Best battery energy solutions to solar power Australia
Energy storage for a clean energy future

Energy For a sustainable future

Energy storage for a clean energy future
Contact GridEdge

FAQ

Email address for GridEdge battery storage

Home Page

What does Depth of Discharge or DOD mean?

 

When you see information on batteries you often see their performance talked about as their Depth of Discharge or DOD. This is the percentage of battery capacity that can be used.  For some batteries you can use 80 or 90% of their capacity but others only allow you to use 30%. It is very important to understand this when you are looking at the output of any battery.

 

You can have a range of batteries, all having 10 KW capacity but if one battery has a DOD of 80% where you would actually have 8KW of available storage another one might have a DOD of only 30% which means you would in fact only be able to use 3KW of storage. This means the lower the depth of discharge the more batteries you would need to achieve the same storage capacity.

 

You can’t fully discharge batteries for various reasons but largely because it affects the chemistry of different batteries in different ways. For example most lead acid batteries have quite a low depth of discharge, often around 30%. If you take more out of the battery than 30% the chemistry of the battery starts to deteriorate. You will often hear people complaining that they have to replace their lead acid batteries every couple of years and this can be one of the reasons why. At the same time at the opposite end of the scale Sodium Nickel and zinc bromide batteries can actually be discharged to 80 – 90% of their capacity without deterioration to the battery chemistry.

 

See more information

What does Number of Cycles mean to your Energy Storage Battery?

 

When you see information about batteries one thing you will often see is the number of cycles they will claim to be able to provide in their lifetime. This figure can be anywhere from 2,000 cycles to 5,000 or even 6,000 cycles.

 

At first glance it might seem that the higher the number of cycles, the better the battery will be but in fact there are many factors that can affect the true number of cycles you will get out of your battery over its lifetime. Generally the more you take a battery below its recommended depth of discharge the fewer cycles you will get out of the battery.

 

One cycle is taking a battery from fully charged down to its recommended depth of discharge before charging it up again.

 

Battery specifications usually state a specific depth of discharge per number of cycles expected over a batteries lifetime. This might be 4,000 cycles at a DoD of 80% or 4,500 cycles at a DoD of 30%. If you were to only look at the number of cycles the second example of 4,500 cycles would look like a better option but in fact you would get much better performance from the first battery with fewer cycles as it has a much greater depth of discharge available to be used.

 

See more information

Is your battery toxic to you or your environment?

 

One of the things that you should consider when putting battery storage on your home is whether or not the battery chemistry is toxic either in its manufacture or disposal or in its day to day use.

 

Often, one of the reasons that people put solar panels on their house and put in battery storage to collect the excess usage is to protect the environment and reduce the need for coal powered power stations.

 

This can be counterproductive if you choose a battery that is made from toxic materials or has components that can’t be recycled.

Lithium Ion is a very toxic substance and the mining of it is mainly done in third world countries with dubious safety conditions. There are also a lot of questions regarding its recyclability at end of life due to this toxicity.

 

Lead is a toxic metal with documented health risks.

 

Bromine vapour can be poisonous at room temperature.

 

The FIAMM SoNick battery is made from salt and is completely non-toxic and is also 100% recyclable.

 

Is your battery recyclable?

 

One of the things that you should consider when putting battery storage on your home is whether or not the battery will be recyclable

at the end of its life.

 

Often, one of the reasons that people put solar panels on their house and put in battery storage to collect the excess usage is to protect the environment and reduce the need for coal powered power stations.

 

This can be counterproductive if you choose a battery that is made from toxic materials or has components that can’t be recycled.

 

The FIAMM SoNick battery is  100% recyclable and already has a recycling program in place. The battery materials are recycled to produce stainless steel, the nickel and iron go into alloys and the salt and ceramic are used for road beds.

 

See more information

What is the best operating temperature for your battery?

 

Most batteries will operate, with varying degrees of effectiveness in the 5 – 35 °C range so are fine for the autumn and spring operating months, however if you want a battery that will also operate efficiently in winter and summer you need to understand how temperature has an effect on a batteries operating capabilities.

 

The ambient weather temperatures have a large impact on the performance and on the life of most batteries and unfortunately, it’s a characteristic that isn’t often talked about.

 

The optimum temperature for most batteries to operate at is around 25°C and this is the temperature all battery testing is performed at. When temperatures vary, either up or down there is an effect on the performance and life of most batteries.

 

Depending on the chemistry of the battery different batteries will only operate optimally within a limited temperature range, so it’s important to understand this when purchasing or upgrading your battery for energy storage.

 

See more information

Will your battery operate effectively in hot weather?

 

When the temperature starts to fall  below about 15°C, depending on the battery chemistry, the electro-chemistry of the battery becomes sluggish and doesn’t perform as well. In fact, very few batteries operate below 0°C. This is relevant in many countries in Europe, the USA or Canada but not as relevant in Australia.

 

What is more relevant to the Australian market is the other end of the scale with the hot weather temperatures, particularly those of 40°C or above. Over 35°C, again depending on the battery chemistry, the battery itself will start to degrade. This is why many batteries need to be kept in an air-conditioned environment which adds to the ongoing running costs of the battery and is something that needs to be taken into account when considering the LOC or lifetime cost of a battery.

 

When considering the temperature that the battery is to be used in you must also take into account where the battery is to be stored. A battery stored inside a metal garage will in fact often get hotter than one that is stored outside.

 

The FIAMM SoNick batteries or molten salt batteries don’t have the same temperature limitations as most other batteries as they are designed to operate at elevated temperatures. In fact they have an operating range of -20° to +60°C which makes them a much better alternative to other batteries, particularly in hot environments. In Australia, we have extreme weather conditions and even in a garage in suburbia, a common place for housing a battery, the temperature can often exceed 40°C.

 

See more information

What is your Battery Size?

Battery size comparison

Energy storage batteries come in a variety of different sizes and weights and each have different characteristics. If you have a  lot of suitable space to store your battery this may not be relevant but if you are limited in space you may want to consider one of the smaller batteries.

 

Here is a comparison of some of the most common batteries currently available in Australia with comparisons of size for a similar sized 22kWh system.

 

If there is a possibility of moving house you will need take into account the battery size as well as its weight if you want to move it with you.

 

See more information

 

More coming Soon

Best battery energy solutions to solar power Australia

GridEdge © 2016