The terms of battery of volt, Watt, VRLA, maintenance free battery and others

Volt: The unit of measure for electrical potential or voltage.

Voltage Drop: The net difference in the electrical potential (voltage) when measured across resistance or impedance (ohms). Its relationship to current is described in Ohm`s law.

Voltmeter: An electronic device used to measure voltage, normally in a digital format.

VRLA: Valve-regulated Lead acid battery. AGM and gel are the two types of Vrla Deep Cycle Battery. These batteries have no [free" liquid electrolyte and in the cell operate on the oxygen recombination cycle, which is designed to minimize water loss. Deep Cycle Vrla Agm Battery feature vents that are one-way burp valves. These low-pressure burp valves prohibit air ingress to the cell while permitting gases to vent from the cell if necessary. The pressure maintained in the battery, though only very slight ('< 3-psi') is required to facilitate the oxygen generated at the positive plates back into water.

Watt: The unit for measuring electrical power, i.e., the rate of doing work, in moving electrons by, or against, an electrical potential. Formula: watts = amperes x volts.

Watt-Hour (Watt-Hrs, WH): The unit of measure for electrical energy expressed as watts x hours.

Maintenance-Free: A battery that normally requires no service watering during its lifetime of use.

Negative: Designating, or pertaining to, electrical potential. The negative battery terminal is the point from which electrons flow during discharge.

Low Water-Loss Battery: A battery that does not require periodic water addition under normal driving conditions; also referred to as a maintenance-free battery.

MCA (Marine): MCA is an industry rating defining a marine battery`s ability to deliver a large amount of amperage for a short period of time. Since marine batteries are typically never used at temperatures below freezing, marine cranking amps are measured at 32°F as opposed to 0°F for cold cranking amps. The rating is the number of amps that can be removed from a marine battery at 32°F for 30 seconds while maintaining a voltage of at least 7.2 volts for a 12-volt battery. The higher the MCA rating, the greater the starting power of the marine battery.

Equalization Charge: The process of ensuring that the cells and plates within a battery are all at full charge and that the electrolyte is uniform and free of stratification. This is normally done by charging the battery under controlled conditions (charge current, time and upper voltage limits are usually specified).