A hydraulic winch operates off of the hydraulic system of a vehicle, in most cases, the power steering pump. The hydraulic winch does not require a powerful battery to operate and in most versions, will pull harder and longer than a comparably sized electrical unit. The winch also has the capability of operating while completely submerged in water. Perhaps one of the best attributes of the winch is its ability to pull for longer periods than an electric winch without over-heating.
Another benefit of the hydraulic winch in vehicle-mounted applications is its superior operation in cold climates. By virtue of being powered by the vehicle's power steering pump, the hydraulic fluid is pre-warmed prior to entering the winch motor. This warm hydraulic fluid keeps the winch's motor warm and ready to operate even in cold weather. The warm winch is able to pull harder than a cold winch and produces better results.
An electric motor produces heat and can draw enormous amounts of energy from a battery. As the winch encounters difficult pulling conditions, the motor can begin to overheat. The electric winch can lose power and actually begin damaging the winch motor, often on the initial use of the winch. This results in a weaker and less-effective winch at each and every use of the device.
The hydraulic winch is not damaged by ordinary use and will not become overheated if a difficult pull presents itself. The winch will continue to pull as hard from the on-start of the pull until its completion. It is rarely required that the engine on the winching vehicle ever be operated at any speed above an idle to operate the winch. The vehicle's power steering pump provides the required power right from idle.
A primary drawback to the hydraulic winch is that the winch will only work while the vehicle's engine is running. In some circumstances, that can be a hindrance to the winch's usefulness. Another drawback lies in the fact that a broken power steering line not only makes the vehicle more difficult to steer, it also makes the winch inoperable.
The battery system in any vehicle is designed to operate at high-power output for a brief period, such as in starting the engine. The winch is designed to operate at full power draw for long periods of time. Herein lies the main problem with an electric winch. The vehicle's battery and charging system is over-taxed when trying to supply power to the winch. The hydraulic winch may be the better answer for reliability as well as durability in a vehicle-mounted winching system.