At 12V, a 400Ah LiFePO4 pack holds about 5120Wh, roughly double a 200Ah. That's the difference between managing your power and simply using it. If your setup is a fridge, lights and the odd charge, 200Ah lithium batteries are the lighter, cheaper step, and 300Ah lithium batteries sit in between for a few days off-grid with occasional inverter use. For narrow bays, also look at slimline lithium batteries, and the wider touring range is in lithium batteries for camping.
Our Range of 400Ah Lithium Batteries
We stock 400Ah lithium batteries from brands trusted on Aussie caravans and off-grid builds:
- Custom Lithium batteries: caravan and NextGen ultra slim cases in 400Ah and 460Ah, plus 24V ultra slim packs, all rated at 380A continuous with a 7-year warranty.
- Amptron batteries: the BluEdge 12V 400Ah, with 300A continuous, Bluetooth, RS485 and CAN Bus in an IP67 case.
- Enerdrive | Dometic batteries: the B-Tec slimline 400Ah, with Bluetooth monitoring and a 216.5mm deep case.
- K2 batteries: a 12V 400Ah pack at 5120Wh with built-in communications.
Who a 400Ah Lithium Battery Suits
- Air con and induction: Big 240V loads through an inverter need both the capacity and the continuous amps to back it up.
- Long stays off-grid: Several days without driving or a sunny spell, with two fridges, Starlink or a diesel heater running.
- Off-grid cabins and sheds: A 24V 400Ah pack holds about 10.2kWh, which starts to look like small home storage.
- One battery, not a bank: A single pack means one BMS and less cabling than wiring smaller batteries together.
What to Look for in a 400Ah Lithium Battery
Weight and mounting
This is a two-person lift. The packs here sit between about 35kg and 60kg. Custom Lithium's 400Ah caravan case is the compact one at 400 x 235 x 260mm and 35kg, while the Enerdrive slimline is around 60kg. Whatever you choose, the floor or frame needs to carry it properly, especially in a canopy on corrugations.
Shape of the bay
A tall, narrow space suits an ultra slim case like Custom Lithium's NextGen, which is 116mm wide across the body. A conventional under-seat box suits the caravan or BluEdge style. Measure length, width and height before you fall for a capacity.
Continuous discharge and charging
Match the inverter to the battery's continuous rating, not the amp-hours. Custom Lithium packs here are rated at 380A and the Amptron BluEdge at 300A. On the charging side, a 400Ah lithium battery wants a decent solar array and a DC-DC or AC charger with a lithium profile and enough current to make a dent in it.
New to lithium? Start with our guide to choosing lithium batteries for camping.
Why Buy 400Ah Lithium Batteries from Outback SafeTrack
- Free Shipping: Orders over $299* ship free Australia-wide.
- Price Match Guarantee: Found them cheaper? We'll match it.
- Speedy Delivery: 2-10 business days, or a $100 gift voucher if we're late.
- 30-Day Easy Returns: No restocking fees on eligible returns.
- Expert Support: We'll help you size the battery, inverter and charging for the way you actually travel.
Ready to Go Big With a 400Ah Lithium Battery?
Browse the 400Ah lithium batteries above and check the case against your bay. Call 1300 902 361 if you want a hand matching the battery to your inverter and charging setup.
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