What Is a Hybrid Car Battery?
A hybrid car battery is like any other battery—except that it is rechargeable and has enough juice to move a large heavy vehicle down the road for a few feet or a few miles.
How Does It Work?
Like all batteries, hybrid batteries have two electrodes (which collect or emit an electric charge) that sit in an ion-rich solution called the electrolyte. (An ion, by the way, is an atom or group of atoms with an electrical charge.)
The electrodes are typically very close, so a polymer film, called a separator, prevents them from touching, which would create a short circuit. An on-off switch in whatever device is powered by the battery—your phone or laptop—bridges the cell’s electrodes to generate power. That’s when the electrochemical reaction begins.
Keep in mind: What we commonly call “a battery” is actually a battery pack that houses many individual cells. Your mobile phone battery is just one single cell, but anything larger—even a laptop battery—uses multiple cells working together.
Ionized elements in one electrode are in a chemical state where they are easily attracted to combine with other molecules, emitting electrons (energy) in the process. Those elements are tugged through the electrolyte and the separator toward the opposing electrode. The ions of the negative electrode (anode) give up electrons; the positive ions coming toward the anode accept them. The electrons released during this process travel through the external circuit (e.g. your phone), producing a flow of charge in the opposite direction to the flow of ions. During recharge, current is forced into the cell, reversing the process.
As we take a tour of hybrid batteries, remember one thing: Total energy determines the vehicle’s electric range, whereas available power determines its acceleration.
Today’s Hybrid Car Battery: Nickel Metal Hydride
Toyota Prius Hybrid Battery
The battery pack of the second generation Toyota Prius consists of 28 Panasonic prismatic nickel metal hydride modules—each containing six 1.2 volt cells—connected in series to produce a nominal voltage of 201.6 volts. The total number of cells is 168, compared with 228 cells packaged in 38 modules in the first generation Prius. The pack is positioned behind the back seat.
The weight of the complete battery pack is 53.3 kg. The discharge power capability of the Prius pack is about 20 kW at 50 percent state-of-charge. The power capability increases with higher temperatures and decreases at lower temperatures. The Prius has a computer that’s solely dedicated to keeping the Prius battery at the optimum temperature and optimum charge level. The Prius supplies conditioned air from the cabin as thermal management for cooling the batteries. The air is drawn by a 12-volt blower installed above the driver’s side rear tire well.
(Photos courtesy of the Automotive Career Development Center.)
Toyota Highlander Hybrid Battery
The nickel metal hydride battery used in Highlander Hybrid—and the Lexus RX 400h—is packaged in a newly developed metal battery casing. The 240 cells can deliver high voltage of 288 volts—but the motor-generators units can operate on variable voltage anywhere from 280 volts to 650 volts. The battery pack supplies 288 volts, but the boost converter, a part of the inverter above the transaxle, changes this to 500 volts. This battery pack provides 40 percent more power than the Prius battery, despite being 18 percent smaller.
Each of the modules has its own monitoring and cooling control system. The cooling performance reduces efficiency losses due to excessive heat, ensuring that the battery can supply required electric power to the motors at all times. The battery-monitoring unit manages discharge and recharging by the generator and motors to keep the charge level constant while the car is running. The battery pack is stowed under the rear seats.
Ford Escape Hybrid Battery
The Ford Escape Hybrid’s battery pack, made by Sanyo, consists of 250 individual nickel metal hydride cells. As with other hybrid battery packs, the cells are similar in shape to a size D flashlight battery. Each individual battery cell, contained in a stainless steel case, is 1.3 volts. The cells are welded and wrapped together in groups of five to form a module. There are 50 modules in the battery pack. The total voltage of the battery pack is 330 volts.
Honda Insight Battery
The Honda Insight’s battery pack, made up of 120 Panasonic 1.2-volt nickel metal hydride D cells is capable of 100A discharge, and 50A charge rates. The system limits the usable capacity to 4ah to extend battery life. Total battery pack output is 144 volts. The batteries are located under the cargo compartment floor, along with the Honda Integrated Motor Assist’s power control unit. Honda used technology developed for its EV Plus electric car for the original development of the Insight’s battery system.
Saturn Vue Hybrid Battery
The Saturn Vue Green Line’s 36-volt nickel metal hydride battery, designed and made in America by Cobasys, is capable of delivering and receiving more than 14.5 kW of peak power. The hybrid system is used to provide both 12-volt accessory power and power to charge the battery pack. The pack fits under the cargo area, leaving cargo room unchanged from the standard Vue—but drivers lose the benefit of a spare tire
0 Komentar