The caravan 12 volt world changed on 18 November 2023, when AS/NZS 3001.2:2022 became enforceable. The part that catches people out is not the standard itself, it is the scope: it applies to alterations made after that date, not only to new vans.
A battery replacement is an alteration. So is adding solar, adding an inverter or relocating a battery. Any of those bring the installation into scope.
None of this is a reason to avoid upgrading a van. Lithium is genuinely better for touring. It is a reason to have the work done by someone who knows the requirements, because a non-compliant installation is a problem at insurance-claim time as well as a safety issue.
What the standard actually splits into
AS/NZS 3001 was divided into two parts. AS/NZS 3001.1 covers the site supply side, the connectable installations that feed power to a van. AS/NZS 3001.2 covers the electrical installation inside the vehicle or relocatable unit itself.
For a caravan, camper trailer or motorhome owner, 3001.2 is the one that matters.
Where a lithium battery is allowed to live
Lithium batteries must not be installed inside the habitable area of the van unless they are separated from it. In practice that means either an external locker, or an enclosure inside the van that is sealed against gas egress, vented to the outside, and accessible only with tools.
A lithium battery sitting under a dinette seat with a hinged lid does not meet that requirement. It is one of the most common non-compliances we find on vans upgraded by a previous owner.
The cells themselves must comply with AS IEC 62619, which is the safety standard for secondary lithium cells and batteries in industrial applications.
Fusing and cable protection
Over-current protection must be fitted on the positive conductor as close as practicable to the battery. The purpose is to protect the cable, not the appliance, so the fuse is sized to the cable rather than to the load.
Extra-low-voltage wiring must be protected against mechanical damage and the environment, must have adequate current-carrying capacity for the load and length, and must be physically separated from any 240 volt wiring in the van.
Solar panels require their own over-current protection, fused on the positive at the panel, using double-insulated cable with an appropriate IP rating for external exposure.
Inverters
An inverter producing 240 volts inside a van must be protected by a separate, labelled residual current device. The RCD status must be visible and accessible without dismantling anything.
This is where a lot of retrofitted inverters fail. A 2,000 watt inverter wired directly into a van’s existing power outlets, without its own RCD and without a changeover arrangement, is both non-compliant and genuinely dangerous.
What this means before you buy
Before committing to a lithium upgrade, it is worth having the existing installation assessed. Often the battery is the cheapest part of the job and the compliance work is the real cost: relocating the battery, upgrading cable, adding correct fusing and sorting the inverter.
Knowing that before you buy the battery is considerably better than discovering it afterwards.