This case study examines how Midwest Logistics upgraded its Tennant T7AMR floor scrubbers with Surlon Power 48V 210Ah lithium batteries, eliminating the need for daily battery swaps in a 24/5 facility.
Case Details
"The lithium upgrade paid for itself in under 4 months. My team doesn’t dread the battery room anymore. And the floor has never been cleaner – because the scrubbers actually finish their routes now."
— Mark T., Operations Director
The Client: Midwest Logistics (Indiana, USA)
- Facility: 500,000 sq ft distribution center
- Operation Hours: 24/5 (five 24-hour days per week)
- Equipment: 4 ride-on floor scrubbers (Tennant T7AMR)
- Previous Setup: Each machine required two 24V lead-acid batteries (48V total system)
The Challenge: Battery Swaps Were Killing Productivity
Midwest Logistics operated on a multi-shift schedule. Each scrubber required a fresh battery set at shift changes. The traditional lead-acid battery management created severe bottlenecks:
- Inefficient Charging Cycle: Lead-acid batteries demanded an 8-hour charge followed by an 8-hour cool-down period.
- High Equipment Overhead: Required two full battery sets per machine (one operating, one charging/cooling).
- Labor & Safety Risks: Battery swaps took 20 minutes per machine, twice daily, equating to 80 minutes of lost cleaning time. The heavy lifting (requiring 2 people) resulted in two minor back injuries over 18 months.
- Incomplete Cleaning: During the third shift, scrubbers frequently lost power with 2 hours remaining, leaving aisles uncleaned.
The Surlon Power Solution: Single Lithium Pack & Opportunity Charging
To resolve these operational drags, Surlon Power engineered a direct retrofit. We installed a single 48V 210Ah floor scrubber lithium battery into each Tennant machine, permanently replacing the dual lead-acid configuration.
Key Technical Specifications Driving the Upgrade:
- Extended Lifespan: 2,000+ cycles (compared to just 500 for lead-acid).
- Opportunity Charging: 1-hour fast charge capability (0–100%) allows charging during worker breaks, eliminating battery swaps.
- Durability: IP67 waterproof rating ensures no issues with wet floors or accidental spills.
- Smart Integration: CAN bus communication successfully integrated with the scrubber’s display, showing precise runtime remaining.
- Seamless Retrofit: Custom battery tray adapters were fabricated in 5 days, requiring only 2 hours per machine for installation without altering the motor or controller.
The Results: After 6 Months of 24/5 Operation
The transition to Surlon Power lithium technology yielded immediate and measurable improvements across the entire logistics facility.
| Operational Metric |
Before (Lead-Acid) |
After (Surlon Lithium) |
Improvement |
| Daily cleaning time per machine |
14 hours (after downtime) |
16 hours |
+2 hours/day |
| Battery changeovers per day |
2 (40 min total) |
0 |
100% elimination |
| Labor cost for battery handling |
$12,000/year |
$0 |
100% saving |
| Scrubber downtime (dead battery) |
30–45 min/day |
0 |
100% elimination |
Annualized Savings Breakdown (4 Machines):
- Labor for battery swaps: $12,000
- Battery replacements (annualized): $8,400 (Lithium provides a 7-year life vs constant SLA replacement)
- Reduced injury risk (workers’ comp): ~$3,000 (estimated)
- Total Annual Savings = $23,400
Beyond the direct financial savings, the warehouse gained a staggering 730 additional cleaning hours per year (4 machines × 2 extra hours/day × 260 operating days), ensuring a consistently cleaner and safer facility.
Key Takeaway for Facility Managers
For any facility running multiple shifts, a floor scrubber lithium battery eliminates the single biggest operational drag: battery swaps. The return on investment is measured in months, not years, while significantly increasing total cleaning capacity.
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