Battery density is often an important criteria in making a purchasing decision, although the labels in stores seldom mention it specifically. We use the word ‘density’ in other contexts too, for example ‘we drove through dense fog as we neared the coastline’. We may even encounter it in news about an artillery battery laying down a dense barrage of fire. So density means something intense or concentrated? We are getting closer …
More Clues to Understanding Battery Density
Electrochemical batteries contain energy which powers our electrical devices like smartphones, and electric cars. Physics defines energy density as the amount of power stored in a given system, or region of space-per-unit-volume. So therefore we should understand it in the context of the area it ‘occupies’.
Wikipedia goes on to explain the difference between this concept and specific energy, or gravimetric energy density. In this latter instance, we are talking about the amount of energy per unit mass. However, we are still in the same ball park because we are speaking of energy concentration, which is what battery density is all about.
Assessing Battery Quality in Terms of Energy Stored
Quantum Scope is on-topic when it describes how the quality of a battery relates to the energy it stores, relative to its size, or weight. After all, the amount of energy in the battery determines how long our electric vehicle or smartphone will continue, before we need to swap , or recharge the battery.
Battery density therefore refers to how much energy a full battery holds relative to its size, or weight. It follows that we should purchase high density batteries where their weight, or the space they occupy matters to us.
This is what makes lithium-ion batteries so popular among the tech generation. However, we should not turn our backs on alkaline, lead, and other technologies that may have less density, but are safer, lighter on our pockets and also do the job.
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