Using your SoNick battery, energy storage system in winter

During summer, when you have an energy storage system on your house, as long as it is sized correctly and you have enough solar PV, you should always be able to fill your batteries to full capacity on a daily basis. You will probably generate excess electricity and export it to the grid, although you will rarely be paid enough to justify this as a useful use of your green energy production system.

In summer, you can generally just ignore your energy storage system and it will cover as much of your power needs as you have designed the system to provide.

However, in winter the situation changes as the hours of solar generation decrease and the sun is lower in the sky, so often produces less PV generation on your solar panels. This is particularly relevant when you have several days in a row of rainy and / or cloudy weather with little to no PV generation. In order to maximise the solar PV available and get the most use from your batteries it may be a good idea to change the way your battery is utilised.

Instead of only filling your battery from solar which is the cheapest and most environmentally friendly way to fill a household battery you can fill it using off-peak power then using the battery system to provide electricity to your house during peak power usage times, often 3 – 9pm each day. Not as good as charging the battery with the sun but better than paying peak electricity rates.

This is especially relevant if you have a green energy provider who allows you to purchase green power when you can’t provide your own green power.

If you know the weather for the next day or next few days will be rainy and / or cloudy you can set your battery system to charge overnight and turn off the “keep batteries charged” option the next morning. Alternatively, you can turn the option on in the morning if you see the weather is unlikely to charge the batteries and turn it off before peak rates kick in during the afternoon.

This may take a little more effort but can reduce your winter energy costs. This process also depends on what batteries and inverters you have in your system. Not all battery providers will allow you access to the inverters to allow you to adjust settings.

It is best to check with your battery installer to make sure your system is capable of these adjustments and you have access to your VRM to do so.

We will describe here how you can maximise your winter power and make the best use of your energy storage battery if you have a SoNick battery and are using a Victron inverter.

Your Victron inverter has an option that allows you to “keep batteries charged” which will charge up your batteries from the grid if the solar panels don’t produce enough generation to do so. On your VRM dashboard on the top right-hand side there will be a small square icon that allows you to access the control menu. This icon may take a few seconds to show up after you have accessed your dashboard.

Most of the time your Victron inverter will be set to “optimised without battery life”.

However, if you have access to off peak power and are able to spend a small amount of time adjusting your inverter you can change this setting to “keep batteries charged”.

Most electricity providers provide both peak and off-peak rate times. This may change depending on the state and time of the year. In Victoria, most energy providers now have standardised Peak and Off-Peak times across all the networks without shoulder rates. The new time of use periods are: For Residential: Peak = 3pm – 9pm all days, Off-peak = all other times.

To activate “keep batteries charged”, click on the small circle to the right of the statement “keep batteries charged”. You will then see a small countdown timer that says “keep batteries charged will be enabled in 5 seconds”. Once the countdown has completed and “keep batteries charged” is enabled the battery will charge from the grid using off peak power to charge up the battery if there is not enough solar PV to charge the batteries on their own.

As most energy storage systems are set to use solar for household use first and only store excess generation in the batteries this should not increase your electricity usage on top of what you would have been already using.

You must remember to reverse this process before peak rates kick in so that if the battery isn’t fully charged you aren’t charging it using peak-rates which would defeat the purpose.

The added advantage of using this process is that batteries can become 100% charged which can be difficult to do in winter. Most batteries operate better if they are charged to 100% capacity on a weekly or fortnightly basis. Although it doesn’t apply to the SoNick warranty some battery warranties actually have this as a requirement.

Another reason to utilise this method of keeping your batteries charged in winter is that rainy and windy weather is the most likely weather for energy blackouts. If you have a fully charged battery, you will still have power when the grid goes down when many of your neighbours may not (as long as your battery is wired to provide power when the grid goes down).,

If you have been notified of a planned outage in your area you can make sure your battery is fully charged before the outage, meaning there will be no interruption to your electricity supply.

In terms of protecting the overall power grid the less power you are using during peak times the better it is for people who can’t afford to install renewables and better for the stability of the grid, If you would like to know more about getting a safe, reliable and recyclable battery energy storage system for your own home, business or micro-grid to increase your energy independence visit us at We have a number of different sized systems that can cater to your budget and household needs.

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