Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery
This is an estimate only. Actual delivery times can vary with stock availability, courier delays, weather, public holidays and your location.
Enormous Power In A Small Package - The Custom Lithium 620Ah NextGen Ultra Slim Battery Delivers
Running out of space but still need serious juice? This next-gen 620Ah Ultra Slim Lithium Battery has some serious guts. It's an absolute ripper for utes, canopies, and tight installs where every millimetre counts. Don’t let the slim profile fool you, these batteries packs a punch, with enough grunt to run fridges, lights, and even a decent inverter without breaking a sweat. Built tough, built smart, and built right here in Oz.
Grab the Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery today and enjoy serious power wherever the road takes you!
Get the biggest slimline we make and add one to your cart today.

Why The Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery May Be Right For You:
- Don't stress about your battery whilst you're driving through those bumpy outback roads. Safety is Custom Lithium's number 1 priority. The 620Ah Ultra Slim Lithium Battery is integrated with A-grade automotive LiFePO4 lithium cells meaning you can rest assured that your battery will be fine, even if your tires are getting a working over.
- Big bulky batteries are a thing of the past, ultra slim batteries are gaining in popularity, and for good reason! The sleek design of Custom Lithium's Ultra Slim batteries allows them to fit into your caravan, 4x4s and boats seamlessly. Light, slim but powerful, the ultra slim battery is a great alternative for when you're short on space.
- Worried about your battery sliding all over the place? Worry no more as mounting Side Rails are included in this package. Simply mount your new ultra slim battery inside of your caravan, 4-wheel drive or boat to keep your battery intact.
- Great for powering your Star link connections, 240V inverters, your fridges, induction cookers, air compressions, computers, cameras, lights and much more.
- Custom Lithium stand by their products because they know that they are of high quality. That's why each purchase of one of their batteries comes with a 7 year warranty! Every single battery is individually bench-tested, so you know that you're getting a quality product.
- Your battery ain't taking a battering. All components of the battery are insulated against vibration meaning those bumpy roads won't damage your battery.
- Worry less about overheating and short-circuiting. Custom Lithium Batteries are equipped with BMS protection to ensure that your battery maintains performance throughout your journey.
- You're supporting the local economy by buying local. All Custom Lithium Batteries are made here in Australia.
Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery Installation:
If you are unsure about installation, please contact us on 1300 902 361 for assistance, or alternatively please reach out for us to organise an installation.
*Improper installation will void your warranty and may result in injury.

Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery Tech Specs
Custom Lithium 620Ah NextGen Ultra Slim Lithium Battery FAQs
1. Does the Custom Lithium 620Ah Ultra Slim Battery require assembly?
No major assembly is required. The battery comes ready for installation, but it should be securely mounted and correctly connected using suitable cabling, fuses and charging equipment. For high-capacity lithium systems, professional installation by a qualified technician is recommended.
2. What can the 620Ah Ultra Slim Lithium Battery be used for?
The 620Ah battery is designed for high-capacity 12V power systems and is suitable for caravans, camper trailers, motorhomes, 4WD touring setups and off-grid applications. Its slim design makes it particularly useful where installation space is limited.
3. What safety precautions should I follow when using the battery?
Secure the battery properly and use correctly rated cables, fuses and lithium-compatible charging equipment. Avoid short-circuiting the terminals, physical damage and operating the battery outside the manufacturer's specified conditions. The integrated battery management system (BMS) also provides protection for the lithium cells.
4. What warranty does the Custom Lithium 620Ah battery include?
The battery is backed by a 7-year warranty from Custom Lithium. Warranty coverage is subject to the manufacturer's terms and conditions, so the battery should always be installed, charged and operated according to Custom Lithium's requirements.