Floor scrubber battery runtime calculator
Estimate realistic floor scrubber runtime from battery chemistry, amp-hour rating, voltage and current draw, adjusted for the Peukert effect.
How runtime is estimated
Deep-cycle batteries are rated at the 20-hour rate: the current that would drain them in 20 hours. A scrubber pulls far more than that, and lead-acid batteries deliver less of their rated capacity at high current. This is the Peukert effect. The calculator adjusts for it, then stops at a sensible depth of discharge so it does not plan around destroying your batteries.
runtime (h) = 20 × (Ah ÷ (current × 20))k × usable fraction
| Chemistry | Peukert exponent k (assumed) | Usable fraction (assumed) |
|---|---|---|
| Flooded lead-acid | 1.25 | 80% |
| AGM | 1.15 | 80% |
| Gel | 1.20 | 80% |
| Lithium (LiFePO4) | 1.03 | 90% |
These are typical values, not measurements of any one battery. Real runtime also falls in cold storage areas and as batteries age, and it varies with brush pressure, which can change current draw a lot. See battery runtime data and batteries and charging.
Frequently asked questions
How long does a floor scrubber battery last per charge?
Most walk-behind scrubbers with lead-acid batteries give about 2 to 4 hours of wet scrubbing. Micro scrubbers often run 30 to 90 minutes, and large riders 3 to 5 hours.
Why do I get less runtime than the brochure?
Brochures often quote runtime at low settings with new, fully charged batteries. Heavy down pressure, high vacuum, aging batteries, low temperatures and incomplete charging all cut runtime.
Do lithium batteries run longer?
With the same rated amp-hours, lithium gives more usable runtime because it can be discharged deeper and suffers little Peukert loss. It can also be topped up during breaks.
How do I measure current draw?
Use a DC clamp meter on the main battery cable while the machine scrubs normally with brushes, vacuum and drive running, and take an average over a minute or two.