwh modules are about $2,000 each. The minimum is 3 modules. I will double battery size when it does.

        • Tom Sjolund says

          Hi Neil, I just upgraded from a Sungrow 5kW (6.6kW panels) with 4 kWhr BYD battery to a Sungrow 9.99kW inverter and the Sungrow 9.6kWhr battery on our Unit.
          We have a Duplex, the other Unit had just a 2.5 kW system, I used our old system for it and added 12 kWhr BYD batteries.
          I’m getting simiar power out put as you.
          Very happy with it all.

    • Seems odd to me that you would be restricted to what’s on offer from a builder, as opposed to a solar installation retailer that is accredited to design and install the system. I would want to discuss and contract the purchase directly with the solar retailer/installer. If you have warranty issues down the track will you be relying on the builder still being in business? Do you have a say in the choice of installer and can satisfy yourself that they will likely still be around in 10 years and their quality of install history is acceptable?

  17. What battery/Inverter Combo would you recommend to backup a whole house. I am looking to add a 2nd system to provide more power to an existing 5kw Sungrow inverter with 6.6 panels.

  18. Adrian Oakey says

    Hi Finn, wondering if you are seeing some of the same operational characteristics that I am. My parents installed a SUNGROW. SH6RS (I am Qcells myself so my obersavations are relative to how that system works). So far the overall performance has been fine, but…there is always a but. Given that you now have 10 months operational experience, could reflect on whether what I am observing is typical to what you are obeserving.

    1. Negative load (calculated – not real). I surmise thats its a result of a delay between the remote energy meter and the measurements of power within the inverter. So when there is a noticiable change, typically in solar output dropping, it results in calculated negative load. Could be a fault in either meter, comms or calculation – or is this normal? Meter is right next to inverter.

    2. Cutin of the battery. It seems to require around 150W of load greater than PV output before the battery cuts in. So when solar drops off at the end of the day, there is a small period of import. Or in the case of my parents who have a base load less than 150W, continues to import after PV generation is zero, until a high load is turned on. Deliberate design – if so any idea why? or a fault? Battery SOC usually 100%.

    3. When charging, goes to 100%, drops off through day about 1 % then has a small topup at end of day. Normal behavour?

    Any insights (from any hybrid sungrow users) appreciated. Has been discussed with installer, but before escalating would like to understand whether this is typical behaviour (its not with Qcells).


  19. Similarly, I was seeing random 100w amounts taken from grid. This seems to have stopped and now regularly see much larger amounts, over a Kw Sometimes, despite battery being well charged and pv generating more than load. Whether they actually add up to any paid for grid use, am not sure.

    And also, occasionally see the 1% drop in battery soc even though no battery usage.
    Sungrow are hopeless at responding to these types of inquiries…worse actually, they dont reply at all.

  20. Hi, I have a slight variation that does make things a little different but maybe similar enough to be relevant. My setup is two SH10RT Hybrid inverters in what is called master/slave where one of them (the master) controls the operation of both of them for many functions. I have two SBR192 battery stacks, one on each inverter. The whole system works remarkably well during discharging with the system swapping battery sets during discharge back and forth between the batteries dischargine one set at a time to maintain synchronised battery levels. (in a blackout each inverter/battery operates seperately for its own own backup circuit) Re your questions:

    #1 yes, as I see it just measurement timings causing these readings. I use both the Sungrow iSolarcoud and also Home Assistant via ModBus communication to monitor my system(s) and can see all this going on.

    #2 the cut-in is a setable value. According the version of the manual I have is says “The hybrid system will start to discharge the battery when the import power value exceeds a threshold of 70W”. Perhaps you could check your inverter settings for this.

    #3. Mine jump to 98 or 99% then the charging rate drops right off and slowly creeps up to 100% over another half an hour or so although this does vary depending on the over all charging rate. Fast charge days with full sun do this stop at ~99% regularly, slow charge days with clouds often just go direct 100%. I suspect battery temp regulation and chemistry being the reason.

    I hope this helps,


  21. Tom Sjolund says

    In November 2023, I installed the Sungrow 10kw Hybrid Inverter SH10RS (actually 9.9kw) with Sungrow high voltage batteries x3 modules (9.6kWhr). I love the system, most times I only use 0.1kWhr/day on the odd occasion 0.0kWhr.

  22. Thanks Paul. [Sorry can’t seem to reply directly to your last post]
    Yes, am taking my data from “The Curve” data. And the “Summary” data. The Curve allows calculation of the SoC depletion after midnight and Summary shows amount of kwhs used iver same period from battery. Later÷former=100% of capacity and should be close to 19.2kwh.
    Sungrows response is gobbledigook and circular and I will get back to them about that.

    Sungrow response to me, via retailer is below. It includes a summary comment by retailer at end re “equalise soon”.

    “As discussed, please see the below response from Sungrow regarding the capacity of the battery. 

    “R&D replied the battery capacity is not bad. There seems around 4% difference for the capacity mainly because the 5% swing between the modules but it will self balance soon.”

    “The calculation capacity can be calculated like this, 1401.9-1384.8=17.1/total battery capacity 19.2*100%=90%+remaining power 5%=95%, then the SOC difference between modules is about 5%, and the capacity is exactly 100%”

    The 5% variation will equalise soon. This normally happens when batteries are fully discharged and charged. In your case, the batteries are not fully discharging. The way you could force this is to turn off the PV switch on the Left hand side of the inverter once the batteries reach 100% SOC. This will cause the batteries to cover the consumption and discharge fully. Hope this helps. 

  23. What battery and inverter system would you go with if you wanted to back up the whole house even if it lasted only 3-4 hours to run a central AC etc into the night before it drained it?

    • Anthony Bennett says

      Hi Vaughn,

      It’s a length of string really. Need to know how much energy you’re using.

      My choice is this :

      However Fronius, Sungrow or GoodWe are also great IMO

      • Great very much appreciated with the reply.

        My main concern was the throughput? Or was it output? Since the central air needs around 5kw or so to “ramp up” on startup I was advised a lot wouldn’t be up to the task and would trip.

        So I was kind of lost there as I’m not an expert in the field.

        Recently I was put onto SigEnergy, however they aren’t yet approved (and who knows when they will be with what’s going on over at CEC now and the transition etc)

        • Anthony Bennett says

          Hi Vaughn,

          Single or three phase will make a difference. As will the type of load. If it’s a modern “inverter” type air conditioner with variable speed drive then they are inherently easier. If it’s a traditional induction motor then it’ll need six to eight times the running current for startup. That kind of inrush is easy for something like a Selectronic SpPro with 240% surge rating but harder for a lightweight hybrid with only 120%

          • Sorry as soon as I wrote it I knew I should have stated I have three phase.

            Now you are asking the hard questions, it is a recent build mid 2020 Daikin central air/heating so hopefully the first? But to be honest I’m not sure (unless all modern ones are inverter (hope so)

            Knowing I now have a three-phase (plus I’m trying to add to my existing system instead of replacing just due to budget it seems) does it change your recommendation?

            Currently I have a 6.6 kWh system, solar is facing holy East, (Not my choice when I got it installed unfortunately those years ago) however, I’m looking at adding another line on the East, some on the North and the rest on the west….. Which complicates things as well apparently due to lack of MTTPs? (Such as with the 10kWh Sungrow only having two)

            This is all with a GroWatt three inverter. So mostly I’ve been quoted hybrid inverters for the new system, to keep things separate.

            I like your recommendation and I might get some quotes on the .Selectronic SpPro So thank you )

            But knowing the information you do now, would there be any backup recommendations?

          • Anthony Bennett says

            Hi Vaughn,

            3 x SpPros for 3 phase is going to be expensive, and won’t play well with a GroWatt, neither do I so i don’t blame them.

            Fronius Gen24 Symo 10kW is an option. If you have equal sized arrays on the east and north connected in parallel to one mppt, the other mppt can have the west array.

            15kW Sungrow are now available but the 3 x mppt aren’t able to handle parallel strings.

            Either way you need to consider phase balance too, and what your network will allow. Maybe bin the GroWatt?

            Time to get a quote from a designer.


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