-Valve regulated lead acid battery.
A Plastic material largely used for the case and cover of batteries.
Positive Plate ：
The battery electrode from which a current flows to the external circuit during discharging. The positive plate has higher electric potential than the negative plate to the electrolyte. The positive plate is incorporated with connection parts such as the electrode pole.
Negative Plate ：
The battery electrode into which a current from the external circuit flows during discharging. The negative plate has lower electric potential than the positive plate to the electrolyte. The negative plate is incorporated with connection parts such as the electrode pole.
Nominal Voltage ：
A nominal value to indicate the voltage of a cell battery. Generally, nominal voltage value of a battery is somewhat lower than its electromotive force. Nominal voltage of the lead-acid battery is 2.0 V per unit cell.
Open circuit Voltage (OCV):
Measured voltage of a cell/battery which is electrically disconnected from the external circuit.
Rated Capacity ：
The stated capacity of a battery; namely, the ampere-hour amount can be drawn from the battery in fully charged state at a specified temperature, at a specified discharge rate, and to a specified cut-off voltage. The symbols CN may be used to express the rated capacity of N-hour rate.
The medium which serves to conduct ions in the electrochemical reactions in batteries. The lead-acid battery adopts diluted sulfuric as the electrolyte.
A porous or micro porous liquid-absorbent material which is installed between the battery electrodes for preventing short-circuit, securing the separation of the electrodes and retaining electrolyte.
a valve on each battery which automatically releases gas from the battery when internal pressure of the battery exceeds a pre-demined value: it prevents breakage of the battery due to excessive internal pressure caused by the gas generated by charging or other reasons. The valve also serves to prevent outside air from entering batteries.
-Chemical symbol for lead.
The substance which electrochemically reacts in the electrode of batteries. Lead-acid batteries adopt lead dioxide for the positive electrode and spongy lead for the negative electrode.
Average temperature in the vicinity of the battery.
A type of battery terminals, to which lead wires are connected with bolts.
The minimum battery unit which composes a storage battery. Nominal voltage of the cell of the lead-acid battery is 2V.
The operation of supplying a battery with a DC current from an external power source to have the electrode active material conduct chemical reactions then to store electric energy as chemical energy in the battery.
Constant current charge ：
A method of charging: to charge a battery with a constant current.
Over Charged ：
Continued charging of a fully charged battery. Overcharge causes electrolysis of water, resulting in rapid decrease of electrolyte. Generally, overcharge adversely influences battery life.
Float Charge ：
The system in which a constant voltage is continuously applied to a battery connected to a rectifier in parallel with a load to maintain the battery in charged state: on occurrence of power failure or load variation, the battery supplies power to the load without any short break.
Quick Charge/Rapid Charge：
Charging in a short time with a large current.
Refresh Charge / Auxiliary Charge ：
Charging of a battery mainly to compensate for its self discharge.
Trickle Charge ：
To charge a battery in the state of disconnection from the load to compensate for its self discharge.
To draw off the electric energy stored in a cell/battery.
Self Discharge ：
Reduction in capacity of a battery while no current is draw by the external circuit. Self discharge depends on temperature: amount of discharge approximately doubles by each (10¡ãC) rise of ambient temperature.
The term to express the magnitude of discharge current. When assuming discharge current and time to discharge cut-off voltage t hours, this discharge is called t-hour rate (tHR) discharge, and the current is called t-hour rate discharge current. When time t is minutes instead of hours, tMR is used.
Over discharged ：
Discharge of a battery to a voltage below a predetermined cut-off voltage.
High Rate Discharge ：
A very rapid discharge of a battery. (in many cases it means discharging at approx.1 CA or higher rate.)
A charge or discharge current rate expressed in A or mA. It is numerically the same as the hour rate capacity of a battery expressed in Ah of the rated capacity.
Cut-Off Voltage of Discharge ：
The terminal voltage of a battery at which discharging be discontinued. This voltage depends on discharge current, type of electrodes and construction of battery.
Depth of Discharge ：
A value to express the state of discharge of a battery. The depth of discharge is generally expressed by the ratio of discharge amount to rated capacity of the battery.
Cycle Life ：
The number of charge/discharge/rest cycles a cell/battery can provide. Cycle life is usually expressed by the number of cycles available before duration of discharge decreases to a half of the initial value.
Gas Recombination Ability:
Capability of a battery to recombine (or absorb) internally generated oxygen gas at the negative plate. The greater this capability is, the larger the available charge current.
Internal Pressure ：
The pressure within a sealed battery. Internal pressure of a battery is increased by oxygen gas which is generated from the positive plate at the end of charging.
The resistance within a battery; it is the total of individual resistances of the electrolyte and the positive and negative plate. Internal resistance is simply measured with the current four-terminal method(1,000Hz) and expressed in the composite value of resistance component and capacitor component.
Internal Short Circuit ：
Touching of the positive and negative plates within a call.
Maintenance Free ：
Low maintenance means that no watering nor equalizing charge is required in operating batteries.
Energy Density ：
Energy available per unit approx. mass or unit volume of a cell/battery. Energy density is expressed in Wh/kg or Wh/l.
Low Voltage Cut off ：
A circuitry designed to discontinue discharge of a battery at a predetermined voltage level.
Memory Effect ：
A phenomenon where a temporary drop of discharge voltage is observed during deep discharge of an alkaline rechargeable battery which has been subjected to shallow charge/discharge. Cycles or trickle charging over long time.
General term of constant stand-by battery systems. Batteries are kept charged by trickle/float method at all times in preparation for unforeseen power disruptions.
Terminal Voltage at Discharge ：
The voltage of a battery during discharge.
Thermal Runaway ：
Such phenomena as an excessively high set-up voltage in constant-voltage charging of a battery and a very high battery temperature cause charge current to increase, which than raises the temperature further: this vicious cycle is called thermal runaway, which may, in the worst case, result in breakage of the battery due to heat.