Battery Knowledge

7/31/2019 Battery Knowledge

1/4

Home | Search |About ABS | Contact | Our Standard Product | Custom Packs | Online Store | Battery Knowledge | Links

| BATTERY KNOW LEDGE |

Welcome to our battery knowledge page. Here you will find some quick notes onbatteries and battery assemblies. This page is designed to help our customersbecome more familiar with the general principles of battery assemblies. If you havequestions or would like us to add more information relevant to your needs, pleasecontact us.

Basic Assem bly Pr ocess:

Individual cells are glued together into a configuration:

Resistance spot welding is used to attach nickel strip material between the

negative and positive terminals of the cells. This will turn a group of cells into abattery pack that has a voltage which a multiple of the number of cells (forexample: a 10 cell assembly of NiCd or NiMH cells (1.2v per cell) is a 12 voltbattery pack):

Circuit protective devices such as resettable fuses are added to the assembly.

These components usually take the place of the nickel strip mentioned aboveand will act as the connection between cells:

The assembly is often shrink wrapped to insulate the cells and prevent short

circuits:

ry Knowledge http://www.advanced-battery.com/batteryknowl

23-Aug-12


2/4

Finally, if the battery pack is to attach externally to a device, the battery may

be housed in a plastic housing:

Some Typica l Equat ions and Chem ica l React ion s:

Oh m ' s La w : E= I * R (E=Volts, I=Amps, R=ohms)Pow er : P= E* I o r P= ( I * I ) * R (P=Watts)A m p - H o u r s: expected life (hours)*Average amps=Amp-Hours

Current (Amp)=Volts/ResistanceResistance (ohms)=Voltage/CurrentVoltage=Current*Resistance

NiCD:

At the positive

NiOOH + H20 + e- Ni(OH)2 + OH-

At the negative

Cd + 2OH Cd(OH)2 + 2e-

Overall

2NiOOH + Cd + 2H2O 2Ni(OH)2 + Cd(OH)2

NiMH:

At the positive

NiOOH + H20 + e- Ni(OH)2 + OH-

At the negative

MH + OH- M + H2O + e-

Overall

NiOOH + MH Ni(OH)2 + M

(M: Hydrogen absorbing allowy, MH: Metal Hydride)

L it h i um P r ima ry :

At the negative

(Li-Al ) Al + Li+ + e-

At the positive

MnO2 + Li+ + e- MnO2 (Li+)

Overall

MnO2 + (Li-Al) MnO2(Li+) + Al

(Li-Al : lithium alluminum alloy)

Glossary o f Com m on Ba t te r y Term s:


23-Aug-12


3/4

Ba t te r y - a device that converts energy, by chemical reaction or physical

reaction, into electric current.

Pr ima ry Bat t e r y - energy is exhausted when active materials are consumed

(carbon-zinc dry cell, lithium battery, silver oxide battery, alkaline battery)

Secondary Ba t te r y - active materials are regenerated by charging (nickel

cadmium (NiCd), nickel metal hydride (NiMH), Lithium Ion, Lithium Polymer,Sealed Lead Acid.

Ser ies Conn ect ion - Connection of a group of battery cells by sequentially

interconnecting the terminals of opposite polarity thereby increasing the voltageof the battery group but not increasing capacity (i.e. positive to negativeconnections).

Para l le l Connect ion - Connection of a group of batter cells by interconnecting

all terminals of the same polarity, thereby increasing the capacity of the batterygroup but not increasing the voltage (i.e. positive to positive and negative tonegative).

Cadmium - Chemical symbol Cd. This metallic element is the chemically active

material of a nickel cadmium battery's negative electrode. When the battery ischarged, the negative electrode surface consists of cadmium. As the batterydischarges, the cadmium progressively changes into cadmium hydroxide (Cd(OH2)).

Cadmium Hyd rox i de - Active material used at the negative electrode of the

Nickel-Cadmium Cell.Meta l Hyd r i de - A general name for chemical compounds consisting of metal

elements and hydrogen.

Nicke l Hyd r ox i de - The active material in the positive electrode of NiMH and

NiCd batteries.

Nicke l Oxyhyd r ox i de - The chemical name of NiOOH. Indicates that oxidation

of Ni (OH)2 has progressed, and that the active material of the positiveelectrode of an NiCd or NiMH battery is charged.

Capaci ty - The quantity of electricity that can be obtained from a battery in

one cycle from full charge to full discharge when the battery is dischargedunder conditions of rated current level and ambient temperature within thepredetermined range. Generally, capacity is expressed in units of mAh

(milliampere-hour).Nomina l Capac i ty - The standard capacity designated by a battery

manufacturer to identify a particular cell model.

Nomina l Vo l tage - The standard voltage used to express the capacity of a

particular battery model. It is generally equal to its electromotive force or itsapproximate voltage during normal operation. Typical Values:

1.2 volts per cell for NiCd and NiMH

3.6 or 3.7 volts per cell for Lithium Ion or Lithium Polymer

3 volts per cell for lithium primary

2 volts per cell for sealed lead acid

1.5 volts per cell for alkaline and carbon zinc

Discharg e Rate - The discharge rate is the rate at which current is removed

from a battery. When a battery is discharged at a current level "i", for a perioduntil the end discharge voltage is '"h", the discharge is referred to as the h-hourrate discharge, while "i" is known as the h-hour rate discharge current. Forpractical use, nominal capacity is used as standard.

End-Vo l tage - The voltage that indicates the end limit of discharge. This

voltage is almost equivalent to limitation of practical use. Typical values:

1.0 volt per cell for NiCd and NiMH

1.75 volts per cell for sealed lead acid

2.75 volts per cell for lithium ion and lithium polymer

2.0 volts per cell for primary lithium

0.9 volts per cell for alkaline and carbon zinc


23-Aug-12


4/4

Open ci rcu i t v o l tage - The voltage between terminals of a battery without

any load.

Opera t i ng v o l t age - The voltage between terminals when a battery is

subjected to a load. Usually expressed by the voltage of the battery at 50%discharge point.

Po lar i t y Reversa l - Reversing of polarity of the terminals of a small-capacity

cell in a multi-cell battery due to overdischarge.

Posi t i v e Elec t rode - The electrode which has a positive potential. Electric

current from this electrode flows in the external circuit during discharge.

Negat i ve Elec t rode - The plate which has an electrical potential lower than

that of the other plate during normal cell operation. Electric current from theexternal circuit flows into the cell at the negative electrode during discharge.Also called minus electrode.

Se l f -D ischarge - a decrease in battery capacity which occurs without any

current flow to an external circuit. Typical values:

1% per day for NiCd

2% per day for NiMH

~0% per day for Lithium Ion and Lithium Polymer

Short Ci rcu i t - Directly connecting the positive electrode (terminal) to the

negative electrode (terminal) of the battery.

The rmis to r - A circuit element with a negative temperature coefficient. It is

built into batteries and used to detect ambient temperature or batterytemperature. A battery charger may use this device to properly charge abattery.

Online Privacy Policy | Terms of Service


23 Aug 12

Battery Knowledge

Documents

Transcript of Battery Knowledge