22 | Battery

In 1866, Georges Leclanché invented a battery known as Leclanché cell.
In 1899, a Swedish scientist named Waldemar Jungner invented the nickel–cadmium battery.
Waldemar Jungner patented a nickel–iron battery in 1899.
In 1912 American physical chemist Gilbert N. Lewis lithium batteries.
In 1980, an American chemist, John B. Goodenough, discovered the LiCoO2 (Lithium cobalt oxide)
In 1997, the lithium polymer battery was released by Sony and Asahi Kasei.

1.3 Hazard

Battery contain chemical that can injured or burn your skin upon contact. Do wash your hands or any other infected area by battery water or chemicals that leaks from its container.
DC is more dangerous when the two lead are touching surface of any metal objects, when DC voltage is higher than 50 volts it produce arcing light like welding.

Obey signage as described below.

NO SMOKING ALLOWED
Wear breathing respirator all time
NO NAKED FLAME IN THIS ROOM

2.0 Battery Cell

Types of battery commonly applies in electrical system or equipment.

non-rechargable also known as ' primary cell '
rechargable also known as ' secondary cell '

Modern batteries to learn more click here .

2.1 Types of primary cell

carbon
carbon zinc
alkaline
mercury
silver oxide (for PC,clock)
lithium (higher voltage)

2.2 Types of secondary cell

lead acid
nickel cadnium (NiCd) (voltage)
nickel iron (NiFe) (current)
lithium
absorb glass mat (AGM)
gel

2.3 Conventional voltage flow

Basically, the voltage flow of battery is positive (+ve) to negative (-ve).

2.4 Electron or current flow

However according to Benjamin Franklin, the current flow is from negative (-ve) to positive (+ve).

(Figure 1) (Figure 2)

Figure battery operating behavior

2.5 Battery Construction

Basic component:

cell unit
container
plates
terminal
solution or liquid cell
paste ( chemical in jelly form)

Figure above typical liquid cell.

(For reference)

3.0 Liquid cell

A wet-cell battery is the original type of rechargeable battery. This solution modifies the molecules in electrolytes, ferrocene and viologen to make them stable, water-soluble, and stop them degrading over time. Types of liquid electrolyte (or battery water).

3.1 How liquid battery works?

When copper and zinc are placed into an electrolyte solution like dilute sulfuric acid or saline solution, the copper atoms barely break down at all, but the zinc atoms break down and electrons flow out. So the copper becomes a positive (+) pole and the zinc a negative (-) pole, and when the two are joined by a conductor, electricity flows from the copper to the zinc. This is the Volta battery, which forms the basis for modern chemical batteries. It was discovered by another Italian named Alessandro Volta, whom the battery was named after, in 1800.

3.2 Liquid cell example

Deep-cycle battery
Valve Regulated Lead Acid (VRLA) battery
AGM battery
Gel battery

4.0 Dry Cell

A dry cell is a type of electric battery, commonly used for portable electrical devices after development of wet zinc–carbon batteries by Georges Leclanché in 1866. The modern version was developed by Japanese Sakizō Yai in 1887.

4.1 Dry Cell History

It was developed in 1886 by the German scientist Carl Gassner, he invented a battery where there was no risk of the solution spilling. Because the battery would not spill even though it contained a liquid, Gassner’s invention became known as the “dry cell” or “dry battery.” In 1900, the great inventor Thomas Edison who was also known to commercialize filament lamps invented nickel-iron storage battery. It is called Edison battery.

4.2 Dry type example

A dry cell uses a paste electrolyte, with only enough moisture to allow current to flow.

lithium
alkaline
nickel iron
carbon-zinc

5.0 Charging System

Basically there a many methods when comes to charging a battery cells, the most widely use methods are:

a. Voltage charging

b. Current charging

5.1 Voltage charging

- suitable for wet cell type

Voltage refers to the stability of charging speed for a charger. The charger works by applying slightly higher voltage to battery cell.

5.2 Current charging

- suitable for dry cell type

Constant voltage / constant current (CVCC) is a combination of the above two methods. The charger limits the amount of current to a pre-set level until the battery reaches a pre-set voltage level. The current then reduces as the battery becomes fully charged.

Battery Effects or Damaged

The following conditions were a battery may suffers damage.

over charging - without releasing the energy to connected load.
over voltage - higher than normal voltage.
temperature rised due to heat and overvoltage charging.
battery internal resistance
battery memory effects - when battery are not constantly charging its cell, it may have this problem.

Today recommend battery

Brand: Panasonic Evolta - best for electronics measurements such as multi-meter, meggar, clamp meter and it improve technology that prevents battery leakage.

Battery Formula

Battery Internal Resistance

This where when battery are not used or charge constantly, may creates

Formula: Internal Resistance

Ri = Vd ÷ IL

Where

Ri internal resistance

Vd voltage drop

IL load current

Example:

Given Vd = 1.5v, IL = 2A

Ri = Vd ÷ IL

= 1.5 ÷ 2A = 0.75 Ω

Formula: Internal Resistance

𝑉𝑑÷𝑉𝑜=𝑅𝑖 ÷ (𝑅𝑖+𝑅𝐿)

Where

Vd voltage drop

Vo voltage open circuit

RL load resistance connected

Ri internal resistance

Example:

2. The open circuit voltage of a lead acid battery is 12 volt. When a 50Ω load is connected to the terminal voltage, it reads 10 volts. Find the internal resistance of the battery (Ri)?

VD = VO – VL VD = 12v – 10v = 2v

𝑉𝑑÷𝑉𝑜 =𝑅𝑖÷(𝑅𝑖+𝑅𝐿)

2𝑣÷12𝑣 =𝑅𝑖÷(𝑅𝑖+50Ω)

2v(Ri+50Ω) = 12 Ri

2Ri + 100Ω = 12 Ri

100Ω = 12v Ri – 2v Ri

100Ω = 10v Ri

Ri = 100Ω ÷ 10v

Ri = 10Ω

Battery Capacity

Battery capacity (AH) is defined as a product of the current that is drawn from the battery while the battery is able to supply the load until its voltage is dropped to lower than a certain value for each cell.

Battery capacity is measured in milliamps × hours (mAH). For example, if a battery has 250 mAH capacity and provides 2 mA average current to a load, in theory, the battery will last 125 hours.

Since battery capacity and performance is reduced by low temperature, a minimum electrolyte temperature of 5°C is maintained as a general rule.

Formula:

To find battery capacity C = t x I

C (ampere hours) = I (current) x t (time in hours)

2. To find current, I = C ÷ t

3. To find discharge time, t = C ÷ I

Series connected battery

When two or more batteries are connected in series together, their voltages and resistances are added together.

Benefits:

current remain same through all battery connected.
voltage will increase
temperature will increase or get heated up.

Parallel connected battery

When more battery are connected in parallel the effects are better in terms of current and voltage stability.

Benefits:

voltage are constants remain same through all battery connected.
current is increased, when charging current must be higher.
temperature will increase or get heated up.
cable connected to battery must be larger size.

Battery connected in series will cause its battery voltage increased but the currents remains same.

Battery in parallel voltage is same but this will help increase battery current. However the dc cable size use in this configuration must be bigger.

Battery Maintenance

Important of battery maintenance is to avoid battery damage or fire risk hazards.

For more information or references visit link below.

https://www.sciencedirect.com/topics/engineering/battery-capacity