Serious Power, Custom Built: Inside a 942Ah Lithium Power System

This isn't your average dual battery setup. It's a purpose-built lithium power system, built in our Garbutt workshop to deliver serious capacity, reliable charging from every source and complete control over how the power is used. Here's what went into it and why each part is there.

01 The storage: 942Ah of lithium

Three ATG 12.8V 314Ah LiFePO4 batteries run in parallel for roughly 942Ah, or about 12kWh, of storage. Lithium holds its voltage under load, weighs a fraction of the equivalent AGM bank and lasts thousands of cycles. That's what lets a system like this run fridges, induction cooktops, coffee machines and air conditioning away from mains power.

02 240V on tap: Victron MultiPlus

The Victron MultiPlus 12/3000/120-50 is an inverter and charger in one. It turns the battery bank into 3000VA of pure sine wave 240V power. Plug into shore power or a generator and it charges the batteries at up to 120A while passing mains power straight through to your appliances.

03 Charging from every source

• Solar. Two Victron SmartSolar MPPT 100/50 controllers let two separate arrays, such as roof and portable panels, charge at up to 50A each.
• Alternator. A Victron Orion XS 12/12 70A DC-DC charger tops up the house bank while you drive, at a controlled rate that suits smart alternators and lithium charge profiles.
• Mains or generator. Handled by the MultiPlus' built-in 120A charger.

04 Monitoring and control

A Victron Cerbo GX ties every Victron component together, with a GX Touch 50 screen showing state of charge, solar input, loads and charging status at a glance. A Victron SmartShunt 500A/50mV measures every amp in and out of the bank, and through Victron's VRM portal the whole system can be checked remotely from anywhere with a signal.

Why settle for an off-the-shelf system when you can have one built around exactly how you use power?

05 Built safe, built to service

A high-current lithium system is only as good as its fusing and wiring. Every circuit is fused to suit its cable size and load, heavy-gauge cable is run and supported properly, and everything is laid out so it can be inspected and serviced down the track. The whole lot sits in a custom welded aluminium enclosure with a proper battery hold-down.

06 The full parts list

07 Who is a system like this for?

• Caravans and motorhomes running 240V appliances and air conditioning off-grid
• 4WD touring setups that need serious capacity for long trips
• Marine applications where reliability and protection matter most
• Off-grid sheds, cabins and work vehicles

Not everyone needs a system this size, and that's the point of a custom build. We size the batteries, solar, charging and inverter to how you actually use power, from weekend touring setups to serious off-grid systems.