Freight Class for Batteries
Batteries are dense enough to rate freight class 50 almost every time: a 36-volt forklift battery measures about 208 lb/ft³, and even a 31 lb lithium deep-cycle battery about 68 lb/ft³. The class is the easy part. Lithium batteries are Class 9 hazmat (UN3480 on their own, UN3481 in or with equipment), and forklift batteries are Class 8 wet batteries, each with its own packing rules.
Lithium batteries: which entry applies
The Hazardous Materials Table lists lithium ion batteries shipped on their own as UN3480 and lithium metal batteries as UN3090, both Class 9. Batteries inside equipment, or packed with it, are UN3481 for lithium ion. UN3480 is forbidden on passenger aircraft and limited to 35 kg per package on cargo aircraft, which is one reason large lithium batteries go by truck.
A Battle Born 12-volt, 100 Ah lithium iron phosphate battery is 12.76 × 6.86 × 8.95 inches and weighs 31 lb. At about 1,200 watt-hours, it is far above the small-battery limits, so on its own it ships as fully regulated UN3480, Class 9, with hazmat papers, marks and labels.
Worked examples
Battery sizes and weights come from East Penn's Deka selector guide and Battle Born's product page.
36-volt forklift battery — class 50
Deka 18-D125-13 (East Penn): 37.81 × 15.56 × 30.56 in, 2,169 lb.
37.81 × 15.56 × 30.56 = 17,985 in³ ÷ 1,728 = 10.4 ft³. Density = 2,169 lb ÷ 10.4 ft³.
208 lb/ft³ → class 50. At over 2,000 lb, its pallet unit must carry a 4,000 lb test load.
Lithium deep-cycle battery — class 50
Battle Born BB10012, 12 V 100 Ah: 12.76 × 6.86 × 8.95 in, 31 lb (battery only).
12.76 × 6.86 × 8.95 = 783 in³ ÷ 1,728 = 0.45 ft³. Density = 31 lb ÷ 0.45 ft³.
68 lb/ft³ → class 50, shipped as UN3480, Class 9, because it is well over 100 Wh.
The small-battery exception
Under 49 CFR 173.185(c), lithium ion cells of up to 20 Wh and batteries of up to 100 Wh are spared most of the hazmat paperwork, marking and labeling rules, but each battery must show its watt-hour rating, and the package must carry the lithium battery mark. Packages of excepted batteries on their own are limited to 30 kg (66 lb).
By highway or rail only, those limits rise to 60 Wh per cell and 300 Wh per battery, if the outer package is marked as forbidden on aircraft and vessels. Check the watt-hours printed on the battery before you decide which rules apply.
Forklift batteries
Industrial lead-acid batteries are wet batteries, UN2794, Class 8. They are also very heavy. East Penn lists a 24-volt Deka walkie battery (24¼ × 8 5/16 × 23 3/16 inches) at 464 lb, and a 36-volt reach-truck battery (37 13/16 × 15 9/16 × 30 9/16 inches) at 2,169 lb.
Under 49 CFR 173.159(d), a battery on a pallet must be firmly secured, the unit can be no taller than 1.5 times the pallet's width, and it must carry twice its own weight stacked on top, or 4,000 lb if it weighs more than 2,000 lb. The terminals must be covered with non-conductive caps or tape so they cannot short.
Check a battery shipment
Enter the battery or pallet size and the total weight. The class will almost always be 50; check the hazmat rules for the battery type as well.
Density-based estimate. Some commodities carry a fixed NMFC class — check our freight class by commodity pages.
Estimated Freight Class
Density
54.99
lb/ft³
Volume
53.33
ft³
Weight
2,933
lb
50+ lb/ft³ → Class 50
NMFC density scale (Docket 2025-1, effective July 19, 2025)
Free PDF includes a watermark. Pro removes it & adds your brand.
Estimates only — verify freight class/NMFC and chargeable weight with your carrier.
Uses the 13-tier NMFC density scale (Docket 2025-1). See the full freight class chart.
Frequently asked questions
What freight class are batteries?
Almost always class 50, because they are so dense. A 36-volt forklift battery measures about 208 lb/ft³, and a 12-volt 100 Ah lithium battery about 68 lb/ft³.
Are lithium batteries hazmat for LTL?
Yes. Lithium ion batteries are UN3480 (alone) or UN3481 (in or with equipment), Class 9. Only small cells and batteries, up to 20 Wh and 100 Wh, qualify for the lighter rules in 49 CFR 173.185(c).
What is the 300 Wh rule for lithium batteries?
By highway or rail only, 49 CFR 173.185(c) raises the small-battery limit to 60 Wh per cell and 300 Wh per battery, if the outer package is marked as forbidden on aircraft and vessels.
How heavy is a forklift battery?
East Penn lists a 24-volt Deka walkie battery at 464 lb and a 36-volt reach-truck battery at 2,169 lb to 2,837 lb, depending on capacity.
How do you ship a forklift battery?
As a wet battery, UN2794, Class 8, firmly secured to a pallet. Under 49 CFR 173.159(d), the unit can be no taller than 1.5 times the pallet's width, and the terminals must be protected against short circuits.