Are Plastic-Cased Lithium Batteries a Genuine Risk in Caravans - Why We Use Metal-Cased LiFePO4

Short answer
Yes, it is a genuine concern. LiFePO4 is inherently safer than other lithium chemistries, but poor-quality packs, incorrect charging, mechanical damage, or enclosure failure can still lead to smoke, fire, or toxic off-gassing. In a confined caravan, any battery event is serious. That is why our SJRV batteries use a metal case and a robust BMS as part of a layered safety approach.

Safety is a System - Chemistry + BMS + Enclosure + Installation

• Safer chemistry - LiFePO4 has a higher thermal runaway threshold than cobalt-rich cells and releases less heat if abused.
• Battery Management System (BMS) - protects against overcharge, over-discharge, over-current, short-circuit, and temperature abuse.
• Enclosure - the case influences heat spread, mechanical protection, and how an incident is contained.
• Installation - correct fusing, cable sizes, ventilation, and secure mounting are non-negotiable.

Why We Prefer Metal-Cased Batteries in Caravans

• Non-combustible shell - metal does not add to the fire load. If something goes wrong, a metal enclosure will not melt and drip onto flooring or soft furnishings.
• Better mechanical protection - resists puncture, deformation, and impact from gear shifting in transit. Protecting cells and the BMS reduces the chance of internal damage.
• Heat spreading - metal conducts heat away from localised hot spots more effectively than plastic, helping the pack remain thermally even under load and charge.
• Event containment - in a worst case, a rigid, sealed metal box can help slow and contain flames or hot ejecta compared with a softened plastic housing. No enclosure is a guarantee, but metal is the safer direction.
• Secure mounting - metal cases accept solid brackets and threaded fasteners, making it easier to meet proper restraint requirements for corrugations and emergency stops.
• Ingress resistance - sealed metal enclosures help keep dust and spray out when installed as specified, reducing the risk of conductive grime or moisture around terminals and electronics.

What a Metal Case Does - And Does Not Do

• Does - improve physical robustness, heat spreading, and incident containment compared with typical plastic boxes.
• Does not - make a battery indestructible or eliminate risk. Abuse, incorrect chargers, damaged cells, or external fires can still cause failure.
• Does - support clean, secure installs with proper brackets, covers, and cable strain relief.
• Does not - replace the need for a quality BMS, correct fusing, or installers following the manufacturer’s instructions.

Plastic-Cased Packs - Where The Risk Comes From

• Melt and drip hazard - elevated heat can soften plastic, exposing internals and spreading burning material.
• Deformation - heavy tie-downs and vibration can distort thin housings, stressing cells or BMS boards.
• Impact vulnerability - puncture or crush resistance is generally lower than a rigid metal shell.

Our Approach - SJRV Metal-Cased LiFePO4

• Metal enclosure - rigid, non-combustible case designed for secure mounting in caravan lockers and battery bays.
• Integrated BMS protections - over-voltage, under-voltage, over-current and temperature monitoring to help prevent misuse events.
• Serviceability and install - clearly marked terminals, straightforward cabling, and proper provisions for strain relief and mounting.
• Warranty and support - backed locally so faults are dealt with promptly. See individual product pages for terms and test information.

Installation Checklist For Caravan Safety

• Fuse placement - main fuse as close as practical to the battery positive. Branch circuits fused to cable/device ratings.
• Cable sizing - size for maximum current and total run length. Keep runs short and use quality lugs with proper crimping.
• Charging profiles - DC-DC, MPPT solar, and mains chargers set to LiFePO4. Avoid charging below manufacturer low-temp limits.
• Ventilation and separation - allow airflow around chargers and inverters. Keep the battery away from heat sources and flammables.
• Secure mounting - rigid brackets to restrain the battery under harsh braking and corrugations.
• Parallel and series - only as the manufacturer allows. Pre-charge to equal voltage before paralleling identical units.
• Regular inspection - check terminals, cables, and mounting after rough tracks. Keep compartments clean and dry.

Brutal Honesty

• No lithium battery is risk-free. LiFePO4 lowers the risk profile, but installation and product quality still decide outcomes.
• Metal-cased batteries are not a magic shield, yet they materially improve protection and containment compared with common plastic boxes.
• If a supplier cannot specify protections, mounting methods, or charger settings, that is a red flag.

Bottom line
If you are fitting a lithium battery in a caravan, choose LiFePO4 chemistry, a proven BMS, and a metal-cased enclosure installed with correct fusing, cable sizes, and ventilation. That combination meaningfully reduces risk and improves reliability on Australian roads.

Browse SJRV metal-cased lithium batteries
General information only - 240V work must be performed by a licensed professional, and all installs should follow the battery and charger manufacturer instructions.