Electric Skid Steer Conversion

Overview: Why Convert a Skid Steer to Electric?

A skid steer is a compact loader that steers by varying the speed of wheels on each side rather than turning the front axle. These machines have become workhorses on farms, construction sites, and industrial facilities since the 1970s. If you own a diesel-powered unit from the 1990s to 2010s—think a JCB Robot 165, Bobcat S570, or Thomas 153—you might be weighing whether an electric skid steer conversion makes sense in 2026.

The core benefits are compelling: zero emissions at the tailpipe, dramatically lower noise for indoor or sensitive-area work, and fuel and maintenance cost savings that can reach 50% compared to diesel equivalents. Tightening emissions regulations, rising diesel prices, and proven ROI from commercial electric equipment are pushing more owners to consider this path.

This article focuses on converting an existing diesel machine (roughly 40–50 hp class) to an electric powerplant that drives the existing hydraulic system. You’ll find real-world power numbers in gpm and psi, component examples from manufacturers like Curtis, HPEVS, and NetGain, and practical layout ideas rather than generic advice. The roadmap covers assessing your machine, sizing the electric drive, designing the battery pack, integrating hydraulics, and learning from completed projects.

Assessing Your Skid Steer for Electric Conversion

Before you visit eBay for motors or contact a battery supplier, start from what your machine actually needs hydraulically—not from motor peak hp claims that rarely match continuous duty requirements.

Common donor machines include:

• JCB Robot 165 (circa 2001, 44 hp diesel, single or tandem gear pump)
• Bobcat 753, 763, or S570 (40–50 hp diesels)
• Thomas 153 or SL series from the 1980s–2000s
• Mini units like the Ditch Witch SK500

Gather factory specs from manuals or site gauges: hydraulic flow (typically 14–18 gpm), system relief pressure (2600–3000 psi), auxiliary hydraulics (often 5–10 gpm extra), and rated operating capacity. To estimate mechanical hp at the pump, use this formula: hydraulic hp = (gpm × psi) / 1714. For example, 14.5 gpm at 2650 psi yields approximately 27 hp at the pump. However, once you factor in 85–90% pump efficiency and 90% motor/controller efficiency, you’ll need 40–45 hp electric input to match a 44 hp diesel under continuous load.

Check physical constraints: engine bay dimensions (often 24–30 inches wide by 36–48 inches long on 2000–2005 class machines), battery box access behind the cab or under seats, counterweight volume in the rear frame, and cooling paths. Inspect whether your machine runs a single gear pump or tandem/triple arrangements common on JCB Robots and older Bobcats—this directly impacts motor torque requirements at 1800–2500 rpm pump speeds.

Before buying any electric components, document: hydraulic flow and pressure, engine bay measurements, pump mount type (SAE A or B), duty cycle expectations, and auxiliary circuit demands.

Defining Project Goals, Budget, and Run Time

Your project goals shape every subsequent decision. Light farm chores or indoor material handling might need only 45–60 minutes of hard use, while full-shift commercial construction demands 4–6 hours of mixed operation.

Define target run time in concrete terms based on your actual work patterns. A 20 kWh pack delivers roughly 1 hour of heavy digging at 20–25 kW average draw. If you need multi-hour operation, plan for 40+ kWh capacity.

Budget ranges vary widely:

• Low-end builds ($10,000–20,000): Salvaged forklift DC motors, used BMW i3 modules
• Mid-range builds ($25,000–40,000): Quality used components, basic BMS systems
• Premium builds ($40,000–60,000): New HPEVS AC motors, automotive-grade Li-ion batteries, Sevcon controllers

Consider your charging strategy early. Overnight Level 2 charging at 240V suits farm shops, while contractors might need swappable packs or opportunity fast-charging—similar in concept to Moog’s ZQuip modular approach for construction equipment.

The trade-off triangle is real: battery capacity versus machine weight versus project cost. Li-ion at 100–150 Wh/kg beats lead-acid’s 30–50 Wh/kg on density, but the heavier lead-acid can double as useful counterweight. Just ensure weight distribution doesn’t risk tip-over.

Choosing the Electric Motor and Controller

The electric motor replaces the diesel engine as the prime mover for the hydraulic pump. For this application, continuous power and torque matter far more than peak ratings that last only seconds.

Translate hydraulic needs into motor power: our earlier example of 14.5 gpm at 2650 psi requires about 27 hp at the pump, but accounting for efficiency losses, you’ll need approximately 40–45 hp (30–35 kW) electric for full performance.

AC vs DC motor choices:

Tipo di motore	Examples	Pros	Cons
AC Induction/PM	HPEVS AC50/AC51 (30–50 kW at 96V)	Higher efficiency, better continuous ratings	Higher cost, complex controller
Series DC	NetGain WarP 9, ME1004	Lower cost, simpler	Peak power fades at high rpm

A common mistake is looking at a 48V Curtis AC-9 and seeing its 27 hp peak rating. The problem? Its continuous output at 6000 rpm is only about 10 hp—insufficient for a full-size loader’s main pump in continuous duty.

Bumping system voltage to 72–96V enables higher continuous hp at lower current. Common controller families include Curtis 1238/1239 for AC motors and 1231C for DC, with realistic continuous current expectations of 200–250A versus 600A peak. The Sevcon line offers similar capabilities with configurable I/O.

Peak ratings (often 2x continuous) derate quickly under thermal stress. Plan for continuous operation, not burst performance.

For machine sizing: small mini loaders might use a 15–20 kW motor, while mid-size machines like a JCB Robot 165 typically need 30–40 kW continuous capability.

Mounting the Motor to the Hydraulic Pump

The mechanical interface between motor and pump determines reliability. Standard SAE pump mounts (SAE A or B) with splined couplings allow motors like an HPEVS AC50 or NetGain WarP 9 to directly drive the original gear pump.

Alignment is critical. Use concentric mounting plates and flexible couplers to absorb minor misalignment, keeping shaft runout under 0.010 inches TIR and overhang within pump manufacturer limits. Some conversions retain an OEM tandem pump stack on one motor, while others split functions—one motor/pump for drive and another for boom and auxiliary hydraulics.

A practical example: a 2001 JCB Robot 165 conversion might run a single 35 kW HPEVS motor driving the original tandem pump, delivering full hydraulic flow for both drive and implement circuits.

Controller Tuning and Drive Feel

Controller tuning makes or breaks the operating experience. Skid steers require smooth low-speed operation, quick but controllable response for direction changes, and stable pressure for hydraulics.

Modern controllers like Curtis and Sevcon units offer configurable I/O for mapping joysticks to torque or speed demand. Key tuning parameters include:

• Ramp rates (1–5 seconds to full torque)
• Torque limits to prevent stalls
• Minimum rpm settings (1500+) to avoid pump cavitation
• Regenerative braking if adapting drive motors

Use the datalogger function in 2026-era controllers to track current draw, temperatures, and voltage over several days of work, then refine parameters for your specific duty cycle.

Battery Pack Design: Voltage, Capacity, and Layout

The battery pack determines run time, performance, and a significant portion of project cost. It must match your motor/controller voltage.

Common pack voltages:

• 48V: Small or legacy builds, simpler systems
• 72–96V: Serious duty, reduced current and cable sizing
• Higher voltage: Reduced losses, but more complex safety requirements

A 48V example: salvaged BMW i3 12-cell modules reconfigured to approximately 41.6V nominal and 20 kWh total capacity. This provides about 1 hour of heavy work on a mid-size loader drawing 20–25 kW average.

For higher capacity, a 30–40 kWh pack using Nissan Leaf or Tesla modules at 96V targets 2–3 hours of mixed-duty operation. The pack weight (600–800 lbs) doubles as useful counterweight, improving machine stability.

Energy calculation example: Continuous digging at 200–300A on 96V yields roughly 20–25 kWh consumption per hour. Oversize your pack 20–30% for safety margins and battery life preservation.

Physical layout typically places battery boxes under the seat or in the rear frame, with structural mounting serving as counterweight. Design enclosures for IP67 protection against mud, rock chips, and washdowns, with access panels for service.

BMS, Safety, and Monitoring

A Battery Management System handles cell-level voltage measurement, pack current monitoring, temperature sensing, and contactor control. For 2026 conversions, modular BMS units designed for EV modules beat manual balancing approaches in both safety and reliability.

Essential safety features include:

• Pre-charge circuits to protect contactors
• Main contactors with crash/rollover disconnect
• Interlocks tied to seat switches and service doors
• Fusing on each string
• Clear labeling for fire safety and first responders

Install a small dash display showing state of charge, pack voltage, current, and estimated run time remaining. This mimics what commercial electric loaders like Firstgreen’s units provide and helps operators manage their workday efficiently.

Charging Strategy and Infrastructure

Typical charging methods in 2026 include:

Metodo	Power Level	Use Case
120V Level 1	1.4 kW	Emergency backup only
240V Level 2	6–10 kW	Overnight farm/shop charging
DC Fast Charge	25–50 kW	Fleet operations, opportunity charging

A 20 kWh pack at 6 kW charges from 10% to 90% in approximately 4 hours. A 40 kWh pack at 9 kW achieves similar timing. For job sites, J1772 inlets with dust caps work well; shops might prefer hardwired connectors.

Opportunity charging during lunch breaks extends operation for contractors, while scheduled overnight charging suits farm and municipal operations perfectly.

Hydraulic System Integration and Layout

Most DIY electric conversions keep the existing hydraulic architecture—drive motors, cylinders, and valves—intact, changing only the prime mover. This approach simplifies the project while preserving the machine’s proven hydraulics.

Fixed-displacement gear pumps deliver flow proportional to motor speed. Maintaining minimum rpm (typically 1500+) prevents cavitation while allowing variable flow via motor speed control. Think of the throttle response as directly controlling hydraulic flow.

When the OEM machine has multiple pumps, you can either retain a single multi-section pump on one large motor or separate into two smaller motor/pump groups—one for travel, one for lift and auxiliary functions. The parallel approach adds complexity but provides redundancy.

Before conversion, measure real operating pressures and flows using gauges on the donor machine. Brochure specs from 2000–2010 often underrate actual peaks. Size hoses and fittings to match or exceed OEM ratings, typically 1-inch minimum ID for 20+ gpm systems.

Efficiency, Losses, and Power Calculations

Combined system efficiency typically reaches only 60–70% from electric motor shaft to hydraulic work. Here’s the math:

• Pump volumetric efficiency: 85–90%
• Pump mechanical efficiency: ~90%
• Motor/controller efficiency: ~90%
• Combined hydraulic efficiency: ~64%

Our 27 hp at the pump example requires approximately 42–45 hp electrical to match a 44 hp diesel under continuous load. Focusing only on nameplate diesel hp versus motor peak kW is misleading—continuous hp and torque at typical pump rpm (1800–2500 rpm) matter more.

For operators who mostly do light fork or bucket work, slightly undersizing from OEM diesel ratings can still offer acceptable performance with much better controllability and efficiency.

Cooling and Thermal Management

Sustained 200–300A draw generates significant heat in the motor, controller, and batteries, especially during summer construction work. Practical cooling strategies include:

• Repurpose the original radiator fan shroud to move air across heatsinks
• Add 12V electric fans with dedicated ducting
• Consider liquid-cooled motors/controllers on premium builds
• Use glycol loops with compact radiators similar to transmission coolers

Set up temperature sensors and controller derate logic to prevent thermal shutdowns mid-job. Test cooling performance after the first 30–60 minutes of heavy use and adjust as needed.

Real-World Electric Skid Steer Conversion Examples

Real projects demonstrate what power levels, pack sizes, and run times are achievable, giving readers confidence in planning their own builds.

A historical example: a 1980s Thomas skid steer upgraded with a NetGain WarP 9 and Curtis 350A controller managed approximately 30 minutes of hard use on a relatively small pack. While limited, this early conversion proved the concept.

A mid-2010s Bobcat S570 conversion using an HPEVS AC50-class motor at 96V achieved 1.5–3 hours run time depending on workload, with a 30–40 kWh pack capacity. This machine handled mixed farm duties effectively.

Commercial benchmarks provide useful reference points. Firstgreen’s Elise 900 heavy-duty electric loader—sold in North America since the early 2020s—achieves near-silent operation with “full-day” run time in most applications. The company reports operating costs up to 10 times lower than diesel and payback periods around 18 months for intensive users. Last year, several municipal operations in Canada adopted similar machines for indoor waste handling.

Modular electrification systems like Moog’s ZQuip approach—swappable energy modules sized per machine and job—offer inspiration for builders considering removable or expandable battery packs. This idea makes sense for contractors needing quick turnaround without extended charging downtime.

Mini and Niche Machine Conversions

Smaller machines like the Ditch Witch SK500 mini skid steer present excellent conversion opportunities. These units have tandem pumps and loud gasoline engines that practically beg for electrification. Their narrow footprint fits through standard doorways, making indoor operation practical.

Mini conversions typically require:

• Lower-power motors (10–20 kW continuous)
• Smaller packs (10–15 kWh)
• Runtime of 45–90 minutes of useful work

Builders often adapt forklift battery packs or repurpose Tesla/Leaf modules to power standalone electric hydraulic power units on trenchers, small loaders, or even Zamboni-style ice resurfacers. Consider these niche builds as lower-risk testbeds before tackling a primary full-size loader conversion.

Planning, Legal, and Community Considerations

Proper planning prevents expensive mistakes. Document the original machine thoroughly, sketch high-voltage and hydraulic layouts, and schedule realistic downtime for the conversion. A simple plan with clear milestones keeps projects on track.

Regulatory and safety considerations in 2026 include workplace safety rules for high-voltage equipment, lockout/tagout procedures, and maintaining or updating ROPS/FOPS labels and manuals. Once you replace the diesel engine, the manufacturer warranty becomes void, so keep detailed records of modifications and component ratings for insurance purposes. Some insurers require notification of significant machine modifications.

Engage with online communities sharing skid steer, excavator, and similar electric conversion projects. These forums provide practical guidance that no manual covers. However, respect intellectual property—don’t copy proprietary designs or manuals verbatim.

Document your project with photos and performance logs. This documentation helps with troubleshooting, demonstrates the work quality if you decided to sell the converted machine, and contributes to the growing knowledge base for future builders.

Electric skid steer conversions remain niche but increasingly practical in 2026. With thoughtful engineering, proper motor and battery sizing, and attention to thermal management, these projects deliver quieter, cleaner operation and genuine long-term cost savings. The point isn’t to match every diesel capability—it’s to build a machine optimized for your specific needs while eliminating the noise, emissions, and fuel costs that make diesel operation increasingly impractical.