Your lithium forklift battery is lighter than the lead-acid one: do you need extra counterweight?

Direct answer: Possibly, but only the truck maker can say. In an electric counterbalance truck the battery is part of the counterweight, and a lighter pack can change stability and rated capacity. OSHA requires the truck manufacturer’s approval for modifications that affect capacity and for additional counterweight. Get written approval before ordering.

Why it matters: a lead-acid battery is heavy, and truck designers use that mass to balance the load on the forks. A lithium pack of similar energy weighs less. Redway’s pages list about 65 kg for the 24V 280Ah pack, about 164 kg for the 48V 300Ah pack and about 330 kg for the 36V 700Ah pack. We do not quote lead-acid weights, because they vary by truck and battery. Read them from the truck data plate and the old battery’s label.

The rule: OSHA’s powered industrial truck standard says modifications and additions that affect capacity and safe operation must not be made by the user without the manufacturer’s prior written approval, and that capacity and operation plates must be changed accordingly (29 CFR 1910.178(a)(4)). It also says additional counterweighting of fork trucks shall not be done unless approved by the truck manufacturer (1910.178(q)(6)). OSHA references ANSI B56.1 for the design of new trucks.

Ask the truck maker, in writing: what are the minimum and maximum battery weights for this model; is a lithium pack approved; if ballast is allowed, how much, where and how is it fixed; what happens to rated capacity and stability with the new pack; and what revised data plate will be issued. The answers are specific to the truck model, so this article cannot give a number.

If the pack is too light, the fix is manufacturer-approved ballast or a pack built with added mass, never improvised weights. The Redway pages state that OEM customisation is available but do not publish ballast options, so ask whether a ballasted or steel-cased variant exists for your compartment. Redway cannot approve a change to the truck itself.

After installation, update the nameplate as the approval requires, brief operators (OSHA’s training topics include vehicle stability and charging and recharging of batteries, 1910.178(l)(3)), and test with a real load before returning the truck to service. Keep the approval, the drawing and the nameplate photo on file. For capacity sizing see our post on sizing a lithium forklift battery from lead-acid Ah.