AGK Electrics ( chapter 3 > required skills and knowledge )

The purpose of the battery is to

Provide a short-term, limited source if electrical energy

Aircraft batteries are either …

1. Lead acid

2. Nickel cadmium ( NiCad )

3. Lithium ( LiB

Nickel cadmium and lithium batteries advantages

1. Power to weight ratio than lead acid batteries

2. And take less time to charge than lead acid a batteries

Nickel cadmium and lithium disadvantages

1. Are prone to thermal runaway because they have a negative temperature coefficient of resistance

A busbar is …

A substantial conductor, powered by an electrical source, which has attachment points to allow connection of multiple loads

A lithium battery fire can be extinguished by

Water or non flammable liquid

If one lithium cell runs away what will happen

It will heat up cells, provoking multiple thermal runaways

Lithium batteries are present in large quantities in aircraft because the aircraft is equipped with

1. Tablets

2. And smart phones

3. Tv entertainment

Thermal runaway

Can be initiated by high internal or ambient temperature, mechanical shock or damage to the battery, or an excessive charge rate

Lithium and nickel cadmium batteries are potentially dangerous because

Of their capacity to thermal runaway

If generated power sources fail in flight what happens

1. Limited amount of electrical power remaining before the battery is exhausted

Norminal battery capacity reduces if …

1. The battery is cold

2. Maximum rate if discharge also decreases

Capacity is measured in

Ampere hours ~ the number of Amp that can be supplied for a given amount of time

Why might a higher nominal charge be needed

When the battery is charging