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Free Interactive Tool · BATTERY SIZING

Forklift Battery Runtime Calculator

Amp-hours × shift hours × duty cycle.

No sign-upInstant resultsReal Noblelift inventory

Inputs

forklift

Lithium tolerates 80% depth-of-discharge; lead-acid 50%.

Typical: 400–800 Ah for Class I forklifts.

Typical: 50–150 A — varies with lift demand and travel distance.

60%

% of shift the forklift is actively drawing current. Dedicated: 60–70%. Shared: 25–35%.

Results

Runtime per charge

6.7hours

Based on 300 Ah usable (50% DOD) ÷ 45 A effective draw

Recommended capacity

Single 8-hr shift720 Ah
Two 8-hr shifts1440 Ah
For two-shift operation, lead-acid requires a second battery + swap station. Consider upgrading to lithium with opportunity charging.
Shop Forklifts →Shop Lithium Models

About this tool

Battery sizing is the difference between one battery per truck (opportunity-charged lithium) and three batteries per truck (lead-acid with overnight swap stations). Enter your truck's average amp draw, battery capacity in amp-hours, usable discharge depth, and daily shift length — the calculator returns expected runtime, recommended battery pack size for single-shift and multi-shift operation, and a lithium-vs-lead-acid comparison that factors in opportunity charging windows. Most 5,000 lb Class I electric trucks run 5.5-8 hours per lead-acid charge and 8-10 hours per lithium charge.

Shop related equipment

Forklifts
Pallet Jacks
Narrow Aisle

Frequently asked questions

Lead-acid vs lithium — which runs longer?
Neither, in terms of instantaneous runtime — a 48V 600Ah lead-acid and a 48V 500Ah lithium deliver similar peak current. But lithium tolerates deeper discharge (80% vs 50% for lead-acid) and supports opportunity charging, so effective daily runtime on lithium is typically 2× lead-acid in multi-shift operations.
What's duty cycle?
Percentage of the shift the truck is actively drawing current. A dedicated single-job truck might be 60-70% duty cycle; a shared truck at a picking station might be 25-35%. Lower duty cycle = longer runtime per charge.
Why 80% DOD for lithium?
LiFePO4 (lithium iron phosphate) chemistry tolerates 80% depth-of-discharge 3,000+ times. Lead-acid batteries deeply discharged past 50% shed plate material and lose capacity after only 300-500 cycles.
Do I need a battery room for lithium?
No. Lithium batteries don't off-gas hydrogen and don't require ventilation or acid-resistant flooring. Chargers can sit on the warehouse floor next to the truck. This saves 200-400 sq ft of battery room space.
What happens if I undersize the battery?
You'll run out mid-shift. Then either swap a spare (requires battery room + OSHA-certified forklift battery change cert) or do a 15-min opportunity charge on lithium. Chronic undersizing kills lead-acid cells — once a cell drops below 1.75V, it's permanently damaged.

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