Is It Possible To Have A Dead Battery That Still Registers 12 Volts

Rik is an engineer who has held a range of marketing, technical support, and management roles. He is also a qualified teacher.

Welcome to your guide to the basics of electricity.

The four nigh bones physical quanities in electricity are:

• Voltage (5)
• Electric current (I)
• Resistance (R)
• Power (P)

Each of these quantities are measured using unlike units:

• Voltage is measured in volts (V)
• Electric current is measured in amps (A)
• Resistance is measured in ohms (Ω)
• Ability is measured in watts (W)

Electrical power, or the wattage of an electrical system, is e'er equal to the voltage multiplied past the current.

A arrangement of water pipes is ofttimes used as an illustration to help people understand how these units of electricity work together. In this analogy, voltage is equivalent to water pressure, electric current is equivalent to menstruation charge per unit and resistance is equivalent to pipe size.

In electrical applied science, there is a basic equation that explains how voltage, current and resistance chronicle. This equation, written below, is known as Ohm's police.

Ohm's Law

V = I 10 R

Ohm's police force states that voltage is equal to the electric current flowing in a excursion times the resistance of the circuit.

I way of agreement Ohm's law is to apply it to the imaginary plumbing arrangement we've employed as a representation of an electrical system.

Let'south say we have a tank of water attached to a hose. If we increase the force per unit area in the tank, more water will come out of the hose. Thus, if we increase the voltage in an electrical organisation, we will also increase the current.

If we make the bore of the hose smaller, resistance will increment, causing less h2o to come out of the hose. Thus, if we increment the resistance in an electrical system, nosotros will decrease the current.

With this cursory introduction of the workings of an electrical arrangement, let's spring into each of the units of electricity separately and learn most them in more detail.

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The epitome above depicts a simple electric excursion with a seedling, some wire, and a battery.

What Are Volts?

Volts are the base unit used to measure Voltage. One volt is defined equally the "deviation in electric potential betwixt two points of a conducting wire when an electrical current of one ampere dissipates 1 watt of ability between those points." The volt is named after the Italian physicist Alessandro Volta.

In our battery diagram above, the battery provides what is known equally a potential difference in an electrical excursion, or voltage. If nosotros go back to our h2o analogy, the battery is like a h2o pump that propels water through a piping. The pump increases the pressure in the piping, causing the water to catamenia.

In electrical engineering, nosotros telephone call this electrical pressure voltage and measure information technology in volts. A voltage of three volts can be written as 3V.

As the number of volts increases, the current increases too. But in gild for the current to flow, the electrical conductor or wire must loop back to the bombardment. If we pause the circuit, with a switch for example, then no electric current volition flow.

There are standard voltage outputs for everyday objects like batteries and household outlets. In the Usa, the standard voltage output for a household outlet is 120V. In Europe, the standard voltage output for a household outlet is 230V. Other standard voltage outputs are listed in the table beneath.

Common Voltages

Object	Voltage
Single-cell, rechargeable battery	1.2V
Single-cell, non-rechargeable battery	1.5V–1.56V
USB	5V
Motorcar bombardment	2.1V per cell
Electric vehicle battery	400V
Household outlet (Nippon)	100V
Household outlet (North America)	120V
Household outlet (Europe, Asia, Africa, Australia)	230V
Rapid transit tertiary rail	600V–750V
High-voltage electric power lines	110,000V
Lightning	100,000,000V

What Are Amps?

The ampere, oft shortened to "amp" or A, is the base unit of electric current in the International System of Units. It is named subsequently the French mathematician and physicist André-Marie Ampère, who is considered the begetter of electrodynamics.

Electricity consists of the flow of electrons through a conductor, for example, an electric wire or cable. Nosotros mensurate the rate of flow of electricity every bit an electric electric current (just as we think of the rate of flow of water in a river as the river current). The letter used to represent current in an equation is I.

Electrical current is measured in Amperes, shortened to Amps or only the letter A.

A current of 2 Amps tin be written as 2A. The bigger the current the more electricity is flowing.

The International System of Units (SI) defines amps equally follows:

"The ampere is that abiding current which, if maintained in two straight parallel conductors of space length, of negligible circular cross-section, and placed one metre apart in a vacuum, would produce between these conductors a force equal to two×10⁻⁷ newtons per metre of length."

Electric Current Sit-in (Video)

What Are Ohms?

Ohms are the base unit of resistance in an electrical system. The ohm is defined as "an electric resistance between two points of a conductor when a constant potential difference of one volt, applied to these points, produces in the usher a current of one ampere, the usher not existence the seat of any electromotive forcefulness." The ohm is named after the German language physicist Georg Simon Ohm.

Resistance is measured in ohms, or Ω (omega), for brusk. And so, 5 ohms tin can be written 5Ω.

In our battery diagram in a higher place, if we remove the bulb and reconnected the wire so the battery was short circuited, the wire and bombardment would become very hot and the bombardment would shortly be flat considering there would be most no resistance in the circuit. Without whatever resistance, a huge electrical current would flow until the battery was empty.

Once we add a bulb to the circuit, resistance is created. In that location is now a local "blockage" (or narrowing of the pipe, per our water pipe illustration) where the current experiences some resistance. This greatly reduces the current flowing in the excursion, so the energy in the battery is released more than slowly.

Equally the battery forces the current through the bulb, the battery's energy is released in the bulb in the grade of light and heat. In other words, the current carries stored energy from the battery to the bulb, where it is turned into light and heat energy.

The image above shows a light bulb as the master cause of electrical resistance.

What Are Watts?

A watt is the base unit of power in electrical systems. It can also exist used in mechanical systems. It measures how much energy is released per 2d in a system. In our battery diagram, the size of both the voltage and the current in the bulb determine how much free energy is released.

In the diagram in a higher place, the lite bulb would get brighter as the ability, measured in watts, increases.

We can calculate the power released in the bulb, and of the electrical system every bit a whole, by multiplying the voltage by the current. And then, to calculate watts, the following formula is used.

How to Calculate Watts

W = V * I

For example, a current of 2A flowing through a bulb with a voltage of 12V across information technology generates 24W of ability.

How to Calculate with Watts, Amps, Volts, and Ohms

If y'all want to do an electrical calculation involving voltage, current, resistance, or power, reference the formulae circle below. For instance, nosotros tin can calculate the ability in watts past referencing the yellow area in the circle.

This formulae circle is very useful for many electric engineering tasks. Keep information technology handy the adjacent time you are dealing with an electrical system.

Beneath are some instance equations that are solved using the formulae.

Example Equations

i. What is the current in an electric circuit with a voltage of 120V and 12Ω of resistance?

I = V/R

I = 120/12

I = 10A

The current in an electrical circuit with a voltage of 120V and 12Ω of resistance is 10A.

ii. What is the voltage beyond an electrical excursion with a current of 10A and 200Ω of resistance?

5 = I x R

V = ten x 200

V = 2000V

The current in an electrical system with 10A and 200Ω of resistance is 2000V.

three. What is the resistance in an electrical system with a voltage of 230V and a current of 5A?

R = Five/I

R = 230/v

R = 46Ω

The resistance in an electrical system with 230V and 50A is 46Ω.

Formulae circumvolve for solving electric unit of measurement equations.

In Determination

After reading this article, you lot hopefully have a better agreement of the difference between electrical electric current, voltage, resistance, and electrical power. Recall that if you know any 2 of the physical values in the formulae circumvolve then y'all can calculate each of the other ii unknown values.

Basic Electricity Tutorial (Video)

Electricity Quiz

For each question, choose the best reply. The answer central is beneath.

1. If I connect a 120V supply to a 60W bulb, what current would period in the excursion?
   • 1A
   • 2A
   • 0.5A
   • 5A
2. If a 3V battery is connected to a bulb and a current of 1.5A flows through it then what is the rating of the bulb?
   • 3W
   • 2W
   • 4.5W
   • 0.5W

Answer Central

1. 0.5A
2. 4.5W

Interpreting Your Score

If yous got 0 correct answers: Perhaps you demand to reread this article?

If yous got ane right answer: Do yous see where you went incorrect?

If you got 2 right answers: Well done. Y'all certainly know Watt is Watt!

Questions & Answers

Question: What is the resistance of the heating element of an electric atomic number 26 if the ampere draw is 8 amperes when 115 volts are applied?

Answer: R= V/I = 115/8 = 14.four Amps

Question: Can I run ii appliances at the aforementioned time when the max amps available is 5A? One requires 3 amp, and the other requires iv.15 amp.

Answer: The reply is no. The total current drawn is seven.15 Amps. This would overload a 5A socket, and result in a 5A fuse blowing or a 5A circuit billow existence triggered.

© 2009 Rik Ravado

Robert on May 26, 2020:

Very informative and helpful.

James Watt on Apr 23, 2020:

"and Watts are named after Scottish inventor and mathematician James Watt"

Dennis on April 09, 2020:

Very useful, insight

CR7 on March 24, 2020:

Blurry images

Rooprick on Nov 22, 2019:

I'one thousand trying to attach a cork to my Fork and so when I eat I don't hurt myself or others how do I do that

brit on November 21, 2019:

absurd

Branson on September 24, 2019:

I am trying to design a battery power led light strip. My question is if my led controller is 12v, what amperage 12v battery supply can I utilize? 2A? 4A? 6A?

remlalnghaka on September 21, 2019:

very interesting

Rahimullah Sahak on August 02, 2019:

hi dear thinks for your skillful and a best incarnation I accept ane question what is the spicefication of wire and his colour and his cade

ubaid on July 31, 2019:

how much units volition be comsumed by an electronic device of 3 amps per hour

manivannan on July 18, 2019:

thaks to all informations

Ghulab hameed on May 15, 2019:

sir plz tell me how we know a device how many voltage applied and which condination will be prove?

Krystal on May 14, 2019:

Trying to get the answer to this question can anybody help me please demand if by the moring for school

1. Question:

I=.5amps,R=50phms,P=

Heidy on Apr 01, 2019:

thank you for explaining the basics of electricity. It make sense now

Asitya on March twenty, 2019:

Squeamish information technology'due south so piece of cake

COOPER IS SIMPLE on Feb xi, 2019:

Cooper said he's being uncomplicated simply he's using highly unnecessary "big" words and it is stupidly simply abrasive.

robert cannon on January 21, 2019:

I don't care about small electrical quiz I what one question answered what gauge wire is needed to hook upwardly a welder rated at 230 volts 220 amps equally far as I got equally it is with electricity is this high a amperage will impale you lot

Aamir on January 17, 2019:

very well explained.

yoyo on Nov 05, 2018:

thanks !..it was interesting.

Cooper on October thirty, 2018:

Then we know plugging an extension into another extension (and having load existence fatigued from said setup) will (maybe) hit the maximum allowed Amperage/Wattage for that extension and fire it out...

But we can have multiple devices like Fridges, Freezers, Idiot box'due south, Irons, etc, etc... Each on their ain "Plug Socket" merely aren't the Plug Sockets substantially just 'extensions' of the house Mains? -

Presuming my reply is probably available on the house's Main Fuse Board?... I'm curious to enquire how one would calculate the Maximum Potential Amperage & Wattage load of one'south unabridged business firm!

I know I could add together up all my devices and summate 'My Specific Total Draw' but how much further 'til I hit the 'maximum for my residence'?

The respond is probably stupidly simple, merely I'm being stupidly simple at the moment then such an answer would exist warranted :D

- Cooper

Sanju pradhan on October 18, 2018:

It's very helpful to me for my studies.

Oh ya daddy on October 10, 2018:

Thanks helpful

Liam on Oct 05, 2018:

Very Interesting, thankyou!

hi infant on July 03, 2018:

very good and very helpful

Brunsrm on April 02, 2018:

Can I run ii appliances at the aforementioned time when the max electrical provided is five amps? One requires 4.12 A and the other requires 3 A.

Thank you for your help

Taylor on March 27, 2018:

I had to do a speech on inventions that changed the quality of life. I chose electricity. This website helped.

Prabhjot on March 17, 2018:

Thanks a lot for teaching us in easy ways so we could understand thanks :)

Hendrik on February 25, 2018:

Ω my god, 31 years old and finally sympathise the basics!

Gabe on February 23, 2018:

This make me empathize how does volts and wats work. Before i cant practice the difference between volts and watts.

I love Yucheng Jade Shao on Jan 23, 2018:

This was an amazing presentation and information technology helped me alot to sympathize volts, Amps, Ohms, and Watts!

David on January 15, 2018:

This is an splendid video that I highly recommend for all beginners like me. I now take a adept basic understanding of how electricity works in our everyday world. Thanks!

ramesh kumar verma on January 01, 2018:

pleas help me how understand electricity ie wattage, volts and amps, how to increase amps & subtract in the circuit

a random guy on Dec 15, 2017:

a skele-TON of information, cheers.

a random guy on December xv, 2017:

this helped a lot

toby on Nov 10, 2017:

Examples used in teaching were the best i read so far.Thank you and then much :)

Esmaeel on October 30, 2017:

It'due south really an added value

zulfiqar Ahmad on Oct 25, 2017:

Very dainty

S Kanda on October 21, 2017:

It helped me to understand electricity ie wattage, volts and amps, amend than books.

D.bell on October 04, 2017:

This helped a lot thank you

mehul lavri on September 26, 2017:

practiced presentation

asif javed on September 12, 2017:

brilliant description about electricity

J. R. on September 08, 2017:

Very good presentation

andrea Sherman on September 04, 2017:

I never understood how that worked. I notwithstanding am sort of dislocated . isn't electricity measured in both particles and linear?. I took a grade called physics for poets well-nigh 40 years ago. cheers✌

@Jeet on August 29, 2017:

Very useful thanks.

Meseret Yirdaw on May 25, 2017:

That is very overnice.I would like to give thanks more and more.Keep it up.

Ashfaq on May 24, 2017:

Very helpful page regarding empathize of uncomplicated electricity

Harpal Singh on May 15, 2017:

Amazing.....Honestly speaking this is the first fourth dimension i fully understood it...

thks....

kira on May 03, 2017:

i really find it interesting while reading this,and I learnt alot,thank you anybody for contributing to this.

Chethan shetty on April 13, 2017:

Helps to empathize even for mechanical students

Sandip Deb gupta on March 23, 2017:

Information technology'southward very good article wonderful experience

Nope on March 08, 2017:

Thank you

Rizwan on January 22, 2017:

Dainty caption

DILLI SAHU on January 22, 2017:

Thanks Sir,

Squeamish due north simple explanation of electric current, volt and watt.

lavysay on January 05, 2017:

cool

Nancy Marine on October 03, 2016:

I got 2/2 of the question, I guess I know watt is watt.

ade on Oct 03, 2016:

amazing, never been able to get this stuff in my Head and you've managed information technology so succinctly mate, thanks always so much, Cheers

jeo on September 16, 2016:

hi there, i am just getting to know nearly electricity. and has always been confused to hell, what is Amps, Volts etc. now i understood it all.

thanks for the article. God Bless

SAQIB from HYDERABAD PAKISTAN on January 29, 2015:

Existence engineer myself I enjoyed reading the concepts.

sanjay on December 19, 2014:

Very good

MARJ WATSON on July 26, 2014:

Delight advise this quondam lady if I can utilize Gu10 replacement bulbs with 110/220 in the great britain, as I bought them in fault, thanking yous in anticipation,

Marj

Someone on March 08, 2014:

That was useful thanks

santosh kumar on January 20, 2014:

Thanks a lot for your wonderful detail explainatin. I hope it would be very helpful to all beginers. Best wishes for your blog.

Alpo on January 05, 2014:

Thanks for the tutorial...it has been awhile and was looking for the basic equations. According to your commodity, "A" is short for amperes or amps. Later, "I" is introduced without relating it to amps. For clarity, you might add together that.

vikas pal on September x, 2013:

great blog

Alex on May 22, 2013:

Can someone help to find out 12 volt ??? w required in the given satiation?

I required 220 volt 1000 w to run my application. i am planning to install solar panel to have full fill my requirement. it involve solar panel ,12 volt battery, and ability inverter, how many watts of 12 volt panel practice i required to take 220 volt 1000w power to run my application

Rusty on April 09, 2013:

I found it interesting that elkangorito said no way 120 is safer than 230 volts. Then why in England on ALL commercial work sites the max voltage used is 120? Everything is stepped down from 230 to 120.

Cheers

Kiran Chandran on October 04, 2012:

I had cleared many doubts past using this........

amped on July 17, 2012:

Very useful explanation.

saratchandra on May 25, 2012:

Good explanation with examples

ajay on Apr 16, 2012:

thanks for the answer. sir delight give 1 more than answer about transformers. I read somewhere that transformers tin can increase and decrease the voltage of a said line, so in that case is it possible to decrease the incomming 220v chief line of my business firm to say 24v and then again increment information technology 220v for normal usage. will the functioning be the same and will information technology decrease the electric bill.

Rik Ravado (author) from England on Apr 14, 2012:

ajay - the maximum electric current would depend on the fuse or breaker in the excursion. In theory, if y'all short circuited the 120v yous could get an space current but domestic supplies normally have a breaker that trips if you draw besides much current. In the Britain, our domestic circuits typically permit yous to draw about 13A from a three pin plug but it my be higher elsewhere, for case the US.

ajay on April 14, 2012:

how practice we decide the maximum limit of ampereage that can be drawn out of a 120 volts line

Ak on Dec 28, 2011:

Thanks for the heads-up Rik. I desire to implement inexpensive renewable energy, could you outline few options? Pv or solar panels are not the options where i live. I heard a lot almost fuel cells, are they expensive?

Rik Ravado (writer) from England on December 22, 2011:

Ak - These products are all scams. You don't become electrical energy for aught. You can convert mechanical energy into electrical free energy, a generator does this. But you still have to put the same amount of energy in. Scammers sometimes talk nigh perpetual motility in connexion with gratuitous energy simply information technology doesn't be.

Ak on December 21, 2011:

I accept a question.. Can the magnetic energy be converted to electrical enegergy somehow by properly placing them on a flywheel? Rotating the flywheel using the magnetic forcefulness. There are lot of things going on the web nigh it. And how come they only sell guides just not the finished production.

Ak on December 21, 2011:

Clear as crystal

Robert on December xviii, 2011:

First, give thanks you does non say plenty for this. I am a tiresome learner and forward to using this to help acquire most electricity. I am finding out that it is non that hard, but like Bert One thousand commented, U+P=R. Thank you again so much Mr. Ravado

Rik Ravado (author) from England on November eleven, 2011:

Brett

Well spotted - I agree. (Changed the graphic) Thanks!

Brett on Nov 10, 2011:

Shouldn't your graphic read I = sqrt(P) / R instead of I = sqrt(P) / V?

Rik Ravado (author) from England on March 12, 2011:

Thanks for the feedback Bert - you are so correct with U+P=R.

Learning is much more constructive when yous put what you have learned into practice!

bert 1000 on March 12, 2011:

cheers for the free lesson. you made it very clear and piece of cake to understand. here is a smart formula i'd like to laissez passer on to beginners like myself. U+P=R or utilization plus exercise equals retention. i wish there had been cyberspace and google when i was a kid. best regards teach. bk

topquark from UK on February 07, 2011:

Useful and well-presented article! A lot of people seem to go confused about Watts and Amps and Volts - an explanation like this has been long overdue.

bernie on October 12, 2010:

Everyones a cridic. I understood completely and I understood that information technology is not on the money, and those of us who don't have to act like know it all's realize that there are factors involved that makes the math close, merely there is room for error. Peradventure thicknees of the wire existence used, battery losing ability, or any the reason. People chill!!! If I understood and realise this so you lot encephalon childeren should. Anal Bastards.

Kevin on October 03, 2010:

Thank you for this mate.

Helped a lot with my schoolwork. :P

Rik Ravado (writer) from England on June 09, 2010:

Thanks Peter!

Peter Enmore on June 08, 2010:

Yeah, you really can't get the calculation it to an exact. But you can definitely get an approximate.

Rik Ravado (author) from England on Feb 06, 2010:

Elk

Thanks for your comments - I still maintain 120v is safer than 230v. In other words the lower the voltage, the less current potentially flows through the victim.

I concur with your 'approximately' every bit apparently cablevision and other elements in the circuit will further lower the electric current. As well the rating of the bulb or other appliance will not exist precise and in that location volition be a margin of mistake.

Thank you for stopping past and commenting!

elkangorito from Thailand on February 06, 2010:

Fifty-fifty though your weblog is an excellent "guide to the basics of electricity", there are a couple of things that need to be considered:

You said, "In the Us, the domestic supply is typically 110V, much safer than the United kingdom of great britain and northern ireland."

This is non true.

Firstly, the voltage in the UK is officially 230v (single phase, domestic).

Secondly, the voltage in the U.s.a. is 120v (domestic).

120v is in no way "safer" than 230v. A "safety" voltage is considered to exist less than 50v RMS (Air-conditioning) or 120v DC (ripple gratis). These voltages are known every bit "extra depression voltages" & relate to "touch voltage limits".

You too said: "Finally, retrieve that if you know the voltage of your power supply then you tin can summate the current through a bulb, fuse or other electric appliance or component, based on its rating in Watts."

I think that y'all meant to say, "Finally, remember that if you know the voltage of your ability supply so you lot can APPROXIMATELY calculate the current through a bulb, fuse or other electric appliance or component, based on its rating in Watts."

Rik Ravado (author) from England on November 04, 2009:

LiamBean - glad you establish information technology helpful!

LiamBean from Los Angeles, Calilfornia on October 23, 2009:

Lovely. Wonderful explanation of Watts, Amps, and Electric current.

Source: https://owlcation.com/stem/Watt-are-Amps-and-Volts

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