• Paul Kageler

48V LFP Batteries – Good Ownership Experience and Advancing Technology

Updated: Mar 15, 2021

The market for 48V batteries with the stabile lithium iron (ferrous) phosphate cathodes (LFP) is expanding in the USA based on a number of factors including good overall ownership experience, the recent wide spread availability of batteries capable of high discharge rates, greater awareness that LFP batteries do not catch fire, the realization that LFP batteries have a much higher energy density than lead-acid, increased customer assistance when switching from lead-acid batteries, the evolution to higher voltages (48V), larger sizes and more overall customization.

As far as the market history in the USA, LFP 12V batteries became a popular drop-in replacement for 12V deep cycle lead-acid batteries for motorhome & towable recreational vehicles (RVs), residential solar energy storage, marine applications, golf carts, and warehouse equipment such as fork lifts.

During the early stages of market development, the LFP battery cells typically had limited surge power and low energy density as compared to Li-ion NMC batteries. Other restrictive issues included limited market channels, customer concerns about fire hazards, limited customer support, extensive cabling to achieve high capacity & voltage, and higher cost when compared to equivalent lead-acid batteries.

Still, early users of drop-in LFP batteries were pleased with the drastic reduction of battery maintenance, much greater longevity in terms of charge cycles, lighter weight, a more constant voltage output, options to Do-It-Yourself (DIY) assembly of cells into battery packs, and the LFP batteries proved to be very reliable and did not catch on fire during accidents or other abuse!

Based primarily on social media, online marketing, and the rapid advancement of LFP battery cell technology; the demand for low voltage (~12, 24 48, & 72) LFP batteries and battery cells grew quickly and the market/supply chain responded.

Within a specified price bracket, LFP batteries & cells can be custom designed to better meet specific applications. Several parameters that a cell manufacture or battery pack assembly factory can control include energy densities, power discharge rates, expected number of charge cycles, charge times, mechanical strength of key components, etc. As an example, power sports oriented off-road EVs can select lighter weight LFP batteries capable of higher power discharge rates to provide end users with spirited acceleration, enhanced hill climbing ability, and allow for greater top end speeds.

The sourcing channels for LFP batteries and cells is rapidly expanding. This includes golf cart shops that can perform convenient turnkey battery swap outs, online stores, authorized domestic distributors, factory direct sales, and some physical store locations.

Many of the successful online stores are sales & customer service centers for a shop located in the USA that assembles cells into complete batteries ready for shipment and customer installation. The better assembly shops offer domestically enforceable warranties, have good Quality Assurance (QA) and Quality Control (QC) procedures. The combination of best practice domestic battery assembly, user friendly website, good customer call in services, and a strong warranty has contributed to the rapid growth in mail order LFP batteries.

Good customer call in services include a knowledgeable staff that can provide customers with installation instructions including help with ensuring compatibility and optimization of chargers, cabling, connectors, inverters, speed control programing, etc. plus

For the DIY market based on assembling battery cells and Battery Management Systems (BMS) into battery packs, there is a rapidly growing pool of online videos to gain guidance from. With a reasonable amount of research and peer communication, a member of the DIY community can purchase the appropriate LFP battery cells plus auxiliary components and then complete a custom-made battery pack that meets performance expectation and saves money. Good technical and purchasing judgement is needed along with basic craft skills for executing a successful DIY project.

Some Original Equipment Manufacturer (OEM) golf cart companies are now offering standard golf carts, rough terrain golf carts, shuttle carts, and light duty Utility Task Vehicles (UTV) with LFP battery packs over a wide range of sizes. One advantage of buying an OEM cart is the entire power train is designed to optimize the use of the LFP battery.

Golf carts in the USA are limited to 25 MPH top speed. This means for golf carts repurposed for exclusive off-road and/or private road use may require reprogramming of the speed controller and other component modifications to achieve speeds greater than 25 MPH.

Below is a comparison table for ~ 48V LFP battery or battery kits suited for quickly increasing the range and in some cases the power output of golf carts and other types of electric carts.

For OEM carts sold in the USA the beneficial competition between Li-ion NCM and LFP batteries will continue. For many off-road carts, street legal EVs, solar energy storage systems, back up batteries, RVs, marine vehicles, utility and specialty vehicles, etc. Li-ion NMC or LFP are good options performance wise, so the choice is frequently based on cost, the availability of specialty cells in lower volumes, and/or safety considerations related to the application.

Unlike some street legal EVs designed for longer ranges, short to moderate ranges of up to 90 miles are well suited for most off-road carts. Off-road carts are vulnerable to physical damage while traveling over rough terrain or when loaded onto trailers. LFP batteries capable of high discharge rates are a good fit for off-road electric carts in regards to cost, off-road performance, and have an excellent safety record.

The safety advantage for LFP batteries is well established by laboratory testing and by safety record. Cost can depend on the region, volume of battery cells purchased, and if customization of the cells is highly desirable. The LFP battery cells do no require buying nickel or cobalt which is a significant cost advantage. Another key advantage for purchasing LFP battery cells is that there are several established manufactures that are willing to make batches of customized cells for niche markets.

The higher energy densities, diversity of battery cell manufactures, and location of high-volume factories in 5 different regions are advantages for purchasing Li-ion NCM battery cells. Higher volume OEM may choose Li-ion battery cells supplied from a factory located in the same region.

Another consideration in the procurement of higher performance battery cells is that some vertically integrated EV suppliers do not offer their proprietary Li-ion NCM or LFP cells on the open market. Tesla and BYD are examples of top tier vertically integrated EV manufactures that do not actively pursue outside sales of components such as batteries or cells.

The potential future size of the low to medium range EV market powered by 48V to 72V lithium batteries is considerable. Some examples of EVs that fall into this market segment are golf carts, personal transport vehicles, utility vehicles, low speed vehicles (LSV), Automated Guided Vehicles (AGV), and power sports recreational vehicles. The utility vehicle category includes All Terrain Vehicles (ATV), Utility Task Vehicles (UTV), construction equipment, yard maintenance equipment such as electric riding lawn mowers, and farm/ranch equipment. Examples of power sports vehicles includes high performance carts, snow mobiles, and jet skis.

An important point for the industry is to continue making safety a high priority for LFP batteries, even thou these batteries have a lower risk cathode chemistry. Recognized hazards include potential battery fires caused by manufacturing flaws, improper charging, or physical damage. Many LFP battery cell manufactures use standard nail penetration and crush test to verify a high degree of safety. Extra layers of engineering safeguards frequently utilized include pressure relief device on battery cells and the use of best available ceramic separators.

My experience with 48V LFP batteries is focused on applications in the USA that I am familiar with. Many regions, including developing countries, can benefit from quickly transitioning from small ICE power systems to low noise environmentally friendly electric power systems that utilize 48V or 72V batteries. The LFP cathode chemistry offers low cost, excellent safety, simplicity, and continuing advancement of battery cell technology.

About Author:

Paul Kageler: My broad background includes experience in the global chemical industry, industrial construction, global oil & gas assignments, electrification & solar energy advisor. Job roles while at BASF Chemicals include research & development, project management, plant startup, plant manager, product stewardship manager, and product manage. Job titles at Halliburton include fluid engineer, Sr. Technical Professional, and Global Field Advisor. Also experience in technical sales. I have followed the solar industry since 2010 and developed an interest in Li-ion battery applications. Recent work and studies include residential and remote area solar plus ESS and converting electric off-road vehicles to LFP batteries. My interest during leisure time includes fishing, exercising, and following developments related to Li-ion battery applications. Education: BS Degree in Chemistry from Texas State University

Email: kageler.corp@gmail.com

LinkedIn: https://www.linkedin.com/in/paul-kageler-71525530/

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