Modular Home Manufacturer Reduces Costs by Right-Sizing Lithium-Ion Batteries for Forklift Fleet

Overview

A manufacturer of modular homes sought to convert its forklift fleet to lithium-ion battery power to meet stringent safety standards and achieve lower total cost of ownership. The manufacturer planned to install large 80-volt, 35.7-53.5 kWh lithium-ion batteries in all its seated counterbalanced forklifts and reach trucks, regardless of application or total operating hours. EnerSys® conducted a performance study to compare the performance and costs of several NexSys® iON lithium-ion batteries in various sizes, from 25.7 kWh to 53.5 kWh. The study revealed that some forklifts would be equally productive and more energy-efficient when powered by NexSys® iON batteries sized for their specific applications, at a lower cost. The company has adopted a more customized approach to its forklift lithium-ion batteries, anticipating savings of $1.5 million by right-sizing batteries instead of using a single, oversized lithium-ion battery as standard.

Situation

As people seek more affordable housing, the manufactured housing industry has grown steadily. In fact, one in nine new homes in the USA is a manufactured home. One of the leading manufacturers of mobile and modular homes has built many of these new houses, and demand has helped the company expand from one facility to over 350 housing centers nationwide. The modular home manufacturer distributes building materials to its manufacturing plants from 50 distribution centers. During one shift, six days a week, a fleet of 250 forklifts continuously moves tons of lumber, hardware, siding, windows, doors, and all other materials needed to build complete homes.

Challenge

The company decided to convert its forklift equipment from diesel and propane (LPG) to electric power with lithium-ion batteries, as batteries are safer when flammable materials like wood are nearby. Battery power also provides a more sustainable environment, as carbon emissions are reduced and waste chemicals from combustion-powered equipment are eliminated. Initially, the manufacturer planned to switch to 62.4 kWh lithium-ion batteries with a 10-year warranty to ensure longevity and lower lifetime costs. However, the fleet consisted of various forklift models, including reach trucks and 6,000, 8,000, and 10,000-pound seated counterbalanced forklifts. The forklifts were used for different applications throughout the facility, so their actual power consumption and total operating time varied significantly. Their oversized batteries would have considerably more energy capacity than many of their forklifts require for a single shift, six days a week.

Define Energy Needs

To identify the ideal lithium-ion batteries that would optimize performance for its entire forklift fleet, EnerSys® helped the modular home manufacturer identify its actual energy needs for all trucks by measuring average energy consumption (amp-hours). This would help optimize the fleet's energy usage for efficiency and cost. To identify the actual energy needs, EnerSys® conducted a study using typical usage data for each forklift, provided by the operations manager at a distribution center. EnerSys® processed the energy study data using its proprietary EnSite™ modeling software. The software uses application-specific operating parameters and power requirements to assess the feasibility of battery solutions and generate reports comparing batteries and chargers in terms of size and cost.

Solution

Based on each truck's unique energy needs, EnerSys® recommended various NexSys® iON battery capacities for each individual forklift, meeting specific power requirements at the lowest cost. For example, the 8,000-pound (3,629 kg) forklifts were best matched with the 44.6 kWh capacity NexSys® iON battery for one of its single-shift applications. This battery is 35% less expensive and requires less energy to fully charge than the largest NexSys® iON battery at 62.39 kWh. EnerSys® also recommended a projected lifespan in line with the equipment's expected service life. This avoided unnecessary costs associated with purchasing overly expensive batteries that would outlast the equipment they powered.

Results

For several years, the modular home manufacturer has been converting its forklift fleet from internal combustion to NexSys® iON battery power, reducing emissions and energy costs. All batteries come with a seven-year warranty. By using customized NexSys® iON batteries for each forklift application, the manufacturer avoids overspending on the largest battery, with an estimated savings of more than $1.5 million over the batteries' lifetime.

Overview of Performance Study Data