Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [batteries]

An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy.

An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Each battery consists of a negative electrode (anode) that holds charged ions, a positive electrode (cathode) that holds discharged ions, an electrolyte that allows ions to move from anode to cathode during discharge (and return during recharge) and terminals that allow current to flow out of the battery to perform work.

There are primary cells, which are not rechargeable, and secondary cells, which are. Common types of batteries include lead-acid, alkaline, NiCd, NiMH, and lithium-ion.

Further reading

An Accurate Electrical Battery Model Capable of Predicting Runtime and I–V Performance (2005)

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Why is there so much fear surrounding LiPo batteries?

I've been trying to design a charging system for a small robot powered by a 2S 20C lithium polymer (LiPo) battery. Were I to trust everything I read online, I would believe that the LiPo will kill me in my sleep and steal my life savings. The common…
Cerin
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Why are there 3 pins on some batteries?

Lots of new batteries (for mobile devices, MP3 players, etc) have connectors with 3 pins. I would like to know what is the purpose of this and how should I use these three pins? They are usually marked as (+) plus, (-) minus, and T.
adopilot
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Batteries. Why use 9V?

With all the technology available today with being able to boost voltage efficiently using SMPS, why do we still use 9V batteries? Is there some secret advantage with them that I am unaware of? If you look at the size as well, the 9V is just big…
MCG
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I am a quadriplegic. Would it be possible to power my ventilator humidifier with a battery?

I am an absolute novice in regards to electrical engineering, and so I am hopeful your expertise can guide me in the right direction. I know this is an unusual post for this forum, and so I thank you in advance for your consideration. First, let…
starbucksguy
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Does mAh measure how long a battery would last?

I know mAh tells how much milliamperes a battery can deliver in an hour. But does that also tell how many hours the battery would last? Sorry but I don't really get it. If we're talking about a water tank, to my impression, mAh is like how big the…
supertonsky
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How should I use a multimeter to determine which AA batteries to keep and which to toss?

I have a bag of about 50 non-rechargeable AA batteries (1.5 V) that I have collected over the years. I bought a multimeter recently and would like to know the best way to test these batteries to determine which ones I should keep and which I should…
LeopardSkinPillBoxHat
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Lightning bolt vs. batteries: a coulomb in everyday terms

I am trying to decide if the information on the wikipedia page http://en.wikipedia.org/wiki/Coulomb#In_everyday_terms is reasonable. In particular the statements that a lightning bolt has about 15 coulomb, where a battery has 5000. My first…
kasterma
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Can a 12V battery give you a shock or not?

I am reading a book called "Make: Electronics" and, on page 9, it says: "Anyone who has dropped an adjustable wrench across the bare terminals of a car battery will tell you that short circuits can be dramatic at a "mere" 12 volts, if the battery is…
Bitcoin Cash - ADA enthusiast
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When a battery is your power source, what is ground?

For the sake of not incorrectly connecting my power supply and damaging my board I'm going to ask a relatively dumb question. Is ground on my board the negative terminal on my battery? Explicitly should I connect the ground to the negative terminal…
QueueHammer
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Why do we connect a battery to ground when jumping a car?

This may seem like a very simple question, but I've searched all over the place and haven't found an answer. When jumping a car, we connect the + end of the charged battery to the + end of the dead battery, and the - end of the charged battery to…
Ken Levinski
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Regulated 3.3V from a Lithium-ion (or LiPo) battery

Background I wish to power my circuit with a Lithium-ion or LiPo battery (likely a battery with around 1000 mAh capacity). These batteries have a voltage that goes from 4.2V to 2.7V typically during their discharge cycle. My circuit (running at…
boardbite
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At what voltage is a NiMH battery empty?

I have a battery pack of NiMH batteries. It is ten cells with 1.2V, 4000mAh each, put together in series. So rated voltage is 12V. After charging, i.e. when the charging device says that it is finished, I measure 14.3V. When I now discharge, at…
Till B
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Why are car batteries still so heavy?

Back when I was a kid, car batteries used to be huge heavy lumps of plastic filled with lead and acid. They used to weigh almost as much as a mobile phone (slight exaggeration there, sorry). 45 years later, car batteries still look the same and…
user130311
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Are decoupling capacitors needed with battery power?

Currently I run all my gadgets from batteries and don't use decoupling capacitors. Are they generally needed/useful when drawing energy from a battery?
Mr. Hedgehog
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What is the truth about 1.5 V "lithium" cells?

At least one manufacturer out there is marketing "Lithium" cells in familiar AA and AAA sizes, as direct replacements for those standard 1.5 V sizes, boasting the typically better than alkaline longevity you'd expect from lithium. But we all know…
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