The NationalBattery Test Center has just released report No. 11, describing its third round of battery testing and results.
I will provide details below, but if you want to get a quick look, I can tell you that the new battery is not performing well. Only 2 of the 8 battery brands tested can work normally. The remaining problems range from temporary failures to complete failures.
The 75% failure rate is terrible. Testers purchased these batteries 2 years ago, but I know that unreliable household batteries are still entering the market and use paying customers as unsuspecting Beta testers. This is 10 years after Tesla launched the original Powerwall and started producing modern grid-connected household batteries in Germany at Sonnen.
For anyone who wants to buy home battery storage, the results are frustrating, but you can increase the chance of getting a working battery to more than 25% by using the following two steps...
This will help you avoid disasters and greatly increase your chances of a worry-free experience.
But using a household battery system from a large, well-known manufacturer does not guarantee that it will not malfunction. The National Battery Test Center encountered major problems with major brands. Including...
Most of these failed and had to be completely replaced. However, if needed, the manufacturer will replace your battery system, not the manufacturer who disappears when you need their support.
The fact that most of the batteries tested have major problems only reinforces my previous conclusion from the battery test center report that it is difficult to make reliable household batteries. Â Several manufacturers are working hard to solve the problem, but we need several manufacturers to mass-produce safe and reliable batteries before the price drops. Â
National Battery Testing Center tests batteries. If this surprises you, then you are too accustomed to letting your expectations be subverted, which is why the new Star Wars movie is so bad.
In order to obtain reliability information within a reasonable time frame, they use accelerated testing; the battery can be charged and discharged up to 3 times a day. This allows to simulate up to 3 years of daily riding in one year.
If you want to read the test center report, they are all here. This article will focus on their 10th and 11th reports. My last article on this topic was written 9 months ago, the title is not pleasant...
This article I wrote two years ago revealed that the success rate of the first two rounds of testing was less than a quarter...
This theme three and a half years ago was a Star Wars theme. If you are interested, please describe the testing process...
The first round of testing-the first phase-started in June 2016. This is a graph showing the results:
This graphic is from the National Battery Test Center, but I flattened it to make it fit. If it looks unstable, it is my fault.
Anything in red is bad, and even if there is no red, it does not mean it is good. Eight batteries entered the first stage, but only two were not damaged or failed in some way. A successful battery-GNB PbA-is lead-acid, and this type will not be used for future home battery storage. Although lead-acid batteries are still used in some off-grid installations, they have no hope of becoming cost-effective when used on the grid. Among the six lithium batteries tested, only Sony performed well, and Samsung ranked second, IHT also will pickup the long life cycle lithium battery LifPO4 to household storage.
If the malfunction tracks home batteries like a lion tracks Serengeti’s prey, then in terms of reliability, Sony batteries fight the lions and win. Sony Fortelion is the only first-stage battery system that is still in operation after 6 years. Â It’s not that it just proves that reliable and durable lithium batteries can be made, but we got them in 2016. This battery should be the target of the new battery. It has undergone acceleration tests for more than 6 years and provides the equivalent of daily riding for more than 9 years:
Compared with Sony Fortelion, Samsung AIO performed poorly, only 7.6 years of accelerated testing before failure, but this is still a good result for the Phase 1 home battery system.
I mentioned this battery to illustrate that although LG Chem is a giant organization with a large number of engineering talents, it is not enough to prevent their batteries from suffering multiple problems. When a company like this has difficulty making reliable household batteries, it shows how difficult it is.
This battery, also known as LG Chem RESU 1, failed after only two and a half years of operation. LG Chem replaced it, but did not continue testing. Before the failure, it managed the following:
If its capacity loss continues to be linear, it will reach 60% of its original capacity during the 6-year simulated daily cycle.
The second round of testing started in July 2017. The result is terrible again, as shown in the following figure:
This was also from the National Battery Testing Center, and I squashed it again. But the good news is that I don't have to squash it.
Of the 10 household batteries tested in the second phase, one did not work at all, and only two did not fail in some way. In the two consecutive operations, the GNB lithium-ion battery is over-aging, and is currently equivalent to 4.9 years of daily riding, with a capacity of 47%. This allows only 1 out of 10 battery systems to do what it is supposed to do.
Although it did a good job, it has suffered more capacity loss than Sony Fortelion, even though its cycle times are only 77%. So, while as reliable as Fortelion, this makes Pylontech the second place among all household batteries tested so far.
Compared with the LG Chem LV in the first stage, it managed to retain more capacity. After a daily cycle equivalent to 7.6 years, it is currently expected to reach 60% capacity.
The tester discovered a faulty component in the battery shortly after installation. The system later experienced another failure and was replaced. It's working well now.
The third phase of the test will begin in January 2020. As shown in the picture below, it hasn't been smooth sailing:
Once again, this graphic is from the battery test center, but I don't have to squash it this time! Ah ah ah ah ah! ! !
But there are more failures than the chart shows. Although there is no display problem with 4 batteries, the output energy of PowerPlus Energy per cycle is much less than it should, and the capacity loss of DCS is very fast. This means that only 2 of the 10 household batteries in the 3rd phase test have no problems. They are……
Among the 7 types of lithium batteries (the type most likely to be used for household energy storage), only FIMER REACT 2 has played its due role.
The following is a brief overview of individual battery performance, arranged in rough order from best to worst:
If its battery storage capacity continues to decrease linearly at this rate, it will reach 67% after simulating 10 years of daily riding. As it should.
When I mentioned this battery in the last article, I said that its name reminded me of Fizzgig from Dark Crystal, but now I think it is a Fozzie Bear battery. Anyway, keep going...
The FZSoNick battery is the only sodium chloride metal battery tested. It uses molten salt around 250ºC as the electrolyte, but the insulation is good, so the case temperature is only a few degrees higher than the air temperature. Its disadvantage is that it needs to be discharged to 0% every week. There is no information on how this affects overall efficiency. So far, it has done a good job maintaining capacity:
These batteries obviously won't lose capacity during use, so-fingers interlocked-it may retain 98% of the charge for the rest of its life. The charging and discharging speed of these Swedish batteries is much slower than that of lithium batteries, so it is difficult for households to fully cycle them in one day. Â
I think the possibility that molten salt batteries will be used for household energy storage in the future is very low, but I have been wrong before, so I have reservations about the molten salt statement.
This household battery failed one month after installation, and then failed again a month later. Fortunately, IHT can help it to work again every time. After these initial problems, it performed well:
Failure means that it cannot work properly, but so far, its capacity loss has been very low. More time is needed to see if it will stay low.
It took more than a year to run into problems, and SolaX replaced it with a new battery system. The new one worked well, but it was only tested for a short time. The original management is as follows...
This shows that after about 8 years of daily riding, it will reach 60%.
This PowerPlus Energy battery does not have a direct communication link with its inverter. This means that the inverter controls the battery "open loop" without the benefit of closed loop feedback from the battery. Although this setup works well, the results of previous test centers indicate that it usually does not. Â
In this case, the test center has problems in accurately measuring the battery power. The warranty statement cannot be less than 20%, so uncertainty about the actual power means that this limit may be violated accidentally. The battery system has provided less energy per cycle than its designated available capacity, and can usually only discharge about 5 kWh when it should be able to provide about 7.9 kWh. Than most:
This ran without problems for more than a year, but then the capacity dropped rapidly. Sonnen replaced a battery module and reported that one of the batteries was defective. Replacing modules temporarily increased capacity, but the decline continued. COVID restrictions have apparently delayed fixing the problem. The image below shows that it ran well before the rapid decline, and the temporary improvement after the module was replaced:
As shown in the figure, in the first 800 cycles, sonnenBatterie did not show a significant decrease in capacity.
This is another household battery that does not directly communicate with its inverter. The energy provided by the DCS in each cycle is also less than it should be able to provide. The test center found it difficult to accurately measure the power of the battery system, but its capabilities seem to be rapidly deteriorating:
If it continues at this speed, after approximately 3.5 years of simulated daily riding, its capacity will drop to 60%.
The battery also has no communication link with its inverter. The paired SMA Sunny Island inverter is recommended by Zenaji, but it cannot accurately measure the power in the battery system. This has caused the battery to generally provide less than half of the energy it should be able to provide in each cycle. The test center has been unable to estimate how much its battery capacity may have dropped.
Zenaji has since removed the SMA Sunny Island from its list of compatible inverters, but it is too late for the National Battery Test Center. Fortunately, families are protected by Australian Consumer Security, which requires products to be "fit for purpose". This means that you are buying household battery storage from any supplier, and they say it can be used with the inverter, but not, you are entitled to remedy. This may be repair, refund or replacement.
Post time: Dec-08-2021
