Best Seller


12V 320Ah LiFePO4

Meet the Roamer 320SMART4 - our 4th generation 320Ah LiFePO4 battery for off-grid vehicles with high energy demands. The integrated Battery Management System (BMS) with Bluetooth provides remote monitoring via the Roamer BMS app and a market-leading discharge rate of 300A (450A peak) lets you run any domestic appliance up to 3600W via an inverter.


In stock

Make 3 payments of £393.33. Klarna. No fees. Learn more
Capacity 320Ah at 12.8V
Up to 300A continuous
Active Balancing
Grade A+ LiFePO4 cells
IP65 waterproof case
Integrated Roamer BMS Bluetooth App
Low temp charge protection
Up to 16 in parallel

Easy 14 day returns

Not entirely satisfied? Send it back within 14 days for a money-back guarantee.

10 year warranty

That’s how much we believe in our product. A decade of powered adventures.

Ongoing support

We’re all about community. Reach out to us any time - we’re here to help.


Up to 3X the power of other lithium battery brands

Our premium LiFePO4 cells provide an exceptional amount of power for their size, delivering a continuous charge/discharge rate of 300A. The state-of-the-art cells also ensure stable voltage throughout the charge and discharge curve and a long lifespan of up to 3500 cycles at 80% depth of discharge.

The upgraded BMS will actively balance all internal cells and supports installation of up to sixteen 320SMART4 batteries in series or parallel - with auto balancing for parallel connected batteries. It provides a complete range of protections including low temperature charging.

High quality power for high-powered adventures

The Roamer 320SMART4 uses the highest quality Grade A+ matched cells and comes assembled with precision-engineered brackets, laser-welded cell connections, flexible copper busbars and an IP65 waterproof case.

Maintaining excellent balance throughout its 15 year life expectancy, your Roamer will deliver stable, high power with every cycle. Our additional factory and warehouse testing processes ensure the highest possible quality and because we believe in our product, we back everything with a 10 year warranty.

To ensure maximum lifespan, every 320SMART4 comes with a state-of-the-art internal Battery Management System (BMS) with Active Balancing - developed specifically for Roamer to support high power off-grid living.

Discover more about our powerful 4th Generation SMART Batteries.

Simple setup

Comprehensive power

Your adventure starts with your setup. And with Roamer, it’s quick and easy. Simply choose your battery location, attach the cables, configure your chargers, and download our Roamer BMS app for real-time monitoring. Uninterrupted power = uninterrupted adventure.

We understand the prospect can be quite overwhelming so if you'd like some support, we offer an off grid electrical system design service. You will spend time with one of our experts who will give you all the tools and advice you need to install your own electrical system, even if you've got no idea where to start. From choosing chargers to cable sizing and configuring settings, we've got you covered.

The power of the Roamer 320SMART4



iPhone charges from start to finish



Laptop charges from start to finish






Days of fridge power



Lord of the Rings viewings on TV



Minutes of hair drying



Hours of air conditioning



Pizzas in the airfryer 

5/5 average rating

“Fantastic service from start to finish and the post sale backup is second to none.”

Rob Landsman

My partner and I have had the pleasure of buying a battery from Roamer. Being new to the campervanning world we sometimes need all the help we can get, and the people at Roamer offer help and advice by the bucket load. Today we received help from the amazing Steve and then had a follow up call from Chris, two of the nicest people you could ever wish to speak to. We can't recommend Roamer highly enough. Their products are very well made and after sales service is second to none.

Rebecca Freear

Having had an A1 buying experience with the guys at Roamer batteries, we were confident to ask for help when needed. Steve spent ages on the phone, patiently going through settings on the charge controller and advising re apps and appliance energy usage. Chris called twice later to make sure we had got the information we needed. If only all companies were as caring and thorough as Roamer Batteries, they are a top class small British business!

Joseph Parker

First and foremost Roamer batteries “do what they say on the tin”. Having purchased batteries before that did not live up to their amp hour claims, this is a brand you can trust. Setting up an off grid system at home to avoid energy price increases was made a good deal easier by all the help and advice. You can always buy cheaper but I am not sure you will ever get better value for money when it comes to buying top quality batteries.

Graeme Kerr

The team at Roamer are fantastic. Seriously, if you are in the market for this type of product I wouldn't recommend another company. After placing our order, Steve and Chris have been nothing short of brilliant in supporting us on delivery updates, schematic design & support, video calls, install advice... the lot. We are relative novices in this area and ask a lot of questions but the team is always there, exactly what you need from this type of purchase.

Indra Åkerblom

We are extremely pleased with the help we got from Steve and the crew at roamer batteries. We needed to upgrade our battery bank and they helped us out. Such a good price for what you get, extraordinary customer service and they really went above and beyond with helping us sort shipping and installing the battery. Would highly recommend it!

Rowan Robinson

Been thinking about going lithium in the van and came across these guys who have some pretty sick branding. Spoke to Chris who answered all my questions and said they could design me a full system to suit my needs along with a battery! The fact that they took their time talking things through with me was the clincher, the customer service was great! Friendly and knowledgeable, I can definitely recommend these guys.

Felix Van Spall

Roamer supplied the electrical design for our self build camper which saved us weeks of research and newbie mistakes, I highly recommend to anyone taking on a self build. Roamer also supplied all the electrical equipment (price matched) with telephone support fo the install - great when you have those little recommendations and questions you're not sure about. Big Fan

Compare models


Change model
Capacity (Ah)
Nominal Voltage (V)
Continuous Discharge
Continuous Power
Charge Temperature
0 to 60C
Dimensions (mm)
522L x 244W x 228H
30 kg
Total Price


Change model
Capacity (Ah)
Nominal Voltage (V)
Continuous Discharge
Continuous Power
Charge Temperature
0 to 60C
Dimensions (mm)
522L x 270W x 228H
38 kg
Total price
For extended tours


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Safety First

Here at Roamer, we take safety extremely seriously and strive to make the safest LiFePO4 batteries possible. It is no secret that Lithium can be dangerous and whilst LiFePo4 is without doubt, the safest option, it is still not without risk.  And that’s why we go above and beyond on both compulsory and voluntary extensive safety tests and processes. We choose to test every single battery before it leaves the factory by cycling to 100% and 0% and applying a high charge and discharge load to identify potentially faulty cells and connections, test BMS performance and verify cell balance at the top and bottom of the voltage-charge cycle. Our batteries use only traceable branded cells from reputable manufacturers with lab test reports to verify battery safety as part of the EN 62619 certification. Finally, our product and fulfilment services also meet the courier requirements to ship Dangerous Goods under the UN3480 guidelines and have CE, UKCA, RED and RoHS certifications. Find out more about the steps we have taken to ensure maximum safety here.

Bluetooth enabled

Less wondering

More wandering

Know your power with the all-new Roamer BMS App - the ultimate wingman for uninterrupted adventure. It’s easy to use, connects via Bluetooth, and lets you track and monitor the status of your battery from the comfort of your van, boat, or home. Real-time feedback at your fingertips.