28 - 12-Volt and HV Battery Technology

flywheel battery

A generator that uses the kinetic energy of a high-speed AC armature (flywheel) to store huge amounts of electrical energy.

flywheel generator

A generator that uses the kinetic energy of a high-speed AC armature (flywheel) to store huge amounts of electrical energy.

deep cycling

Allowing a battery to use 50-80% of its energy before charging.

cold cranking rating

Amount of current (in amperes) the battery can deliver for 30 seconds at 0°F (-18°C), while maintaining terminal voltage of 7.2 volts (1.2 volts per cell).

battery cycling

Amount of time between the discharging and charging of battery cells.

battery cell

Battery division made up of a negative and positive plate, container, and electrolyte. An HV battery uses an acidic lithium paste or gel, while a lead-acid battery uses liquid sulfuric acid as an electrolyte.

negative post

Battery post marked in black or green and with a negative (-) symbol. It is smaller than the positive battery post.

positive post

Battery post marked in red and with a positive (+) symbol. It is larger than the negative battery post.

battery pack voltage

Between 7.2-9.2 volts, depending on the number and types of battery cells.

negative battery cable

Cable that is normally black and connects to ground on the engine block or frame.

positive battery cable

Cable that is normally red and fastens to the starter solenoid.

HV motor-generator cables

Cables electrically connecting three-phase alternating current from the power control module to the motor-generator with each cable carrying a single phase of AC.

HV power cable

Consists of all large-diameter, high-voltage conductors wrapped in orange plastic insulation that electrically connect the HV battery, HV power control module, and motor-generator.

battery heat shield

Cover or plate that fits over the battery or between the engine and battery to protect it from excess engine heat.

discharging

Current and electrons flowing out of the battery cells, or the release of stored energy. This is a conversion of chemical energy into electrical energy by the battery.

charging

Current flowing back into battery cells from a charging system that can be stored until needed. This is a conversion of electrical energy into chemical energy by the battery.

battery charge indicator

Device designed into the battery cover that provides a visible sign of the general charge condition of the battery.

battery eye

Device designed into the battery cover that provides a visible sign of the general charge condition of the battery.

test indicator

Device designed into the battery cover that provides a visible sign of the general charge condition of the battery.

fuel cell

Device filled with electrolyte and made of a plastic, gas-permeable membrane sandwiched between a positive and negative electrode plate that combines hydrogen and oxygen to produce electrical energy. It is electrolysis in reverse.

load

Electric current-using device.

HV capacitor bank

Electrical energy storage device that does not require an electrolyte, but consists of at least two electrical conductors separated by an insulator. HV capacitor banks are light, wear-proof, and can accept or output short bursts of high-power electrical energy.

12-volt battery

Electrochemical device that produces and stores electricity. An automotive battery is a 12-volt battery with six cells, which produce 12.6 volts to power the vehicle's 12-volt main electrical system.

HV battery ECM

Electronic control module that interprets signals from HV battery temperature and voltage sensors to avoid battery overheating.

HV battery cover

Enclosure that holds high voltage battery modules to protect against damage.

side terminal

Female-threaded electrical connection located on the side of a battery. It connects with a special bolt on the battery cable end.

gassing

Formation of acid fumes during the chemical reaction inside the battery. This involves the conversion of water in the electrolyte into hydrogen and oxygen.

battery pack fuse

Fuse that will burn open to isolate a failed battery pack from the rest of the battery if current flow is too high.

battery case

High-quality plastic housing divided into compartments that hold the battery elements and electrolyte. It is designed to handle extreme conditions and corrosive elements.

HV battery

High-voltage nickel metal hydride or lithium-ion battery capable of 100-300 volts of electricity. They are used alongside a conventional 12-volt lead-acid battery in many hybrid vehicles.

battery bank

High-voltage nickel metal hydride or lithium-ion battery capable of 100-300 volts of electricity. They are used alongside a conventional 12-volt lead-acid battery in many hybrid vehicles.

battery stack

High-voltage nickel metal hydride or lithium-ion battery capable of 100-300 volts of electricity. They are used alongside a conventional 12-volt lead-acid battery in many hybrid vehicles.

hybrid battery cell

Individually sealed rechargeable battery containing a semi-solid electrolyte around positive and negative plates. Each nickel-metal hydride (NiMH) or lithium-ion cell generates about 1.2-1.6 volts DC.

intercalation

Inside a rechargeable battery, the reversible embedding of protons and electrons in the porous electrode materials between the positive and negative battery plates.

amp-hour rating

Measurement of how much current a battery can produce for 20 hours at 80°F (27°C) with battery voltage staying above 10.5 volts.

HV battery peak power rating

Measurement of the amount of current that can be fed to the HV motor for a short period of time. This can determine the vehicle's acceleration speed with full-electric propulsion.

HV battery continuous power rating

Measurement of the amount of voltage and current that can be safely generated before the battery is fully discharged.

HV battery frame

Metal holder that secures the battery packs together and attaches them to the vehicle frame.

battery acid

Mixture of 35% sulfuric acid and 65% distilled water housed in each cell of a lead-acid battery. This solution creates a chemical reaction that releases electrons.

electrolyte

Mixture of 35% sulfuric acid and 65% distilled water housed in each cell of a lead-acid battery. This solution creates a chemical reaction that releases electrons. It is commonly referred to as battery acid.

separator

Permeable membrane that fits between battery plates to prevent shorting. It must be resistant to acid and oxidation.

connector

Plastic or rubber device with metal terminals or connection points for joining the ends of two or more wires.

battery cover

Plastic piece that is bonded to the top of the battery case to seal it.

battery cap

Plastic piece that snaps into the hole above each battery cell to prevent electrolyte from spilling out of a battery and gases inside a battery from igniting.

battery tray

Plate on which the battery sits, usually found in the engine compartment. The retainer fastens to the tray to help securely hold the battery in place.

HV battery amp-hour rating

Rating that compares the electrical power available for one hour of continuous discharge. This is the equivalent of the cold cranking rating.

battery post

Round metal terminal that protrudes from the battery cover and serve as male connections for the female battery cable ends.

battery temperature sensor

Sensor found in many late-model vehicles that monitors battery temperature, providing the ECU with data on when to vary the battery charging rate.

HV battery temperature sensor

Sensor that monitors the temperature of an HV battery to prevent battery thermal and overheating damage.

HV battery pack

Set of low-voltage battery cells wired in a series to produce a high-wattage means of storing chemical/electrical energy. Each battery pack has six or more battery cells enclosed in a housing.

battery plate

Stiff mesh framework each grouped in a battery cell and coated with porous lead that allows penetration of electrolyte to aid the chemical reaction of electricity production within the battery.

battery strap(s)

Strap with two ends that attach to opposite battery terminals creating a handle to lift and carry a battery. Also, within a 12-volt battery, lead bars that connect the positive and negative battery plates into similar groups. They are also called connectors.

battery hold-down

The individualized bracket and fasteners that hold a battery in its tray.

retainer

The individualized bracket and fasteners that hold a battery in its tray.

HV battery nominal operating voltage

The maximum DC voltage available from the HV battery.

open circuit voltage

The voltage between a two-terminal device without a load connected. Each battery cell has an open circuit voltage of 2.1 volts, giving a series-wired automotive six-cell battery a 12.6 open circuit voltage.

reserve capacity rating

Time needed to lower 12-volt battery terminal voltage below 10.2 volts at a discharge rate of 25 amps. The rating assumes that the test starts with a fully charged battery at 80°F (27°C).

HV battery cables

Two orange conductor cables that connect direct current to the HV power control module.

battery terminal

Two top post or two side links that provide a means of connecting the battery plates to the vehicle's electrical system.

dual voltage system

Type of electrical system that uses both a 12-volt battery and high-voltage battery, each wired separately. The conventional 12-volt system powers most of the electrical/electronic circuits while the HV battery powers the double-ought (00) conductors and the HV motor-generator of modern electric drive trains.

gel battery

Type of lead-acid battery that contains the electrolyte in a paste-like consistency instead of a liquid. This allows the battery to still function without any electrolyte leakage if the battery case breaks.

maintenance-free battery

Type of lead-acid battery that does not have removable filler caps. Calcium in the battery plates reduces the battery gases and eliminates the need for water to be periodically added to the electrolyte.

AGM battery

Type of sealed lead-acid battery that contains fiber matting which absorbs liquid electrolyte and holds it between the battery plates.

absorbed glass mat battery

Type of sealed lead-acid battery that contains fiber matting which absorbs liquid electrolyte and holds it between the battery plates.

battery cables

Wires, usually #10 gage to #1 gage copper conductor with plastic insulation and metal terminals, that connect the battery terminals to the vehicle's electrical system.