Modular Home Manufacturer Reduces Costs by Right-Sizing its Lithium-ion Batteries for Each Forklift's Power Needs

Summary

A manufacturer of mobile and modular homes sought to convert its forklift fleet to lithium-ion batteries, prioritizing high safety standards and lower total cost of ownership. Initially planning to install large, 80-volt 35.7-53.5 kWh lithium-ion batteries in all sit-down counterbalance forklifts and reach trucks, regardless of application or operating hours, the company engaged EnerSys® for a power study. This study compared the performance and costs of various NexSys® iON lithium-ion battery sizes, ranging from 25.7 kWh to 53.5 kWh. The findings indicated that some forklifts could achieve similar productivity and greater energy efficiency with lower-capacity batteries tailored to their specific needs. Consequently, the company adopted a customized approach to its lithium-ion forklift batteries, projecting savings of $1.5 million by right-sizing rather than standardizing on a single, oversized battery.

Situation

The manufactured home industry has experienced significant growth due to increased demand for affordable housing, with manufactured homes now accounting for one in every nine new homes built in the U.S. A leading manufacturer in this sector, with a network of over 350 home centers nationwide, distributes building supplies to its manufacturing facilities from 50 supply centers. Its fleet of 250 forklift trucks operates one shift daily, six days a week, to move substantial quantities of materials like lumber, hardware, siding, and windows required for building complete houses.

The Challenge

The company decided to transition its forklift equipment from diesel and liquid propane (LPG) to electric power, driven by the enhanced safety of lithium-ion batteries around flammable materials like lumber and their superior environmental sustainability, reducing carbon emissions and waste chemicals associated with combustion engines.

The initial plan was to equip all forklifts with 62.4 kWh lithium-ion batteries, featuring 10-year warranties, to ensure longevity and cost-effectiveness. However, the fleet comprised diverse forklift models, including reach trucks and sit-down counterbalance trucks with capacities of 6,000-lb, 8,000-lb, and 10,000-lb. These forklifts served various functions within the facility, leading to differing power consumption and total operating times. The proposed oversized battery strategy would provide more energy capacity than many forklifts required for their single, six-day-per-week shifts.

Defining Energy Needs

To optimize performance across its forklift fleet, EnerSys® assisted the modular home manufacturer in identifying the actual power requirements for each truck by measuring average energy consumption (amp hours). This process aimed to enhance the fleet's overall energy usage efficiency and cost-effectiveness.

EnerSys® conducted a power study, utilizing typical usage data for each forklift provided by the operation manager at a distribution center, to determine the actual power needs. The company's proprietary EnSite™™ modeling software processed this data, applying application-specific operating parameters and power requirements to evaluate the feasibility of different battery solutions and generate comparative reports on battery and charger sizing and costs.

Solution

Based on the distinct energy demands of each truck, EnerSys® recommended multiple NexSys® iON battery capacities to meet the specific power needs of each forklift at the lowest cost. For instance, the 8,000 lb forklifts were optimally matched with a 44.6 kWh NexSys® iON battery for their single-shift operations. This solution was 35% less costly and required less energy for a full recharge compared to the larger 62.39 kWh NexSys® iON battery.

Furthermore, EnerSys® recommended battery life expectancies aligned with the expected equipment lifespan, thereby preventing unnecessary expenditure on batteries with a longer service life than the equipment itself.

Results

Over time, the modular home manufacturer is transitioning its combustion-powered lifts to right-sized NexSys® iON batteries, leading to reduced emissions and lower energy expenses. All batteries are backed by a 7-year warranty.

By implementing custom-sized NexSys® iON batteries tailored to each forklift application, the manufacturer is avoiding over-investment in the largest battery capacity. This strategic approach is projected to yield savings exceeding $1.5 million over the batteries' lifespan.