I'm a 30-plus-year veteran of electrical engineering with experience that spans many areas, including digital, analog, power, communications, and microcontrollers. I work for a company called MaxVision, which makes extreme-performance, ruggedized, transportable workstations. By some strange quirk of fate, Max Maxfield the (world's go-to techno guy) has his office in the same building as mine. Over the years, he has had to tolerate my very bad punny humor attempts over the coffee table, since we share a kitchen in our building.
One day, while I was contemplating a new joke to inflict upon everyone, I overheard a conversation between Max and our mechanical design expert, Eugene "Willie" Richards, about what type of batteries would be the best option for Max's robot project. Since I have considerable knowledge about batteries (robots too), and I was feeling some remorse about my previous puns, I held off on the jokes and offered my assistance.
Max said it would be useful to a lot of readers if I wrote a series of columns on batteries -- beginning with types, technologies, terminologies, specifications, and environment. Later we will cover specific types of batteries in more detail, considering most everything required to understand and select the appropriate technology for a particular application. Once we've considered everything in excruciating detail, we will be in a position to advise Max about the optimal battery technology for his robot.
The battery was invented by Alessandro Volta of Italy in 1800. I'm sure Volta would be amazed by how ubiquitous (and varied) his invention has become. Having said this, for some tasks, it might be more appropriate to select a capacitor, rather than a battery. Surprised? Well, you might at least consider using a capacitor whenever it is assured to have a regular, high-surge-capable supply of electricity. In some cases involving very light loads, it might even be possible to ignore the regular power application -- just charge a super-capacitor once, and it will survive all the way until discarded. Once we have discussed battery terminologies and technologies, the capacitor versus battery choice will hopefully become clear.
There are lots of factors to consider when choosing the battery technology for a particular application. In addition to relative size, weight, and cost (from cheap to expensive to "if you have to ask, you can't afford it"), the main considerations and factors I plan on covering in this series are as follows:
- Environment (operating and storage): Temperature, air pressure, altitude, mechanical strain, vibration, mounting position, radiation hardening, corrosive attack, packaging/shape, storage or shelf life, disposal, waste products produced and outgassing, consumables required, safety, and materials/RoHS
- Application: Types (including primary, secondary, and smart), technology, chemistries, efficiency and loss, charge/discharge cycle count and rates, depth of discharge, service life, memory effect, charging techniques, capacitor/battery hybrid, use cases, capacity, density (energy and weight), protection circuitry, measuring and gas gauge, quality, reliability, and recharge and run times
Since Volta's first crude models, many types of batteries have come into use. Some of these technologies are as follows.
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|NiMH||Nickel metal hydride|
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|ZnMnO2||Zinc-manganese dioxide (alkaline) |
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|LiSOCl2||Lithium thionyl chloride|
|LiCFX||Lithium poly carbon monofluoride|
|LiSO2||Lithium sulfur dioxide|
|LiAlCl4||Lithium aluminium chloride|
|LiCoO2 (LCO)||Lithium cobalt oxide|
|LiFePO4 (LFP)||Lithium iron phosphate|
|LiMn2O4 (LMO)||Lithium manganese oxide|
|LiNiMnCoO2 (NMC)||Lithium nickel manganese cobalt oxide|
|LiNiCoAlO2 (NCA)||Lithium nickel cobalt aluminum oxide|
|Li4Ti5O12 (LTO)||lithium titanate|
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| Na2S4 (NaS)||Sodium sulfur|
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|Nuclear or atomic|| |
I won't be able to cover all these technologies in depth -- just some of the more common and/or noteworthy ones. Please add a comment below if you think I've omitted some important technology or if you're interested in a particular one. If you need more information right now, you may find quick, specific answers to your battery-related questions at the
Battery University website.
In my next column I'll cover classifications, general specifications, and terminology. Until then, please post any questions or comments below.