A 24V twin-motor hydraulic power unit is worth considering when a correctly matched single-motor unit can lift the load but moves too little oil to give you a practical cycle time. Large-bore cylinders, long-stroke telescopic hoists and larger scissor-hoist systems can require substantial oil volume.
Primary Mover offers single-acting and double-acting Twin Engine power units. These use two electric motors to support higher hydraulic flow. The upgrade addresses speed and productivity while preserving the pressure and structural limits of the equipment.
More Flow Does Not Increase the Equipment's Lifting Rating
Pressure acting over the cylinder's effective area produces force. Delivered flow determines how quickly that cylinder moves.
If a single-motor power unit already reaches the correct working pressure, a compatible twin-motor unit can provide more flow at that pressure. That can move the same cylinder and approved load faster.
The additional motor does not increase the hoist's structural rating, trailer payload or cylinder pressure limit. It also does not correct an overloaded trailer or unsuitable mounting geometry.
Read our 2,500 vs. 3,200 PSI pressure-and-flow guide for the relationship between cylinder force, working pressure and lifting speed.
Why Large Cylinders Can Feel Slow With One Motor
A larger cylinder needs more oil for a given amount of movement. Increasing bore diameter or stroke increases the volume the power unit must deliver.
A single-motor unit may supply enough pressure to raise the load successfully, yet take longer than you want to fill a large cylinder. This becomes noticeable on larger scissor hoists and long-stroke telescopic systems.
For example, a conventional 6-inch-bore cylinder with a 20-inch stroke needs approximately 2.45 US gallons for full base-end extension:
- At a constant delivered flow of 1 GPM, calculated extension time is approximately 2 minutes, 27 seconds.
- At a constant delivered flow of 2 GPM, calculated extension time is approximately 1 minute, 13 seconds.
This is a calculated illustration, not a measured comparison or a flow rating for a particular unit. It shows why more delivered flow can make a substantial difference when the cylinder has a large oil requirement.
How Much More Flow Should You Expect?
For comparable, properly matched arrangements, the aim of a twin-motor design is a substantial increase in flow, potentially approaching twice the single-motor output. The actual result depends on pump displacement, operating pressure, motor speed, voltage, oil temperature and system restrictions.
If a single-motor arrangement delivers 1 GPM at a particular pressure, 2 GPM at that same pressure would represent twice the flow. It does not follow that every twin-motor unit delivers exactly twice the output of every single-motor unit.
Compare flow at the pressure your equipment needs. Low-pressure output and output near the approved lifting-pressure limit are different operating points. Use the selected model's pressure-and-flow information when estimating cycle time.
A full dump cycle also passes through changing loads and geometry, so a doubled flow figure at one test point does not guarantee that every real-world cycle takes exactly half as long.
Choose Single Acting or Double Acting for the Application
| Primary Mover Version | Operation | Typical Application |
|---|---|---|
| Single-acting Twin Engine | Power up, gravity down | Compatible single-acting telescopic hoists and other gravity-return systems |
| Double-acting Twin Engine | Power in both directions | Compatible larger scissor hoists and cylinders requiring powered retraction |
The circuit must match the cylinder and its control requirements. A double-acting model is not automatically a suitable replacement for a single-acting telescopic system.
Reservoir selection remains important. A single-acting telescopic cylinder needs enough usable tank volume to supply its working oil and accept the returning oil. Double-acting systems have different net volume requirements, along with reserve and expansion needs.
See Single-Acting vs. Double-Acting Hydraulic Power Units for the circuit and reservoir differences.
Why Primary Mover Uses 24V for These Twin-Motor Units
Driving a higher-output hydraulic system takes electrical power. At comparable input power, doubling the supply voltage approximately halves the bank current:
Electrical power = voltage × current.
The following example uses the same 7,200-watt electrical load at two nominal voltages:
| Supply Voltage | Example Input Power | Calculated Bank Current |
|---|---|---|
| 12V | 7,200 watts | 600 amps |
| 24V | 7,200 watts | 300 amps |
These are electrical calculations, not measured current ratings for the products. Actual current varies with load, voltage and efficiency. Starting conditions also matter when selecting components.
A high-output 12V system can be engineered, but its higher current places substantial demands on the shared cables, connections and switching components. A 24V supply makes that current easier to manage for these twin-motor applications.
For unchanged wiring resistance, halving current reduces resistive heating to one-quarter because cable loss follows I²R. Actual installation losses depend on the cables and connections used. The system still needs correctly rated components and suitable cooling periods.
The voltage change does not halve the energy needed to do the work. The twin-motor design supplies more hydraulic output; the 24V supply supports that output with lower current in the shared power path.
Plan the Battery Bank and Charging System
Two suitable 12V batteries connected in series provide a nominal 24V bank. Use batteries matched to the application and approved for that connection. Capacity, discharge capability, condition and battery-management limits all matter.
Follow the power unit's wiring diagram. Supply voltage alone does not authorize changing the internal motor connections or applying 24V to a unit designed for 12V.
Plan a compatible charging arrangement for the complete bank. A normal 12V trailer charge feed cannot directly charge the full 24V bank; use an approved 24V charging solution or properly specified conversion equipment.
Confirm cable lengths, conductor sizes, terminals, isolation and overcurrent protection with the installation requirements. Even at 24V, this is a high-current system.
Check Each Battery, Not Just the Combined Voltage
A battery bank can show a reasonable resting voltage and still perform poorly under load. Check the individual batteries as well as the complete bank.
With batteries connected in parallel, a shared voltage reading does not show how evenly they are contributing. In a series bank, a weak battery can cause voltage sag or imbalance that limits the entire system.
Series wiring does not guarantee that a failing battery will always reveal itself before a job. Use the battery manufacturer's testing procedure and check performance under load. Test or service a mismatched bank before relying on it in the field.
When the Upgrade Makes Sense
- Your existing unit reaches the approved lifting pressure, but cycle time is too long for the job.
- Your cylinder has a large oil-volume requirement because of its bore, stroke or telescopic design.
- The cylinder, valves, hoses and return path are suitable for the proposed increase in flow.
- You have space and a plan for the required battery bank, reservoir and charging equipment.
- You have checked electrical faults, restrictions and oil condition before attributing slow operation to single-motor capacity.
Match the selected unit's pressure setting to the exact equipment. Telescopic and scissor-hoist applications can have different approved pressures. More available motor power does not authorize a higher setting.
Common Questions
Does 24V Alone Make a Hydraulic Power Unit Faster?
No. A 24V label alone does not establish hydraulic output. Speed depends on delivered flow. The extra motor and matched hydraulic arrangement provide the flow increase in the Twin Engine design.
Does Twin Motor Mean Double Acting?
No. Twin motor describes the two electric motors. Single acting and double acting describe how the hydraulic circuit moves the cylinder. Primary Mover offers both circuit types in the Twin Engine range.
Will Twin Motors Make a Gravity-Down Bed Lower Faster?
Additional motor power does not directly speed gravity lowering when the motors are off. Descent depends on the return path, valve capacity, fluid and load. Powered lowering on a double-acting system also requires suitable load control and return capacity.
Can a Twin-Motor Unit Fix a Weak Battery?
No. Resolve battery, cable and connection problems first. A higher-output unit requires an electrical supply capable of supporting its operating demands.
Explore Primary Mover Twin Engine Power Units
View the Primary Mover single-acting Twin Engine power unit for compatible gravity-return applications, or the Primary Mover double-acting Twin Engine power unit for powered extension and retraction.
Browse 24V hydraulic power units or call 985-888-6554 with your cylinder model, current cycle time and electrical-system information. We can help determine whether the flow upgrade suits your application.