SoNick battery replaces lead acid batteries in off-grid installation – case study.

People install battery systems for many reasons and likewise people choose battery technologies for various reasons.

For many years people have used lead acid batteries as a known battery technology, particularly in off grid installations. A battery of choice has often been used Telecom batteries which are replaced regularly from telecom installations that need guaranteed UPS (uninterrupted power supply) capabilities. As these batteries are often sold at a vastly reduced cost it is economical for off-grid households to add a large number of batteries to an off-grid system to allow for reduced capacity of the batteries.

Unfortunately, for lead acid battery systems the battery system operates at the capacity of the weakest battery so you are unable to use new lead acid batteries in older systems and would need to replace the whole bank of batteries when more capacity is needed.

Lead acid batteries are well known for having a “falling off the cliff reputation” and degrading very suddenly and quickly, often with no warning. This happens particularly often in cold or hot weather. Coincidentally this is often when batteries are needed the most for heating and cooling. At the same time, most people who live off grid have learnt to manage their electricity usage to only use what is available and to use a generator when batteries are unavailable.

In this off-grid installation lead acid batteries had been used for a number of years, however they kept needing to get replaced, often every couple of years. Replacing just the faulty batteries in the system had been tried a few times but due to the degradation of the older batteries the new batteries didn’t last very long before performing like the rest of the system.

This installation had to have a dependable power supply so they used a generator when the batteries ran out and this generator usage increased as the health of the batteries decreased. This often meant going outside during the night to manually start the generator to ensure the house had power over night.

The owners of this property had seen the effects of lithium-ion batteries catching fire so didn’t want to use lithium-ion as a replacement for their lead acid system. The area is a very treed area so a fire of any sort could be catastrophic not only for them but for surrounding properties.

The owners had recently visited a friend who had a SoNick battery system installed and were very impressed with the safety and reliability of the SoNick (Sodium Nickel Chloride) battery.

SoNick batteries were selected as they have no fire risk. This was particularly relevant due to their local environment.

As the SoNick batteries operate with no temperature effects and no degradation from -20°C to +60°C there are no issues with either heat or freezing temperatures that are often experienced in rural areas and the batteries don’t require air conditioning to keep them cool or heaters to heat them enough for them to work so more capacity is left to be used in the household.

One of the first comments that was made after the SoNick system was installed was the fact that they could cook, watch TV as well as a use a heater at the same time. Previously these things had to be staggered as only 1 could be used at any time without turning the generator on.

Another advantage of using the SoNick battery system was that it could be programmed to turn on the generator automatically if the battery capacity decreased to a pre specified level. The generator could then be used to fill or part fill the battery before switching off again automatically. This means the generator would be used much more efficiently, only running when it is really needed, further decreasing fuel costs.

Using a battery to replace diesel generators has been shown to decrease diesel use by up to 70% in a number of case studies.

This installation has since had another SoNick battery added to increase capacity due to the success of the installation. Off-grid installations will usually need at least 2 SoNick batteries or 20 kWh of battery storage if it is desired not to use a diesel generator.

Application – off-grid domestic power supply
System Objective – to replace lead acid battery system capable of supplying reliable off-grid power,
Commissioned – June, 2023
Installed PV – 6.75 kW
Battery storage – 19.2 kWh

Although the SoNick battery may have a higher upfront cost per battery, even in large installations, when you consider the lack of degradation, no maintenance, no fire risk, safety of battery and temperature range, meaning no air conditioning required, the cost over the installation’s lifetime is definitely comparable and often cheaper than other battery systems.

If you would like to know more about getting safe, reliable, recyclable, SoNick (molten salt) battery storage for your own home, business or micro-grid application visit us at

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