A warehouse planner has to specify a lithium battery for a fleet of counterbalance trucks. Suppliers ask for voltage and amp-hours, but the planner only knows shifts, hours and the old lead-acid battery label.
Size from energy, not from the old label. Measure kWh used per truck per shift from charger records, add a reserve, then divide by the battery’s nominal voltage to get amp-hours and check the result against the voltage your truck needs. Compare it with real pack sizes, then confirm fit and weight with the supplier. Redway lists 48V forklift packs with nominal energy of about 15.6 kWh (304Ah), 23.6 kWh (460Ah) and 28.7 kWh (560Ah).
Step by step
- Measure energy per shift. Use charger or energy-meter records over a normal fortnight for each truck type, and take the busiest shift, not the average.
- Add a reserve. Allow margin so the pack is not run to empty and can cover a longer day. A sensible reserve is a judgment for your operation; ask the supplier for guidance on depth of discharge.
- Convert to amp-hours. Amp-hours is energy divided by nominal voltage. For a 51.2V pack, 20 kWh is roughly 390 Ah; the exact figure depends on the model.
- Check opportunity charging. If trucks charge in breaks, a smaller pack may be enough. See our opportunity charging article.
- Check fit and weight. Compare outline and weight with the compartment; our measuring guide shows how.
An illustrative example
Suppose a truck uses 17 kWh in its busiest shift and you want a reserve of about 20 percent. Then the target is roughly 21 kWh, which points to a pack in the 400Ah class at 51.2V. This is only an example; use your own measurements.
Redway’s runtime and shift planning page and sizing tools guide give more background.
Checking the result
After choosing a size, run one truck on the new pack for a week and compare actual kWh per shift with your estimate. Adjust the reserve if the truck ends the day with much more or much less charge than expected. Then order the fleet in stages, so the lessons from the first trucks can be applied.
Risk limits
Energy use changes with load, lift height, travel distance, temperature and driver habits, so test on one or two trucks before ordering a fleet. Confirm voltage, current limits and communication with your truck maker. This article is general guidance.
Additional perspectives
Log a full fortnight and mark the heaviest day. Sizing on the heaviest realistic shift avoids running short once volumes rise, and it gives the supplier a number they can check.
Redway Tech Editorial Team – Warehouse planner perspective
Check the truck’s voltage window and controller limits before choosing capacity. A bigger pack does not help if the truck cannot use the extra current or cannot take the extra weight.
Redway Tech Editorial Team – Truck technician perspective
Send the energy figures, shift pattern and charging plan with the truck model. With those I can propose a pack and an expected runtime far faster than from a voltage and amp-hour request alone.
Redway Tech Editorial Team – Supplier engineer perspective
Specifications are taken from Redway product pages as of October 2026. Where a figure isn’t published, this article says so. Confirm current specifications for your model with Redway before ordering. This article is general guidance, not a site-specific engineering assessment.
Related products
- 48V 560Ah 550Ah Forklift Lithium Battery
- 48V 460Ah 450Ah Forklift Lithium Battery
- 48V 300Ah 304Ah Forklift Lithium Battery
- 48V 420Ah 400Ah Forklift Lithium Battery
- 48V 600Ah 630Ah Forklift Lithium Battery
Related topics
- Forklift Battery Runtime & Shift Planning
- Sizing Methods & Load Audits
- Forklift Battery Voltage & Capacity
- High-Capacity Forklift Batteries & Ah Sizing
- Forklift Fast & Opportunity Charging
- Forklift Battery Replacement & Conversion
- Forklift Models, Specifications & Technical Guides
- Forklift Energy Solutions & Electrification
- Lithium vs Lead-Acid Forklift Batteries
- 48V Forklift Battery Systems
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