A battery is a power source consisting of one or more electrochemical cells with external connections for powering electrical devices such as flashlights, mobile phones, and electric cars. When a battery is supplying electric power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells, however the usage has evolved to include devices composed of a single cell.Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used for flashlights and a multitude of portable electronic devices. Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current; the original composition of the electrodes can be restored by reverse current. Examples include the lead-acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones.
Batteries come in many shapes and sizes, from miniature cells used to power hearing aids and wristwatches to small, thin cells used in smartphones, to large lead acid batteries or lithium-ion batteries in vehicles, and at the largest extreme, huge battery banks the size of rooms that provide standby or emergency power for telephone exchanges and computer data centers.
Batteries have much lower specific energy (energy per unit mass) than common fuels such as gasoline. In automobiles, this is somewhat offset by the higher efficiency of electric motors in converting electrical energy to mechanical work, compared to combustion engines.
Homework Statement
A dead battery is charged by connecting it to the live battery of another car with jumper cables. Assume that V = 5.5 V and R = 0.50 .
What is the current of the starter and the current of the dead battery?
Homework Equations
I=V/R, I1=I2+I3, basically Kirchoff's...
I'm not sure I'm providing enough information in order to get a meaningful reply, but I'll try anyway:
Lets say you have a regulator of some sort, with a LC filter on the output, and some sort of feedback loop with an unknown transient response (i.e. you lack info on the system's phase...
hey...
i just wanted to know how can i make my laptop battery last longer...
need info about charging ..
and any other tips about saving my battery
thanks in advance
I am looking for a pocket-sized external battery to work with a handheld DVR. The manufacturer does make an external battery pack, however the manufacturer of the device is located in Korea, and no US dealers sell it.
From the product manual, it states that the manufacturer's external battery...
Hey guys, I'm new to this forum and I've been meaning to start a project of my own. I want to create a homemade battery that gives me the highest voltage and current I can have using only two-three metals and an electrolytic solution. It can only be easily accessed metals, as I live in a city...
Homework Statement
A battery provides a continuous current of 9mA (.009A) for 40hrs (144,000sec). During that time the voltage drops from 1.5 to 1.0. Assume the drop is linear with time. How much energy does the battery deliver during this 40hr interval
Homework Equations
P=IV
The...
Hi, everyone.
I stumbled upon http://video.google.com/videoplay?docid=6491441475172785592#"
I can't quite figure out how it works, so I figured I'd throw it out to you all.
I got so far as to come to the conclusion that it has to do with a buildup of static electricity and that, since...
I attached a pic of what I am trying to do. Now if the alternator is 12V I can charge the 2 batteries on the right but I can't charge the battery on the left without taking the blue wire off. I have a 24V inverter that is 1500watt and was wondering what would happen to the battery on the left...
Homework Statement
each bulb in the circuit has a resistence of one ohm. how much power is drawn from the one volt battery?
to see the circuit diagram, click on this link:
it is problem 16 on page 123
To see the circuit diagram, go here:
http://www.lightandmatter.com/bk4c.pdf...
Homework Statement
A rechargeable flashlight battery is capable of deliverig 50mA for bout 90 hours. How much charge can it release at that rate? If the terminal voltage is 4 volts how much energy can the battery deliver?
Homework Equations
i=dq/dt
q=it
The Attempt at a Solution
my...
Homework Statement
A primary energy source is able to provide 0.7 Watts power in order to charge a mobile telephone battery pack. The telephone operates at 3.5 V, and the mobile telephone’s 3.5 V battery pack has a capacity of 1050mAh. In “talk” the mobile phone draws an average current...
Hi guys, this is my first thread, and I am not sure where I'm supposed to put this so I hope this is ok? if not, please tell me how and where i can move it to
Ok, just a simple question that i can't seem to find anywhere, what is the current which is given out by a car battery?
Thanks, Tinger
Need help - my brain is mush and the longer I look at it the more I don't understand it...can someone please tell me if this calculation is correct:
Homework Statement
A car is run for 400 hours per year, with a total mileage of 10,000 a year.
The car uses diesel and consumes 2,000...
Hi
If you are kind enough to answer this please bear in mind that I know next to no physics and I'm quite intimidated by the subject so please don't give me an intractable answer that I won't understand. Please feel free to answer as if you are talking to a nice but dim high school student...
So I know that when an electronic device powered by batteries is turned off, the batteries actually continue to move charge and will lose energy over time. I keep emergency flashlights in storage and I usually put one battery in them backwards so that a circuit is not completed. What I want to...
Homework Statement
The question itself doesn't make sense to me, it says to find emf but the answer box has V=
?
problem is an attachment.
Homework Equations
I=e/(r+R)
Ir+IR=emf
P=VI
The Attempt at a Solution
If it wants voltage that's simple P=I^2R P=V^2/R V=54.8V if...
Homework Statement
Why is it harder to start a battery in winter rather then summer?
Homework Equations
Nerst Equation
Ecell = Ecell - RT/zf(lnQ)
The Attempt at a Solution
Isn't the lead sulfate bettery unique such that the electroyte for the anode and cathode is the same...
I "stumbledupon" this article this morning.
A battery that used radioisotopes and is powered by the decay of the radioactive material. Sounds like it would work. Is this legit? If so it seems like a pretty serious innovation. I'm sure this battery if developed for the public would have a...
Hi,
firstly apologies for what might seem like a 'basic' question, but I've been trying to work this out for a while.
I have a sealed lead acid (SLA) battery - 6V 4AH. I would like to use this battery to power a 4V coil (for a display) - that is capable of (potentially) drawing the full...
hi
I want to design a 4 cell (16.8V) lithium ion battery charger. The normal chips available have built in buck (reall buck or synchronous buck) or at least control circuitry for buck with external mosfets. This is necessary as wall adapter/source input voltage are higher and unregulated...
Hello, I would like to start by saying that I know very little about nuclear decay, so please do not flame me if this is a silly question:
I am wondering if it is possible to generate enough potential to light an LED indefinitely using pure beta decay. Let's say the circuit consists of a...
My set up was simply putting two lead plates into a beaker of sulphuric acid, then connect the lead plates to a power supply. What is the reaction for charging and discharging the cell? All equations I could found contain lead (IV) oxide... Is the reactions of my set up differ from a real...
I'm designing a battery charger consisting of an LM317. The regulator will charge three batteries successively, for example, when battery 1 reaches a terminal voltage of 13.8, a voltage comparator will activate a relay that will switch on the second battery while switching off the switch for...
This is an old saying that always annoys me! People swear by it but I just don't see how it can be unless the theory has been distorted over the years. Could it be that just the coldness of the floor weakens the battery? As it goes if you put a car battery on a cement floor it will discharge...
What happens if re-chargable batteries are left too long on their chargers? is there a fire risk? do some of them such as the ones used for moble phones and chordless power tools have some sort of cut-off safety mechanism?
I have built these before, but have forgotten how I did it. I am making a battery box with four 12v batteries (7.5 Ah each). I will have only one pair of output terminals, one + and one -. Inside will be a switch to toggle between 12 and 24v. I do remember that in the 12v position all batteries...
What I am trying to do is replace my 12v 5Ah lead-acid battery with a 14.8v 6600mAh lithium ion battery. It powers a small fan belt. And for some reason I can't get the lithium battery to work. Can somebody tell me what I might be doing wrong, or if it will even work?
I'm trying to understand how I could use simple circuit analysis techniques to model a charging battery in the circuit attached. The battery connected only to a power supply will want to sink up to about 1A starting out then will transition downward quickly to about 200ma. Then it will fall off...
I put a AAA alkaline battery in my pocket and later detected warmth. I took the battery out of my pocket and it was very hot. The only other items that I had in my pocket were a few coins and a key ring with keys and one of these plastic security fobs. I can only presume that some kind of...
i found that this invention uses water and aluminum to make hydrogen in the most efficient way, uses only 1 kg aluminum for 600km for a 900kg vehicle. for more details click the link http://anon99.tripod.com/water_engine/index2.html
Is this technology a better solution for today's crisis. if...
I want to build a "Betavoltaic Battery"
A while ago I got a tritium keychain that will glow for 10 years, and since then I've gotten very interested in building a generator based on this. Originally I wanted to build a conventional RTG but apparently it is hard to find radioactive materials...
I have two plate capacitors serially connected in a circuit with a battey and a switch between the battery and one of the plate capacitors.
I have two situaions:
a) I charge the capacitors, cut the switch, and double the internal distance in one of the capacitors.
b) I charge the...
Just like the title, does battery capacity depend on internal resistance?
I know it does depend on the temperature and the chemical structure of the battery,
but does it also depend on internal resistance?
If so, how dependent are batteries on internal resistance?
Also, what is the...
Is there a difference between the mass of a battery cell which is charged and the one which is drained? If yes, is difference of the two values proportional to the total work done by the cell (including loss due to resistance), with c^2 as the proportionality constant?
Homework Statement
For the circuit shown, find the power dissipated by the 10.0 ohm resistor.
(as attached)
Homework Equations
P=IV=I2R=V2R
V=IR
The Attempt at a Solution
I really don't know where to start with this. I'm basically tied up in the fact that there are three...
Homework Statement
calculate the power dissipated by a resistor R connected to the battery when R = 2.4 ohm.
Homework Equations
I=V/R
The Attempt at a Solution
I found A of battery that given and put R value given to find P, however I cannot get a right answer.
What did I...
I have a 230 CAA car battery, and 2 solar panels in a parallel circuit (one is 15V, 300mA, 4.5W, the other is 15V, 125mA, 1.8W). I know that these are under optimal conditions, so please assume that they are. How long would it take to charge my car battery with these solar panels?
Homework Statement
Given the following circuit:
What is the actual voltage provided to the circuit by the non-ideal battery if the internal resistance r = 0.50 ohms and the internal emf is 9.0 volts?
A. 9.8 V
B. 8.5 V
C. 9.0 V
D. 8.4 V
E. 8.8 V
Homework...
Homework Statement
a generator of e.m.f 20V and internal resistance of 0.5 ohm is used to charge a car battery of emf 12V and internal resistance 0.10 ohm.They are connected in series together with a resistance R whose value is adjusted to give a charging current of 2.0A.
I was asked to...
I am designing an electric vehicle and choosing the batteries. For this i want to model some inefficiencys into the batteries. I came across the formulae T=C/I^n where
T=battery life
C = capacitence
I= current
n= Peukert's number
would 1.1 for n be ok for lithium ion, it seems to take quite...
I have an concept electric car, i calculated it will need 15,000 Wh stored in batterys to operate over its required range (100 miles) on a certain drive cycle.
I am attempting to work out how many batteries i need.
The motor it is powering has a voltage rating of 156 vDC specs here...
I have an concept electric car, i calculated it will need 15,000 Wh stored in batterys to operate over its required range (100 miles) on a certain drive cycle.
I am attempting to work out how many batteries i need
The motor it is powering has a voltage rating of 156 vDC specs here...
Hey all .. i happy to join this forum because of the amount of information that it has ..
In our city , the electricity cut down for long time may be 10 hours in a day ..
I want to make a device so i can convert the car battery voltage ( 12V DC) to (220V AC)
this device called Inverter .. i...
I want to make a simple home made battery. I am just starting to do experiments at home and I have read you can make a simple battery from coins like pennies and nickles. In between the coins would be a wet paper towel soaked in salt water which acts as the electrolyte between the two coins...
Hi!
I just registered as I have been wondering quite a while about a specific question that grew in my head while reading about electronics in school.
As I have learned voltage is a difference in potential. So if we have a 9V battery there is a difference of 9V between the two poles of the...
Homework Statement
How much energy must a 42 V battery expend to fully charge a 3.62x10-6 F and a 6.11x10-6 F capacitor when they are placed in parallel?
Homework Equations
capacitor in parallel therefore total capacitance is the sum...
The Attempt at a Solution
I thought that you...
I have a motor which i am planning on using in an electric vehicle i am designing.
http://www.azuredynamics.com/products/force-drive/documents/AC24_DMOC445ProductSheet.pdf
and want calculate the number and specs of batteries needed to run it.
I have the power demand from the motor at...
hi i am new to this forum. i want to use a battery that will run a dc motor, dc motor will run three phase ac generator through mechanical coupling and the three phase ac generator will produce out put, now two phases of the ac generator will b utlilized by the load and 1 phase will recharge the...