How a SolaX Battery System Works

A SolaX battery system is SolaX equipment that works as one: the HS51 battery, a SolaX hybrid inverter and, if you want it, SolaX's Binary charger for your car. This guide explains what each piece does, which inverter suits your home, what happens in a blackout, and what SolaX's warranty covers. The figures come from SolaX's own Australian datasheets, manuals and warranty terms.

The Short Version

• The hybrid inverter is the brain. It runs your solar panels, the battery and your backup power from one box.
• The HS51 battery stores spare solar for the evening, in 5.1 kWh modules.
• The Binary charger is optional. It charges your car from solar, and with a car that has vehicle-to-load, it can send power back to run the house.
• Single phase home: the X1-VAST. Three phase home: the X3-HYB-G4 PRO, or the X3-ULTRA for a bigger property.

The Three Pieces

1. 1

   The SolaX hybrid inverter

   "Hybrid" means it handles solar and a battery together. It turns your panels' power into power the house can use, decides when to charge and when to use the battery, and switches the house to backup when the grid fails. There are three to choose from, depending on your home: the X1-VAST, the X3-HYB-G4 PRO and the X3-ULTRA.

2. 2

   The SolaX HS51 battery

   A tower of 5.1 kWh modules, from two (10.2 kWh) up to ten (51.2 kWh) in one tower. It uses LFP (lithium iron phosphate) cells, is IP66 rated, which means sealed against dust and strong jets of water, and has fire suppression built in. It doesn't work on its own: it plugs into the SolaX inverter.

3. 3

   The SolaX Binary charger (optional)

   A home EV charger that works both ways. It charges your car at 1.4 to 22 kW, and with a car that has vehicle-to-load (V2L), it can feed up to 7 kW from the car into the SolaX inverter to help run the house.

Which Inverter Suits Your Home

Most of the choice is made by your power supply: single phase or three phase. We check that at your switchboard before we quote, so you don't need to work it out yourself.

"Most solar panels" is SolaX's limit of twice the inverter's size in panels. How much you actually fit depends on your roof and on what Energex approves for your connection. The X3-ULTRA starts at 15 kW, and SolaX makes it for businesses as well as homes, so it suits bigger properties. There's more detail on our SolaX hybrid inverters page.

A Normal Day

Day to day the inverter runs in what SolaX calls Self use mode:

1. Daytime: your solar runs the house first. Spare solar charges the battery, and once the battery is full, the rest goes to the grid.
2. Evening and night: the battery runs the house until it reaches the minimum level set on the inverter. Then the grid takes over.
3. Next morning: the sun comes up and it starts again.

The inverters have other modes too, such as a Backup mode that holds more charge in reserve for outages, and a time-of-use mode that charges and uses the battery in time slots you set.

What Happens in a Blackout

This is how SolaX's Australian datasheets and user manuals describe it:

• It switches by itself. When the grid fails, the inverter moves to backup in under 10 milliseconds. SolaX calls this UPS-level switchover.
• Your solar keeps working. On backup, solar runs the house first, extra solar charges the battery, and the battery covers the rest. You need the battery for this: SolaX rates the backup output with a battery connected.
• Whole home or chosen circuits. SolaX's Australian wiring guides show both. With whole-home backup the whole switchboard stays on; with partial backup only the circuits you pick do. SolaX says the X1-VAST can back up the whole home, up to 63 A, without extra devices.
• There's a limit on how much runs at once. On backup the inverter supplies up to its own size, with twice that for 10 seconds to get motors going. SolaX notes a fridge needs three to five times its running power to start, and an air conditioner three to six. If the house asks for more, the inverter reports an overload until something is switched off.
• When the battery runs low, backup stops at the battery's minimum level. Once the sun is back, solar recharges the battery and backup starts again by itself.

Adding Your Car

There are three terms worth knowing:

• V2L (vehicle-to-load): the car powers things from its charge port. SolaX says many electric cars sold in Australia have it, including several Kia, Hyundai and BYD models, but not all of them do.
• V2H (vehicle-to-home): the car helps power the house. This is what the Binary charger does, using the car's V2L.
• V2G (vehicle-to-grid): the car sends power out to the grid. The Binary doesn't do this. SolaX says it's a further step that Australia's market and rules are still catching up to.

The Binary charges your car from solar or the grid at 1.4 to 22 kW (22 kW needs three phase power). When the house needs power, it takes power from the car's V2L and feeds it, up to 7 kW, into the SolaX inverter, which uses it alongside your solar and battery. You can set times for charging and for giving power back, and SolaX says it supports black start, so the car can back up the house in a blackout.

Before you count on it:

• It needs the X1-VAST or the X3-HYB-G4 PRO. For the X3-ULTRA, SolaX says support is on the way, so ask us whether it's available yet.
• It only helps while the car is home and plugged in, and the car decides how much power it can give.
• SolaX says it works inside the V2L limits your car's maker built in, so it stays within the car's own warranty terms. SolaX still says to check with your car's maker.
• SolaX's documents don't say whether a home battery is required alongside it. A battery covers the hours the car is away.

There's more on our SolaX Binary charger page.

Battery Sizes

The kWh figure is how much energy a battery holds, and the kW figure is how much power it can give at once. A 1 kW appliance running for an hour uses 1 kWh.

SolaX gives usable energy at 90% depth of discharge (how far the battery is run down), and the inverter and its settings decide the final figure. Odd numbers of modules work too, and SolaX lists sizes up to 66.5 kWh across two towers. Every size is on the Clean Energy Council's approved battery list. The full list is on our SolaX HS51 battery page.

The Warranty

• HS51 battery: 10 years from installation, or 129 months from manufacture if that comes first. For everyday solar storage and backup, SolaX promises at least 70% of its energy after 10 years, for up to 6,000 cycles. A cycle is one full charge and discharge.
• X1-VAST, X3-HYB-G4 PRO and X3-ULTRA: 10 years.
• Binary EV charger: 3 years.

SolaX's terms ask for the system to be registered with SolaX once it's commissioned. These are SolaX's terms for products installed in Australia from 1 February 2025.

Rebates

Every HS51 size and all three inverters are on the Clean Energy Council's approved lists, which the federal Cheaper Home Batteries Program requires. Our guide to solar and battery rebates in Queensland explains how the discount works, and we take it off your price on the quote.

What We Check Before We Quote

• Whether your home is single phase or three phase, and what's in your switchboard
• How much power you use, and when, from your bills
• What you want kept on in a blackout
• Where the battery can go under the Australian battery installation standard, AS/NZS 5139
• If you're adding a car, whether it has vehicle-to-load

Then we design the system around your home and give you a written quote, with GST included.