The average human life expectancy in the U.S. is about 687,000 hours. That number is accurate, but it is also completely useless for estimating your individual lifetime.
Car makers don’t warrant engines in years of ownership; they warrant them in miles, because a delivery van and a leisure car can be the same age and in a very different state.
Yet walk the aisles of a material handling trade show and you’ll hear the useful life of lithium-ion forklift batteries quoted in hours of operation. Some manufacturers advertise “20,000 hours or 10 years, whichever comes first.” Others promise “8 years of 12,000 hours.”
Meanwhile, the engineering datasheets from serious lithium battery suppliers say something different: 4,000 cycles at 70% depth of discharge. Cycles, because that’s the unit a battery actually keeps count of and understands.
To be fair, even a Li-ion cycle rating is a laboratory number, measured at a controlled temperature, a set charge rate and a defined depth of discharge. But at least it’s the right unit, stated with its conditions. A promise of battery hours is a lab number multiplied by assumptions nobody cares to explain.
A lithium battery ages by the cycle, not by the clock
Every charge-discharge cycle takes a small, measurable toll on a lithium-ion cell. Run the same truck through the same 2,000 hours a year in two different operations and the batteries will age at completely different rates.
Why? Because intensity defines how fast each hour drains the battery.
Heavy work burns more energy per hour
Heavier loads, higher lift heights and attachments like paper clamps or push-pull all require more amp-hours out of the battery pack. The battery depletes faster, cycles more often and ages sooner in the same number of clock hours.
Cold decreases capacity
In freezer and cold-dock applications, extra energy is used for heating the battery or, without heating, usable capacity shrinks significantly. Either way, you charge the battery more often per shift.
Higher Ah capacity stretches cycles
A bigger battery discharges more slowly. A 600 Ah pack doing the same job as a 400 Ah pack accumulates fewer cycles per year and lasts proportionally longer.
None of this shows up in a promise measured in hours. An hours number silently assumes one “average” duty cycle and never tells you which one.
The honest math is simple
A note on units first: some battery manufacturers describe energy draw in watt-hours (Wh) rather than amp-hours (Ah). We’ll use Ah for simplicity, because the voltage is fixed by your truck: you can’t buy a higher-voltage battery to get more power and energy. Your only variable is Ah capacity.
Your energy use per hour can be expressed in amp-hours and your truck manufacturer has already defined it. If the recommended 600 Ah battery is sized to last one 6-hour shift — a typical spec — the truck draws about 100 Ah per hour. In real-life use, a Class I counterbalance truck draws about 90-120 Ah per hour. That’s your consumption rate — or better, get the real-life number from a power study of your truck in your facility.
Below is an example of a mid-size distribution warehouse that runs a 36V counterbalance truck 2,657 hours a year. The truck specification says it draws 100 Ah per hour and its lithium battery is 600 Ah with a warranty for 4,000 cycles.
Four lines of arithmetic tell you everything:
| Step | Calculation | Result |
| Annual energy throughput | 2,657 hrs × 100 Ah/hr | 265,700 Ah/year |
| Cycles per year | 265,700 ÷ 600 Ah | ~443 cycles/year |
| Life expectancy (in cycles) | 4,000 cycles ÷ 443 | ~9 years |
| Life expectancy In hours (in this case only) | 9 yrs × 2,657 hours | ~24,000 hours |
The battery in this operation would beat a “20,000-hour” marketing promise by 20%. But move the same lithium-ion battery to a cold-storage operation and add a clamp attachment to draw 120 Ah per hour and the math collapses to 20,000 hours, under the same 4,000-cycle rating. The cycle number never changed. The hours never meant anything.
Ask for the number the battery understands
Lithium battery cycle life is measured in cycles, full stop. Hours are not a specification; they’re a calculation and it’s only honest when it’s built on your numbers, not the vendor’s assumptions.
So when a supplier promises you hours, ask four questions instead: how many cycles and at what temperature were they measured? At what depth of discharge? At what charge rate? And what counts as end of life — 80% capacity remaining or 70%? Each answer moves the real number; a supplier who can answer them clearly is quoting a specification and one who repeats the headline figure is quoting a billboard.
Industrial Battery Lifetime Calculator is based on this simple formula:
Life (years) = Warranted Cycles / (Hours per Year × Energy Use per hour (Ah) / Battery Ah Capacity)
If a vendor can’t show you that math, they’re not selling you a battery life. They’re selling you a warranty. The best advice to get a real answer for your fleet is to request a power study as part of the deal.
In March 2026, Eneroc USA officially launched U.S. operations, bringing its advanced motive power technology to North America. Founded in 2018 and headquartered in Hangzhou, China, Eneroc is a provider of lithium battery solutions for off-highway and industrial electric vehicles.
