{"id":6041,"date":"2016-06-01T15:50:24","date_gmt":"2016-06-01T06:20:24","guid":{"rendered":"http:\/\/www.solarquotes.com.au\/blog\/?p=6041"},"modified":"2024-10-02T11:19:35","modified_gmt":"2024-10-02T01:49:35","slug":"redflows-zinc-bromide-zcell-battery-may-have-the-edge-over-lithium-ion","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/redflows-zinc-bromide-zcell-battery-may-have-the-edge-over-lithium-ion\/","title":{"rendered":"ZCell Battery Review: Better Than Lithium-ion?"},"content":{"rendered":"
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How does the Aussie Redflow ZCell compare to lithium ion batteries?<\/p><\/div>\n

Note:<\/strong> the Cell battery has been superseded as Redflow continuously improves its product. The latest version of Redflow’s battery is called the ZBM3.<\/em><\/p>\n

The Australian company Redflow<\/a> is accepting pre-orders for its new home energy storage system, the ZCell<\/a> battery.\u00a0 It has a 10 kilowatt-hour usable storage capacity<\/a>, can provide 3 kilowatts of continuous power, and is suitable for on-grid and off-grid use.\u00a0 Deliveries will begin in August 2016.<\/p>\n

In this Z-Cell battery review I go deep into the zinc bromide technology’s pros and cons compared to its main challenger: lithium ion batteries.<\/p>\n

While there are many lithium-ion storage systems<\/a> on the market, the Redflow ZCell stands out as the only zinc bromide flow battery<\/a>.\u00a0 Its unique chemistry gives it several advantages over lithium-ion systems.\u00a0 One is it can lie dormant for long periods at any level of charge without suffering from deterioration.\u00a0 And another is its storage capacity will never decline over its over its entire lifespan.\u00a0<\/p>\n

Multiple ZCell batteries can be installed to provide additional power and storage capacity. It is designed for outdoor installation and weighs 240 kilograms. It will come with a comprehensive product warranty of 10 years or 30,000 kilowatt-hours, whichever comes first.\u00a0 If fully cycled once each day it will take 8.2 years to reach the end of its warranty.\u00a0 As most households are unlikely to use it at full capacity, many people could buy a ZCell and be confident they won’t be out of pocket if a fault develops for 10 years.<\/p>\n

Is A Zinc Bromide Battery As Good As You Zinc, Bro?<\/h2>\n

The chemistry of the ZCell battery is very interesting.\u00a0 It is, at its heart, a reversible electroplating machine. When the ZCell is charged, electrical current is sent through the battery which causes zinc<\/a> to be removed from zinc bromide<\/a> and electroplated onto plastic electrodes. When the battery is discharged, the opposite happens and zinc is removed from the electrodes and attached to bromine<\/a> to make zinc bromide and an electrical current is produced.<\/p>\n

So, yes, I’ve pretty much said you can run a battery off cheap jewellery and galvanized iron.<\/p>\n

The chemical process is completely reversible, which means the ZCell battery’s energy storage capacity never declines. Unfortunately, it will stop working at some point, but, fingers crossed, not for a long time.<\/p>\n

Are Zinc Bromide Batteries Safe?<\/h2>\n
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Zinc Bromide is Toxic<\/p><\/div>\n

Is zinc bromide safe to handle? Hell no! It’s toxic. If you drink that stuff, you’ll die. However, you will be safe if you remember to follow this one simple safety procedure: Don’t drink zinc bromide. If you can manage to do that, you should be fine.<\/p>\n

There are about 125 liters of reddish hued zinc bromide solution, at 20% concentration, that weighs around 150 kilograms in the ZCell battery. And if I remember my high school chemistry correctly, and yes, I am so lazy I would rather try to remember something I learned a zillion years ago than actually bother to type something into Google, the more dilute it is, the less dangerous it is.\u00a0 And so the fact that it is mostly water is great news if you decide to splash it on like some sort of toxic aftershave. It should really reduce the irritation.<\/p>\n

But unless your hobby is shooting rifles at random objects in your backyard, you should never come into contact with the zinc bromide solution.\u00a0 The bromine that is formed when the battery is charged is stored as an oil inside a thick polyethylene tank inside another thick polyethylene tank.\u00a0 The zinc bromide is kept in the outer tank.\u00a0 And the entire battery sits in a metal enclosure which has another tank designed to catch any fluid in the unlikely event that leakage does occur.<\/p>\n

Zinc bromide solution doesn’t evaporate easily, so if it is spilled it will just tend to sit there.\u00a0 But it is likely to give off a small amount of bromine gas and this gas could also be potentially released directly from the battery.\u00a0 However, this gas comes with its own built in safety system. Bromine comes from the Greek word br\u00f3mos, which means stench. So if there is leaking bromine gas you will know about it and you won’t want to hang around.<\/p>\n

Zinc bromide is not a teratogen. This means two things. Firstly, it is not a monster from Doctor Who. And secondly, it does not cause birth defects. In other cheerful news, it does not cause cancer. Or at least it doesn’t cause more cancer than stuff we normally don’t consider to cause cancer such as vegemite or wood.<\/p>\n

I could go on about its health effects and exactly how much zinc bromide solution you can drink before you need to call an undertaker, but I don’t think that would really be fair on the flow battery. After all, I don’t tell people not to break open their lithium-ion batteries and eat the insides. And I also don’t warn people not to drink petrol or shower in it. So basically, what you need to know is, the ZCell battery is not bloody likely to emit bromine gas. If it does emit bromine gas you’ll bloody well know about from the stench. If it somehow leaks zinc bromide out of both the battery and its enclosure, you’ll know about it from the literally bloody colour. And I’ll assume you’re not bloody stupid enough to try to lick it up.<\/p>\n

Every time something new comes out people have a bad habit of focusing on any potential negatives, while ignoring the fact that everyday activities such as driving a car are far more dangerous than installing a zinc bromide or lithium-ion battery.<\/p>\n

We shouldn’t fear the new. Except for babies. Those things are terrifying.<\/p>\n

The ZCell Never Declines In Storage Capacity<\/h2>\n

The ZCell battery can be discharged 100% every single day without suffering any harm at all, which is very different from other battery chemistries on the market.\u00a0 In addition it does not decline in storage capacity over time.\u00a0 It starts off with 10 kilowatt-hours on the day its first turned on, and it will have 10 kilowatt-hours on the day it dies.\u00a0 And according to Redflow, for a family that uses it at 80% capacity, that’s likely to be around 14 years later.<\/p>\n

In comparison, the Tesla Powerwall is a 6.4 kilowatt-hour battery and only 5.44 kilowatt-hours of that is actually warranted to be usable<\/a>.\u00a0 But after the first 2 years that drops to 4.6 kilowatt-hours.\u00a0 And 3 years later it drops down to only 3.8 kilowatt-hours of warranted storage. So after 5 years it would take 3 Tesla Powerwalls to\u00a0have the same warranted\u00a0energy capacity as the ZCell.<\/p>\n

While the Tesla Powerwall is the poster child of not being able to keep its kilowatt-hours up, every battery that isn’t a flow battery like the Redflow ZCell will decrease in capacity over time.<\/p>\n

The ZCell Can Rise From The Dead<\/h2>\n
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The ZCell can rise from the dead<\/p><\/div>\n

At any point when it is charging or discharging the ZCell battery can be put into hibernation mode and be left as it is for as long as you like without suffering any harm.\u00a0 And it will maintain whatever charge it had at that point for potentially decades.\u00a0 This is very different from other battery chemistries which will gradually lose charge if alone and deteriorate once they’re completely drained.<\/p>\n

However, the Redflow ZCell can raise from the dead 3 days, 3 months, or 3 years or more later and continue operating as if nothing had happened.\u00a0 Some external power will need to be supplied to get them going, but not much.\u00a0 For an off-grid system<\/a> a hand crank should be sufficient.<\/p>\n

This ability to completely shut down at any time without harm and without losing stored energy makes them ideal for applications where they might only be used occasionally, such as holiday homes or seasonal businesses.<\/p>\n

The ZCell Is Very Unlikely To Start A Fire<\/h2>\n

The good news is bromides are a flame retardant, so unlike lithium-ion batteries, the electrolyte is not flammable. The bad news is if there is a serious fault it is still potentially possible for the battery to give off hydrogen, which is explosive and doesn’t give a damn about flame retardants.\u00a0\u00a0 However, the chances of the ZCell giving off a dangerous amount of hydrogen when installed in an outside location appears extremely small to me.<\/p>\n

If you are wondering where hydrogen can come from in a zinc bromide battery, the electrolyte solution is mostly water which will produce hydrogen when current is passed through it.<\/p>\n

Operating Temperature<\/h2>\n

The ZCell battery operates with an electrolyte temperature from 15 to 50 degrees Celsius, which is not the same as ambient air temperature.\u00a0 If the temperature of the electrolyte falls out of this range the battery will shut down, but won’t be harmed.<\/p>\n

Because the ZCell has a lot of thermal mass, generates heat when charging and discharging, and has a fan to blow off excess heat, I wasn’t sure just what this meant for its operation in different Australian climates, so I called Andrew Kempster, the Sales Director of Redflow, and he assured me that provided the installation was appropriate for the location, that is, not exposed to direct sunlight in the middle of Cunnamulla, then the ZCell was expected to function without problem in places that are hot in summer, such as central Australia, and cold in winter, such as Canberra.<\/p>\n

Of course, if the ZCell ever does shut down because of low temperatures, just because I said bromides are a flame retardant does not mean it is okay to set it on fire to get it started again.<\/p>\n

The Redflow ZCell Is 100% Recyclable<\/h2>\n

All components of the ZCell are completely recyclable.\u00a0 One could be pulled apart right now and all the plastic and metal could be fully recycled using currently existing methods.\u00a0 The zinc bromide solution can be cleaned and reused in another ZCell.<\/p>\n

Where Is The ZCell Manufactured?<\/h2>\n

Redflow is an Australian company and they designed, prototyped, and tested their zinc bromide battery technology here. However, because Australia’s mining and agricultural industries export so much, it does make it difficult to manufacture things here.\u00a0 As a result, the ZCell is made overseas, under license, by a Singapore based company called Flex, which carries out production in Mexico.<\/p>\n

Flex, or Flextronics, as it is also known, made my original xbox and it still works, so that’s a good sign. But oddly enough, the Redflow website doesn’t say the ZCell battery is made in Mexico. They just say they are made in North America.<\/p>\n

For the benefit of those who don’t speak marketing, I will explain that when companies talk about manufacturing locations, Canada means Canada, the United States means the United States, and North America means Mexico. Why they don’t just say Mexico, I don’t know. After all, I think we as a country have moved past the horrors of the Great Cane Toad\/Mexican War of ’87.\u00a0 And we’re probably not dumb enough to assume the ZCell is full of tequila just because it comes from Mexico.<\/p>\n

The ZCell’s Warranty Is Excellent<\/h2>\n

The ZCell will come with a comprehensive 30,000 kilowatt-hour or 10 year warranty which will cover any faults it may develop in that time.\u00a0 And the warranty covers 100% of the battery’s capacity for that period, unlike lithium-ion batteries which typically only cover 80% of their original capacity, or 56% in the case of the Tesla Powerwall.<\/p>\n

This is extremely impressive.\u00a0 While the ZCell battery only has three moving parts, which are two pumps and a fan, pumps do have a bad reputation for breaking down.\u00a0 However, with proper engineering they can last a long time.\u00a0 My parent’s pool pump has lasted for 15 years. I know this because they keep bringing it up.\u00a0 \u201cWhat’s that, Ronald? You’re out of work again? You know our pool pump has worked reliably for 15 years and we didn’t even pay to put it through university.\u201d\u00a0 Personally, I’ve never had a pump last that long.\u00a0 All my ex-wives used to complain to me about a lack of reliable pumping.<\/p>\n

Expected Operational Life<\/h2>\n

Redflow expects the typical ZCell to exceed its warranty by one third and provide 40,000 kilowatt-hours of stored electricity in its lifetime.\u00a0 If used at full capacity it would take 11 years to reach that point, and if used at 80% of capacity it would last for reasonably close to 14 years.<\/p>\n

Disadvantages Of The ZCell Battery<\/h2>\n

There are a few disadvantages to the ZCell and zinc bromide batteries in general:<\/p>\n