Electric and hybrid vehicles are not new inventions, but they have become increasingly popular on the roads in the last two decades. These vehicles – and their engines – were developed specifically to be cleaner and more fuel-efficient. The Honda Insight and Toyota Prius were two of the first hybrid vehicles but, today, hybrid technology is being used in everything from econoboxes to full-sized SUV’s and has become an accepted and proven technology. As the technology has advanced, full-on electrically driven vehicles like the Chevrolet Volt and the Teslas have also proven themselves as successful alternatives.

Electric vehicles gained a reputation for not being as reliable or efficient as traditional motors. The cost, size, and weight of the battery were not practical. So what has changed to make these hybrid engines competitive in mobile hydraulic machines?

Technology is No Longer a Barrier

First, battery technology has improved by leaps and bounds over the lead-acid batteries used in standard automobiles. Today, nickel metal hydride and lithium-ion batteries produce over twice as much energy per pound as a lead-acid battery. This means you can store a lot of energy in half as much space, plus the batteries have a longer life, require less maintenance, and have better recharging characteristics. This technology improvement has been pushed by the automakers and will continue to evolve over time. When first introduced, this technology was really expensive. As with all technologies adopted by the automakers, the price comes down as production volume goes up.

Second, the motor technology has improved. Today’s AC motors feature brushless technology and are virtually maintenance free. They are capable of operating under high loads for extended periods of time without damage, unlike some brush type DC motors. These motors are also available in a completely sealed housing so that they can operate in most any environment that your machine would see. Further, these motors are more compact when compared to their DC brothers.

But wait a minute, the batteries store DC voltage and the motors run on AC. How does that work? Well, that leads us to the third part of the system, the inverter. With today’s electronic technology, robust, compact DC to AC inverters deliver the battery power to your motor.These new drives are rugged and have CAN Bus communication capability so your machine’s PLC can directly communicate with it. This also simplifies setup and tuning of the drive.

This technology is available for you to apply to your mobile machine today! Why would you want to use it? Learn more about that in our “Avoid Tier 4 Requirements by Using a Hybrid Drive” article.

How Hybrid Drives Benefit Mobile Machines

Most machines don’t operate at peak power all of the time, but the engine has to be sized to provide peak power. Hybrid technology allows you to use a smaller engine to power the generator. The generator charges the batteries and keeps them charged up unless the machine is worked for long periods at peak power. The batteries can provide continuous power for moving the machine from place to place (while excess current charges the batteries) and peak power for lifting loads or doing other heavy work (drawing from the batteries). If you have a 100 HP machine that operates at peak power less than 50% of the time, you may be able to drive it with a 50 HP engine. That engine will burn less fuel, be quieter, less expensive and take up less space on your machine. It also could be Tier 4 exempt if you can get by with a 25 HP engine.

But can electric drives really do heavy work? Yes, they can! R.G. LeTourneau successfully produced electric powered earthmoving equipment back in the late 1930’s with old technology! He would have loved to have gotten his hands on today’s technology.

If you’re interested in an all-electric or hybrid drive for your machine, contact the experts at the Mobile Hydraulics & Controls Group of Cross Company today!