The transition from lead-acid to lithium-ion batteries in counterbalance forklifts is fundamentally altering the physics of the truck's chassis, and tire manufacturers are struggling to keep up. A standard lead-acid battery is a massive, dense block of lead sitting low in the chassis; it acts as a massive, dampening spring absorber for the drive axle.
Lithium-ion batteries are significantly lighter and more compact for the same kWh output. To maintain the truck's rated capacity and stability, forklift OEMs must add solid cast-iron counterweights to the rear of the truck. This completely changes the center of gravity and the dynamic shock loading on the drive tires. The heavy, rigid cast iron doesn't absorb vibration; it transmits it directly into the rubber.
When a lithium-equipped forklift crosses an expansion joint or a dock plate at speed, the impact load is sharp and violent. Standard cushion tires-formulated for the dampened weight of a lead-acid battery-are experiencing severe "chunking," where large pieces of rubber shear off the tread face, and rapid sidewall cracking. Tire manufacturers are being forced to reformulate their rubber compounds, adding more natural rubber and harder carbon blacks specifically for "Li-ion compatible" tires. If a facility swaps a lead-acid battery for a lithium pack without verifying tire conformity, they will destroy their drive tires in a matter of months.
