DIY Lithium Battery

24-volt 360-amp-hour LiFePO4 batteries

Building our own LiFePO4 Batteries

While there are a lot of lithium batteries on the market, we decide to do it ourselves by assembling sixteen LiFePO4 battery cells into two 24-volt 360-amp-hour batteries. Along with diving deep into subjects such as parallel vs. series connections, bus bars vs. cables, and battery management systems, we also construct our own battery boxes and bus bars. The end result is a unique set of batteries.

Weighing the pros and cons between lead acid and lithium batteries such as wet cell, gel cell, AGM, and LiFePO4 to pick the best camper battery.
Best Camper Battery
Selecting voltage, amperage, & chemistry
We make a custom battery box for our DIY lithium batteries featuring buck riveted aluminum, high impact rubber, and a plexiglass viewing window.
Assembling A Custom Battery
Bringing all the parts together
We make a custom battery box for our DIY lithium batteries featuring buck riveted aluminum, high impact rubber, and a plexiglass viewing window.
Constructing a Battery Box
Selecting voltage, amperage, & chemsitry

RV Batteries 101

What to know when picking a battery

Sourcing batteries for an RV is a balancing act between many different concerns. Price, weight, efficiency, and safety are all major concerns when settling on a power source that will be inside our home on wheels. Fortunately, we’ve broken down these variables and more to decide what batteries make the best power sources for RVs.

3.2V 180Ah LiFePO4 battery cells arranged in parallel
Best Camper Battery
Lead Acid vs. Lithium
Labeling the positive and negative battery cell leads
Choosing a Lithium Battery
Chemistry, voltage, amp-hours, and vendors

Battery Design

Before we can build our battery, we need to settle on how we want that battery to operate. After settling on LiFePO4 batteries for our build, we go ahead and order 16 cells. Why sixteen? We knew we planned to build a fulling electric camper, so we needed a lot of power. But we can’t simply buy a 12-volt cell. We make a 12-volt battery by combining 3.2-volt cells. And sixteen cells gives us a lot of options for arrangements.

Parallel vs. Series

Arranging battery cells to make our ideal battery

We have sixteen 3.2-volt 180-amp-hour LiFePO4 battery cells to power our truck camper.  Depending on how we arrange them, we can have anything between a 3.2-volt to a 48-volt battery.  It’s all a matter of understanding parallel and series connections and how they affect amperage and voltage.

Diagram of battery cells arranged in 8s2p.
Parallel vs. Series
How we arrange our battery cells

Everything Else

There is more to a battery than just cells. While we know how we want to arrange the battery cells, we first need to connect, manage, and protect the cells. For that, we have bus bars, a battery management system (BMS), and a battery box. You don’t need to ask; of course, we made the bus bars and battery box. Check them out!

Bus bars (busbars) are short strips of conductive metal for high current electric connections. Learn how to build DIY bars for lithium battery cells.
Bus Bars
Making Our Own Connections
Connecting to the BMS with an iPhone App
Battery Management System
Guaranteeing battery efficiency & health
We make a custom battery box for our DIY lithium batteries featuring buck riveted aluminum, high impact rubber, and a plexiglass viewing window.
Battery Box
Securing, protecting, and showing off our battery

Assembling The Battery

With all the components together, we are ready to assemble the battery. It took a lot of research and preparation to get here but when the time comes we make quick work of the battery.

A Video Walkthrough

Bringing it all together

After building a custom battery box, crafting bus bars, balancing our battery cells, and prepping the battery management system, assembling our two lithium batteries is delightfully straightforward. Follow along with this satisfying timelapse video.

The Latest From Roam Lab

We are always tweaking our system. See what’s new in our most recent posts.