{"id":7638,"date":"2016-10-03T16:36:09","date_gmt":"2016-10-03T07:06:09","guid":{"rendered":"http:\/\/www.solarquotes.com.au\/blog\/?p=7638"},"modified":"2018-01-17T14:14:30","modified_gmt":"2018-01-17T03:44:30","slug":"new-lg-chem-resu-batteries-smaller-powerful-cheaper-powerwall","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/new-lg-chem-resu-batteries-smaller-powerful-cheaper-powerwall\/","title":{"rendered":"New LG Chem RESU Batteries: Smaller, More Powerful And Cheaper Than A Powerwall"},"content":{"rendered":"
\"powerwall

Smaller, cheaper, more powerful. LG Chem’s new batteries look very compelling compared to a Powerwall.<\/p><\/div>\n

If you are in the market for a home battery and are tempted to buy a Powerwall, then I urge you to also consider the new range of LG Chem batteries announced last week.<\/p>\n

Whilst LG have been unable to compete with Elon Musk for mainstream media coverage, the LG Chem RESU, or Residential Energy Storage Unit for the long winded, has been one of the biggest successes in on-grid home energy storage in Australia. While solid figures are hard to come by, it may have been used in almost half of all on-grid home battery installations.<\/p>\n

While it was popular, ye olde RESU6.4 is no more. LG Chem has replaced it with something better. And not just with an updated version of itself, but with a whole slew of new RESU.<\/p>\n

There are now 5 RESU systems to choose from with nominal capacities ranging from 3.3 to 9.8 kilowatt-hours<\/a>.\u00a0 Three of the new RESU use 48 volt DC power:<\/p>\n

\"LG

The new 48V batteries<\/p><\/div>\n

And\u00a0two use\u00a0around 400 volts (just like a Powerwall funnily enough):<\/p>\n

\"LG

LG’s new 400V batteries<\/p><\/div>\n

The usable capacity of the lower voltage systems is around 90% of their nominal capacity and around 95% for the higher voltage ones.\u00a0 As they are lithium-ion battery systems, their capacity will gradually decline with use and over time.<\/p>\n

The two different voltages allows for a wide range of installation options including DC coupling<\/a> and AC coupling<\/a>.\u00a0 No matter what type of coupling you prefer, you can do it with an LG Chem RESU.\u00a0 And they are suitable for on-grid or off-grid use.<\/p>\n

The 48 volt RESUs have higher power than most comparable battery systems and are lighter and much more compact than the competition.\u00a0 They are warrantied to retain at least 60% of their nominal capacity for 10 years or until they have stored slightly under 2,500 kilowatt-hours for each kilowatt-hour of nominal capacity.\u00a0 Taking an estimate of battery degradation into account this is approximately 3,200 cycles.\u00a0 When cycled once per day it will take around 8 years and 9 months to reach that point.<\/p>\n

The New RESUs’ Vital Statistics<\/h2>\n

In order to save me having to make a table, I have grabbed a screen shots off the new RESUs datasheets<\/a>.\u00a0 Here are the vital statistics for the 48 Volt systems<\/strong>:<\/p>\n

\"The

The vital statistics of the 48 Volt LG Chem RESU battery systems.<\/p><\/div>\n

And here is information on the two RESU that LG Chem refers to as 400 volt systems<\/strong>:<\/p>\n

\"The

The vital statistics of the two 400 volt LG Chem RESU battery systems.<\/p><\/div>\n

Indoors Or Outdoors Installation Is Okay<\/h2>\n

The Enclosure Protection Rating of the RESUs is IP55 which means they are protected against both dust and water. But if dust and water combined their powers to make mud, well, it would be protected against that also. According it its rating it can handle being sprayed with water under moderate pressure from any direction but not immersion.\u00a0 So if you are going to use it on a submarine, try to remember to install it on the inside.<\/p>\n

Maintenance Free<\/h2>\n

Like most new battery storage systems, apart from keeping them reasonably clean, RESU require no maintenance.<\/p>\n

\"exploded

If you have an LG Chem battery NEVER do this to it<\/p><\/div>\n

Round Trip Efficiency<\/h2>\n

LG Chem gives the round trip efficiency of the 48 volt RESUs as greater than 95%, but states this is only under good conditions.\u00a0 In real life I would expect its round trip efficiency to be a little under 95%, especially if it is installed outdoors and often exposed to temperatures above 30 degrees or below 15 degrees.<\/p>\n

The efficiency of the higher voltage RESU will be lower because their built in DC converter will result in additional losses.\u00a0 But since the 48 volt RESUs will need DC conversion anyway, either from a multimode inverter or a separate DC converter, overall their efficiencies should be comparable.<\/p>\n

Operating Temperature is -10 to 45 Degrees Celsius<\/h2>\n

One important piece of information missing from the above tables is its operating temperature.\u00a0 RESUs can function at ambient temperatures from -10 to 45 degrees Celsius.\u00a0 Ambient simply means the air temperature in the immediate surroundings.\u00a0 It is possible that some day we may know why battery manufacturers don’t just say, “local air temperature”.<\/p>\n

The lower limit is not likely to be a problem for Australians, but it is possible for it to shut down during a severe heatwave.\u00a0 To prevent it conking out from heat exhaustion, installing RESUs out of direct sunlight is a very good idea.\u00a0 LG Chem gives its recommended operating temperature as 15-30 degrees, so placing it indoors is probably a good idea and will help improve its efficiency and extend its battery life.<\/p>\n

It’s Quiet<\/h6>\n

The RESUs have no cooling fan and rely on natural convection from its metal case for cooling.\u00a0 This means they are very quiet, which is useful for indoor installation.<\/p>\n

Fire Safety!<\/h2>\n

LG Chem claim that their method of producing battery packs makes theirs the safest lithium-ion battery on the market.\u00a0 I am inclined to believe them.\u00a0 So far, I am not aware of any RESU installed in Australia having safety issues, but since only around 1,000 or so may be installed in Australia at the moment, only time will tell.<\/p>\n

If you are the type of fearless daredevil who leaves a charging laptop unattended on a wooden desk covered in papers, then you are clearly a risk taker who is not going to be worried about installing a lithium-ion battery system.\u00a0 Possibly because they realize how utterly reckless and immune to fear the average Australian is, LG Chem recommends installing RESUs away from flammable materials.<\/p>\n

Nominal Battery Capacity<\/h2>\n

The nominal battery capacity is the total amount of energy the battery can hold.\u00a0 Because completely draining the battery is bad for its lifespan, the usable storage capacity for the three 48 volt RESUs is limited to around 90% of their nominal capacity and for the two higher voltage RESUs it is around 95%.\u00a0 This usable storage capacity will decline over time as the battery is used and will also slowly decline even if it isn’t used.\u00a0 So the moral is, use it or lose it, but using it also causes it to lose it.<\/p>\n

Battery Capacity And Names<\/h2>\n

LG Chem does a good job of matching the names of their RESUs to their nominal capacities 3 times out of 5.<\/p>\n

They start off well, as the numbers in the names of the RESU3.3, RESU6.5, and RESU7H all match their nominal storage capacities.\u00a0 Unfortunately someone must have stamped the names on the RESU10 and RESU10H before they figured out how many battery cells they could actually fit inside them, because they both only have a nominal capacity of 9.8 kilowatt-hours.<\/p>\n

This is a surprising oversight given the care LG Chem appears to have taken with the rest of the product.\u00a0 I suppose it could just be a marketing decision because they decided a RESU10 would sell better than a RESU9.8 but that’s just nuts.\u00a0 How does forcing me to tell everyone you can’t trust the numbers LG Chem puts on their products help their marketing?<\/p>\n

For More Storage Connect Two 48 Volt RESUs<\/h2>\n

An adapter is available that allows any two 48 volt RESU systems to be connected together.\u00a0 So if you wanted you could slap together a RESU10 and a RESU3.3.\u00a0 Although I strongly suggest using the adapter rather than just slapping them against each other.\u00a0 This means the usable storage capacity available to a household from the new systems will range from 2.9 kilowatt-hours with a single RESU3.3 to 17.6 kilowatt-hours from a doubled up RESU10.<\/p>\n

RESUs Are High Power Battery Systems<\/h2>\n

The new RESUs have a lot of power.\u00a0 The “Max Power” figures on the datasheet tables above are the amount of continuous power they can supply when new.<\/p>\n

For on-grid applications higher power improves the economics of battery storage as households will need to draw on grid power less often during the day when electricity consumption exceeds rooftop solar production.\u00a0 It also allows households on time-of-use tariffs to more easily use all the available stored energy during peak periods when grid electricity prices are high.<\/p>\n

For off-grid applications, higher power allows more appliances to be operated at once without tripping the system.<\/p>\n

LG Chem says using RESU at only half their continuous power output level will extend their battery life.\u00a0 In practice most households are likely to use them at an average well below their continuous power output.<\/p>\n

The amount of power a RESU can supply will often be limited by the power conversion device (i.e. battery inverter\/hybrid inverter\/DC-DC Converter) it is used with.\u00a0 Some popular battery inverters\u00a0only allow 2.5 kilowatts of power, which is 83% of a RESU3.3’s continuous power output and 60% of a RESU6.5’s.<\/p>\n

RESUs Have Plenty Of Installation Options<\/h2>\n

There are plenty of options available when it comes to installing RESU.\u00a0 Currently there are 8 compatible mulitmode inverters available that can be used with the 48 volt RESUs and 2 suitable for use with the 400 volt RESUs.<\/p>\n

The 48 volt RESUs could be installed without a compatible inverter by using a DC converter such as the Goodwe GW2500-BP<\/a>.\u00a0 This is suitable for a rooftop solar system<\/a> with a string inverter<\/a> and panels wired up so they produce under 500 volts.\u00a0 The GW2500-BP can only provide 2.5 kilowatts of power, so even the smallest RESU can’t be used at full continuous power when installed this way.<\/p>\n

The 400 volt RESUs can also be installed without a compatible inverter by using a battery-inverter<\/a>.\u00a0 An example of one of these is the Sunny Boy Storage<\/a>.\u00a0 This particular battery-inverter will also limit the RESU to 2.5 kilowatts of power.<\/p>\n

The Most Compact Battery Systems Available<\/h2>\n

LG claims the RESUs are the most compact and energy dense battery systems available and I believe them.\u00a0 The RESU6.5 takes up less space than my microwave oven while only being 12 centimeters thick which makes it very easy to find room to install it.\u00a0 At 52kg it is not exactly light, but it is lighter per kilowatt-hour than all the other battery systems out there.\u00a0 Much lighter in some cases<\/a>.<\/p>\n

If you are short of space, a RESU is an excellent choice.\u00a0 It also makes it easy to install inside which can help extend its life by avoiding high temperatures.\u00a0 Unless perhaps your house is an oven in the summer.<\/p>\n

LG Chem Battery Technology<\/h2>\n

Lithium-ion battery cells are very thin and are manufactured in long ribbons.\u00a0 Because enormously broad but extremely thin and thus fragile batteries aren’t very practical, there are three methods used to make them more manageable.<\/p>\n

The first is to roll them into\u00a0 cylinders and this type can be found in power tools, Tesla cars, and laptops1<\/a><\/sup>.\u00a0 Their drawback is whenever you stack cylinders together there will be spaces left between them.<\/p>\n

Cells can also be folded into a flat rectangular shape like a long scarf.\u00a0 This reduces but does not eliminate the amount of dead space.<\/p>\n

Unfortunately both rolled and folded cells can distort over time due do expansion and contraction caused by changes in temperature and this can affect their performance.<\/p>\n

LG uses the third method, which they call lamination and stacking, where they don’t roll or fold but cut the cells into sheets and stack them flat on top of each other.\u00a0 This eliminates dead space and minimizes distortion, contributing to energy density and battery life.<\/p>\n

Here is an LG Chem video<\/a> of their batteries being made by robots.\u00a0 With all that automation, now is clearly not a good time to get a job in a battery factory, despite rapid expansion in capacity.<\/p>\n

Warranty And Battery Degradation<\/h2>\n

No matter how they are made, lithium-ion batteries degrade with use and slowly decay even when not used.\u00a0 The RESU warranty<\/a>, while better than some others<\/a>, reflects this.<\/p>\n

The 48 volt RESUs’ warranty promises they will still have at least 60% of their nominal capacity after 10 years or until they have stored a total amount of electricity just under 2,500 kilowatt-hours for every kilowatt-hour of nominal capacity.\u00a0 This comes to:<\/p>\n