The battery did not perform as expected during the 2018/19 summer temperature tests, with the battery cycling at a reduced charge and discharge rate. The manufacturer stated this was abnormal and took the test battery away for their own analysis in March 2019. The battery was not replaced and testing for this battery has concluded.

ITP had difficulties in commissioning this battery (i.e. setting it up and getting it running with a connected inverter). The battery pack had issues with reliability and shut itself down frequently. The Chinese manufacturer Sinlion would not honour the product warranty for this fault, which apparently occurred with other samples as well, and ultimately Ampetus, the Australian company selling the batteries, went into receivership. 

This interesting battery is not lithium-ion or lead-acid – instead it uses a salt water electrolyte. Unfortunately, ITP wasn't able to get this battery fully set up and running with an inverter, as Aquion went bankrupt in early 2017 and could not provide the final support needed. The company has since been bought out but is not supporting products purchased before the bankruptcy, and it's not clear what presence they now have in Australia.

This battery generally ran without problems, and demonstrated high efficiency, though its capacity fade appeared to be accelerate over time. Eventually the battery failed in 2020, with the fault suspected to be an internal battery management system (BMS) failure of one module. The battery was replaced in the test in late 2020 with a newer version (LVS), which so far is running without any problems.

This replaced an earlier BYD B-Box HV battery which was installed at the start of Phase 3 and ran without problems, but was superseded by the newer HVM model, and ITP thought it better to test the new model instead. The HVM had some early problems in 2020 with getting "stuck" after a scheduled outage (it couldn't be turned on or off) and later with its internal DC breaker tripping. BYD assisted in resolving these problems – the second problem was due to out of date firmware in the Sunny Boy inverter being used with this battery. Since then it has run without problems. It's too soon to draw any particular conclusions about this battery.

The CALB is the only battery system in the trial with an external BMS from a different manufacturer to the battery itself. A faulty cell was replaced early on, and since then there have also been issues with cycling, possibly due to another weak cell or poor management by the BMS. Although test data indicates that this battery appears to perform efficiently and was reasonably likely to meet its lifetime claims, the operational issues reduce the reliability of this data. Testing for this battery has concluded.

This Deep Cycle Systems battery was installed in 2020 as part of Phase 3. Its BMS isn't designed to communicate with the inverter, so the inverter has to estimate the state of charge at any given moment. The battery is cycled between its minimum and maximum voltage limits as per DCS advice but the full capacity of the battery is not discharged through this method. Nevertheless, the battery is performing without problems. It's too soon to draw any particular conclusions about this battery.

This advanced lead-acid battery has had a number of operational problems relating to integration of the battery with the inverter, some of which may have been exacerbated by the accelerated cycling program. EcoUlt replaced the original batteries. Since then, EcoUlt advised ITP that the replacement product currently on test had been permanently damaged. No conclusions can be made from the data collected. ITP says that this is a demonstration of how essential it is to get the battery/inverter integration just right, rather than a problem with the EcoUlt battery itself. Testing for this battery has concluded.

At the time this battery was purchased for Phase 3 of the test, it was sold by ABB, but since then ABB's solar inverter business was acquired by FIMER, which is honouring existing warranties. The battery is performing without any problems so far. It's too soon to draw any particular conclusions about this battery.

This Phase 3 battery's sodium nickel chloride technology is promoted as having high density, a wide operational temperature range, and low fire risk. In addition, the battery is 100% recyclable in Australia. In the test, it has a different cycling regime due to its different chemistry (two cycles per day instead of the usual three). Like some other models, its BMS doesn't communicate directly with the inverter, so the inverter can only estimate the battery's current state of charge. Instead, ITP was able to implement a system which directly reads the state of charge from the BMS, and uses this to control the battery. The battery is performing without any problems so far. It's too soon to draw any particular conclusions about this battery.

This battery has run without problems, though some inconsistent data for energy discharged each cycle suggested a possible fault. However, the manufacturer has said there is no fault apparent with the battery and ITP adjusted the cycling range after clarifications from GNB on the battery's charge limits. Since then it has continued to operate and the calculated battery capacity has slightly improved.

The Sonnenschein lead-acid batteries have had several problems in the test. Their overall capacity has reduced, and the SMA inverter has struggled with accurately estimating the state of charge of the battery resulting in the batteries not being fully charged and discharged as often as they should be. The test program may be exacerbating the battery's decline, as lead-acid batteries are not as suited to accelerated cycling as lithium batteries. Testing for this battery has concluded.

This battery developed a fault early in the test, when it apparently entered a low-voltage protection mode and shut down. However, it appears to have continued powering its internal components, to the point where its charge had reduced too far for it to be safely recharged again. No conclusions could be made from the small amount of data obtained. Testing for this battery has concluded.

This early model LG Chem battery shut down multiple times during the 2018/19 summer temperature tests, suggesting a problem with operation in hot weather, though this has probably been exacerbated by the accelerated cycling program. Up to this point it had shown high reliability and had achieved among the highest number of cycles in the test. LG Chem batteries have comparatively high energy density and therefore can't dissipate heat as readily as other models. In normal operations they're less likely to have problems in hot weather than shown in the test. Ultimately LG Chem decided to replace this sample as it had developed faults. The replacement is a newer model RESU 10 as the older model is no longer available. Testing for this battery has concluded.

This battery operated OK for nearly one year, until September 2018 when it would not restart after a scheduled outage. Inspection determined that the battery voltage had dropped too low and that had resulted in swelling of the battery cells. The battery was replaced with a new sample in October 2018, and the replacement sample has operated without problems. Capacity appears to be about 80% of the original value after 1430 cycles.

This battery is a rack-mounted modular system, made in Australia (using imported battery cells) and was installed in 2020 as part of Phase 3. Like some other models, its BMS doesn't communicate directly with the inverter, so the inverter can only estimate the battery's current state of charge. It appears that the battery depends in the inverter to do this accurately, or at least conservatively, as the battery warranty depends on it not dropping below 20% charge. ITP's experience indicates that it's hard for the inverter to do this, and while no operational problems have been found so far, the battery is delivering much less energy per cycle than its claimed capacity. Time will tell more.

This battery has had no problems in the test, and so far is showing good capacity retention of about 80% after 2250 cycles.

The Redflow battery is another interesting non-lithium battery, being a "flow" battery that uses a pumped zinc bromide electrolyte liquid to store and release charge. Unfortunately, the tested samples have suffered several electrolyte leaks or contamination and the battery has been replaced four times over the course of the trial. Redflow identified manufacturing and transport issues as the cause of these problems and have modified procedures since then, and expect the problem will be avoided in future. Due to the various replacements of test samples, the current sample of the battery has only been through about 860 cycles since February 2019, and has operated without problems and only minor capacity fade so far.

This battery (now sold under the brand name Hansol, a Samsung partner) proved very reliable since being installed in 2016 in Phase 1 and had no operational issues until late 2020, when it started to need frequent manual resets, and other problems such as power oscillations began to appear, which are probably due to the battery suffering from aging. As a result, ITP decided to conclude testing for this model. It completed more cycles than most other tested batteries. 

After this battery had been cycling for approximately one year, SimpliPhi advised that their recommended inverter settings had changed from the original set-up, and that the discharge cycles had drained the battery too far. They collected the tested battery but decided to issue a refund rather than a replacement, so this brand is no longer in the test.

The SolaX battery has been cycling reliably since being installed in 2020 as part of Phase 3, but the energy and state of charge discharged per cycle has started to drop off rapidly. ITP has reached out to SolaX and is awaiting a response after they complete their investigation. The data so far indicates that after about 880 cycles, the capacity has dropped to 88% of its original value.

This battery by the German company sonnen consists of a modular all-in-one unit comprising battery cell modules, BMS and inverter, and was installed in 2020 in Phase 3. Sonnen has established a manufacturing plant in South Australia. ITP had some initial issues with controlling the battery when it was commissioned, but since then it has operated without any problems. It's too soon to draw any particular conclusions about this battery.

This battery was installed in Phase 1 and is still running well. It has had no problems in the test, and so far is showing excellent reliability and capacity retention. Unfortunately, it appears to no longer be available in Australia.

This sample of the first-generation Tesla Powerwall proved challenging to control for testing purposes, as it's not compatible with the SMA inverters used in the test lab. A Solar Edge inverter was used instead. While ITP was able to control the Powerwall to some extent, their only option was to have the Powerwall charge and discharge at its maximum rate, which is not ideal and may be accelerating its capacity fade. Nevertheless, this Powerwall performed reliably and in line with its claims, with no operational problems, until it failed to restart after a planned shut down in 2019 (due to construction work in the lab). The fault appears to be that the inverter didn't start the battery up correctly, or the battery was unable to charge due to a failed cell. At the time of its demise, the Powerwall appeared to have 59% of its original capacity, after 2540 cycles.

Similar challenges were encountered as with the original Powerwall above. Also, a fault occurred with the first sample delivered to ITP (this was replaced by Tesla). The new sample has been on test since November 2018 and is running well, with an apparent capacity of about 85% after 1690 cycles.

Zenaji is an Australian company, and their Aeon battery uses a different lithium chemistry to most other batteries: lithium titanate. This promises to have excellent thermal safety and a long lifespan, which is why they warrant the battery for 20 years or 22,000 cycles. It also has the ability to deliver its stored energy very quickly when needed. The battery system is modular and includes a BMS – it's assembled in Australia but the cells are imported. Like some other models, its BMS doesn't communicate directly with the inverter, so the inverter can only estimate the battery's current state of charge, and it appears the inverter can't do this accurately. This means it is difficult to cycle the battery as per the usual three cycles per day, and the battery is not delivering the full energy is apparently has stored. Zenaji has recommended using a different inverter, but one that ITP doesn't have the ability to use in the lab environment. The test will continue as is for now, until a more suitable inverter can be installed. Apart from the above issues that mean any capacity fade is hard to measure, the battery is operating without problems, and it's too soon to draw any particular conclusions about it.