Salt Battery technology

Why Salt?

Sodium Nickel Chloride batteries are made out of ‘table salt’ – it’s plentiful, easy to access and, as you’ll discover makes for an incredibly good battery electrolyte with an incredible energy density – as good as any other available technology.

Just some of the benefits to this amazing technology in an easy to digest graphic:

Sodium Nickel Chloride battery chemistry

The heart of the SoNick battery is Sodium Chloride as the positive electrode and Nickel as the negative electrode, with a ceramic separator in between.

The battery is heated until the salt turns molten, around 250oC and that’s when the magic (or should we say chemistry!) happens.

The store of charge results from the conversion of: 2NaCl + Ni into NiCl2 + 2Na.

Really that’s it. Nothing toxic. Nothing exotic. Fully recyclable. Energy from Salt.

And there’s no memory effect, ie the battery components don’t degrade.

SoNick Fire Safe Chemistry

Is it safe having something that hot? Absolutely!

The battery core is wrapped in some serious insulation, so that the outside of the battery is only a few degrees above ambient temperature.

FZSoNick obtained UL9540A certification for the SoNick battery, which means there is no possibility of fire or explosion leading to thermal runaway. Very few batteries have this certification. Think of the battery as being designed to withstand extreme temperatures rather than being at risk from them.

In one stress test, the battery (without the BMS) was placed on a fire… and it didn’t explode or catch fire.

It was even shot with a shot gun, which penetrated the shell, and only a small amount of hot molten salt came out, which quickly cooled. It’s worth noting that shooting the battery with a pistol did not penetrate the solid steel casing, and it did not explode. Nor did it explode when dropped from 2.1m high.

(We DO NOT recommend trying any of the above tests with your battery yourself, it will void your warranty!)

Sodium Nickel Battery safety comparison

Operating Temperature

One of the unique features of the SoNick battery is the incredible operating temperature range. It’s a very under appreciated aspect of battery management.

Most batteries degrade in performance outside of their ideal temperature range, and the performance information they show is for ONE temperature, most commonly 25oC.

The SoNick battery is different.

There is NO degradation in performance between -20 and +60oC. In fact most batteries will only function between +5 and +40oC.

This occurs exactly because the chemistry inside the battery works at such a temperature, the battery keeps the ideal chemistry temperature inside its core.

This means when it gets cold, even really cold, your SoNick battery does not need heating and works perfectly without degradation.

When it gets hot, your SoNick battery does not need cooling and works perfectly without degradation.

Sodium Nickel Battery operating temperature comparison

The Battery Management System

There’s also a very good battery management system (BMS) on the front of the battery that manages the battery.

The BMS makes sure you cannot over charge the battery and limits the input current to the perfect Amps. Basically the BMS does a lot to protect the battery for you.

It also records everything that happens to the battery, giving you a wealth of data if you need it, and makes warranty claims straight forward.

The BMS makes connection to an inverter very simple and gives you full remote visibility and monitoring over the performance and health of the battery.

(Note that remote monitoring isn’t a warranty requirement, unlike most Lithium batteries).

The Sustainable Battery

The simple composition of the battery make it completely recyclable. Any facility that can recycle Lead Acid can recycle a SoNick battery.

And all raw materials are abundantly available worldwide. In the search for the right suppliers, great attention was paid to high quality, clean raw material extraction and the shortest possible transport routes.

The battery is manufactured in Switzerland and is composed of:

  • Salt sourced from Swiss saltworks
  • Iron sourced from Europe
  • Nickel sourced from England & Canada
  • Ceramics sourced from England & Japan

In the recycling process, there are many industrial uses for the iron and nickel. The ceramics (essentially clay) and salt have a wide variety of uses in building materials, eg road construction.

When its recycled, the raw materials from the battery are worth more than the effort it takes to extract them.

This means it’s economically attractive to recycle

This is very different for Lithium batteries, where the difficulty in extracting and managing the materials for recycling make it only economically viable with subsidies. The cost of lithium ion batteries would be substantially more or if end of life costs were to be factored into the price (this has become law in some overseas countries already).

Combine this with the constant performance and long life (there are STILL batteries operating at 100% capacity that were activated in 2006 when FZSoNick started commercial production), and you have the most sustainable battery on the market.

Size and Energy Density

The SoNick battery is very compact for its size. The Gravimetic Density of our most commonly used battery the TL200 is 91Wh/kg. This is comparable to the best batteries in the business.

And the weight… we’ll let the graphics do the talking:

SoNick battery weights comparison

Some special SoNick features

There are a few amazing – and in some cases unique – features of the SoNick batteries that are worth mentioning.

Add a new battery at any time

If your energy demands increase, you can add in an additional battery without effecting the performance of your system. Most other chemistries do not have this feature.

Doesn’t lose charge when stored

The SoNick battery doesn’t lose its charge when it’s stored. Even if you turn it off (the core cools and salt solidifies), you can store your SoNick for years, and when you turn it back on it will have the same charge as when you turned it off!

Long Shelf life

If a SoNick battery isn’t turned on, it can sit on the shelf for years, and when activated be as fully functional for just as long as when it was put on the shelf in the first place. The chemistry is truly inert when it’s not heated up.

No Maintenance

With a SoNick battery, there’s no maintenance required. Just keep it out of the sun and rain and keep it connected to a circuit and it will just work, and keep on working and working and working.


The SoNick battery has a range of certifications as well as the UL9540A one. For a quick summary:

Sodium Nickel Battery certifications image

Or you can take a look at the full list and certificates here if you’re interested.

So is it expensive?

No. The SoNick used to be expensive, but not anymore.

However with the rising demand for and cost of Lithium, it’s now priced in the mid range of good Lithium Ion batteries.

You can absolutely get batteries a lot cheaper but we’d really really really recommend you don’t get these. Nearly everyone who does regrets it.

We’re increasingly having customers come to us who had a cheap Lithium Ion solution installed in their home and are looking for something different, something better.

Are there any disadvantages?

Not really, however there are some features that are different to other batteries or other batteries are better for a particular application. These are:

  • It takes around 9 hours from first activation until the SoNick is ready to get to work as it needs to heat up the core of the battery
  • The battery cannot be placed vertically on a wall (although with it’s small foot print this rarely matters)
  • If the chemistry is active the battery needs to be have a current running through it to maintain its core temperature, even a PV cell generating no discernable charge is enough. If it doesn’t have this it will begin to consume its own change, eventually reaching zero charge and turning off.
  • It won’t get small enough to be inside your phone!
  • It doesn’t have as fast an initial draw down current as Lithium – however it can sustain a large draw down current longer than any other battery.

It’s always important to do your own homework and ensure you’re getting the best battery for your needs and priorities.


If you’ve made it this far, congratulations on taking a crash course in the SoNick battery technology!

Here’s a quick summary version:

SoNick battery features:
  • UL9540A certified
    > Non flammable
    > Non explosive
  • Full operation from -20°C to +60°C
  • High energy density
  • No degradation of capacity
  • 100% recyclable battery
  • No dangerous materials
  • No memory effect
  • No maintenance
  • Long Life
  • Made in Switzerland

From here, take a look at the product or solution that fits you best and let’s get a SoNick battery into your hands!

Our Products

Whether we’re building your system from the battery upwards, or delivering a customisable off the shelf solution, we’ve got you covered. See our product solutions we’re building with our partners, and the batteries that power them:




Or, if you’ve read this and still got questions, here’s how to get in touch: