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
Can a circuit be both series and parallel? Not series-parallel, but series *and* parallel?
Let's say you have a battery with its positive terminal connected to a resistor and its negative terminal connected to the other end of the resistor.
Due to conservation of...
Hi,
So I have a question that I feel is best suited for people who know much about electricity and circuits. I have a 12V 7Ah sealed lead-acid battery (here, FYI http://www.parts-express.com/pe/showdetl.cfm?Partnumber=140-366).
I also have a small stereo amplifier, 12VDC 2A, that is...
Homework Statement
Hey, I know this is exteremely basic problem and the answer is "easy", but I can't
just get the exact idea why it's so.
"The starting motor of particular car has a resistance of 0,15 Ω and is powered by 12 V battery through a cable which has a resistance of 30 mΩ ...
Homework Statement
Capacitors C1=13μF and C2=21μF are each charged to 10V, then disconnected from the battery without changing the charge on the capacitor plates. The two capacitors are then connected in parallel, with the positive plate of C1 connected to the negative plate of C2 and vice...
Hello all.
Was wondering when I test for amps on my car's battery when sitting in my driveway why doesn't the car's electronics work when I hook up the battery via a serialized multimeter? The current should still, theoretically, go through the meter to the car's electrical system but it...
I have a booster pack that I think has a 12V battery inside. One of the typical ones you get at a hardware store with air compressor, booster cables, light etc. Anyway it is at least 7 years old. I recently tried jump starting someone's car with it but it wouldn't, I think I was able to in...
Battery issues in Automotive!
Hi guys,
I'm required to write an essay about development of 'Automotive Power', with particular reference to the Batteries.
So, I'm looking for some current issues on the batteries related to its development!
Any idea?!
Thanks
I'm confused about the relationship between the voltages of different power sources. Since a car battery is more powerful than an adapter and both are known to have output of 12 Volts, what can be said about how much power is consumed by the devices running on 12V?
Will the same amount of...
Homework Statement
A coil of inductance 0.5 H is connected to a 18V battery. Calculate the rate of growth of current?
Homework Equations
E=-L(dI/dt)
The Attempt at a Solution
Actually I have the solution but the problem is that in the book they have assumed that the back emf that would develop...
Hey. Was jump starting and charging a car battery a couple of days ago for the first time. I connected the positive of the bad battery to the positive of the good battery, then connected the negative of the good battery to a solid metallic, non-painted part of the engine on the bad car, or the...
I am from a country where power outage is very common.
I have a light source which is run by a lead acid battery. At night, I want to keep this light ON during power outage and when the electricity is back on, the charging circuit engages and the lights should turn off itself.
I am guessing an...
I studied mechanical engineering in college, so electrical engineering isn't my strongest suit. Basically I have a 12V car battery that I need to discharge to 70%, how can I do this?
I know that I can monitor the state of charge by determining the open circuit voltage after ~24 hours of...
I saw 15 Amp motor which runs on 120 VDC with 5500 rpm [This motor was attached to Miter Saw tool]. I'm not sure what's HP of that motor, but I read 5.5 HP, however the size of motor is around 6 inch long and 4 inch diameter (Is it possible this small motor have 5.5 Hp? And can we calculate...
Hello forum,
I have a ceiling fan with a remote control. The battery dies too quickly. There is only one IC in the little circuit board. I would like to understand where the issue is.
Can I do that with a voltmeter? But where would I look? What approach? Where would I measure the voltage to...
Surprised there hasn't been a thread for this big topic. Any experts out there want to weigh in on what the problem is, how it can be fixed and what this means for Boeing?
http://www.cnn.com/2013/01/24/travel/dreamliner-investigation/index.html?hpt=hp_t1
The infernal battery
http://news.yahoo.com/holds-energy-tech-back-infernal-battery-221338549--finance.html
So the next big thing will be a battery with a less flammable electrolyte and that is compatible with the Li ion system, unless something better than Li ion can be developed...
Hi just made a potato battery, using a cupper coin and zink nails (not connected in any way, just pit in a nail and 3 inches appart a penny), I was just wondering what is the chemistry/physics theory here?
Potatoes contain phosphoric acid
H3PO4
Is it the acid in potatoes that oxidize...
Homework Statement
We can't use anything else, and just have to make a logic circuit (either OR, AND or NOT) with just this material. We can use less or more diodes but I have only 5.
Homework Equations
The Attempt at a Solution
I tried setting it up like doides but no help at...
http://electronicdesign.com/site-files/electronicdesign.com/files/archive/electronicdesign.com/files/29/1823/figure_01.gif
So let me just start by saying that, I want to understand how to analyze circuits and I would like to find a good source for that. If some one could point to online...
I've been wondering how does this motor work (if it is not hoax in the first place)
I was thinking about Ampere's force but apparently it doesn't really have an affect here. Any ideas?
Hello,
I recently was thinking about an idea for a perpetual battery. I have an extremely limited amount of Physics knowledge (just a Conceptual Physics [Algebraic Physics] class) as I am still in high school. Does anyone know if this would work:
1. Have a tube
2. Wrap the tube in copper...
Hello,
I have seen graphs of Battery's DoD (depth of discharge) vs Life Cycles. But at the same time, "life cycle" is defined as the no. of COMPLETE charge-discharge cycles that a battery can perform before its nominal capacity falls below 80% of its initial rated capacity.
Here's the...
Battery "loaded down"?
Homework Statement
A current of 20 amperes is being drawn from a battery whose emf is 24 volts. The
internal resistance of the battery is 0.3 ohms. By how many volts is the battery "loaded
down"?
Homework Equations
V = IR
The Attempt at a Solution I...
Hello,
New here, sorry if this in the wrong thread.
I just finished a college general physics 2 course and in it we had an experiment where we passed a magnet through a coil of copper and a computer read what the induced emf was. This reminded me of a flashlight I have which uses the...
Hi,
I have a solar panel currently charging two 6V batteries after being sent through a solar regulator and was hoping to either monitor the battery levels or the voltage/current being output from the regulator. Was hoping to monitor this through a IOIO microprocessor that has analog inputs...
Hello,
I am trying to use a DC voltage sensing relay to control a generator in order to charge my batteries when they get low on charge. I have two 12 volt batteries in parallel connected to an UPS Inverter/Battery Charger. This charger is powered by the generator. I want to connect (in...
Homework Statement
Circuit as shown below.
At what voltage of E does the battery begin to charge?
What percentage of the power is delivered to the 1R resistor by the voltage supply E when the charging current is zero?
What is the current through the battery when E = 20V...
Homework Statement
A light bulb is rated at 3 watts when connected to a 6 volt battery. How much power will it dissipate if it is connected to a 12 volt battery?
Homework Equations
P = IV
The Attempt at a Solution
3w = I(6v)
I = 1/2
P = (1/2)(12v)
P = 6w.
Okay, so I heard...
Homework Statement
The diagram is of a circuit with 2 resistors in series (1 ohm and 2 ohms) connected to 2 batteries (a 9 V battery and a 12 V battery). The question asks, how much energy is provided by the 12-volt battery in 3 seconds?
Homework Equations
Power = IV = I^2R = V^2/R
I =...
How do I read such a chart?
http://www.showa-denko.com/fileadmin/template/img/SCMG_discharge_characteristic.png
It looks to me from this chart that available capacity increases while voltage decreases, but it is not what I see on my batteries: the more I use them, the lower their voltage...
Homework Statement
I'm having trouble figuring out where exactly the battery is and if it's connected in series or parallel when the diagrams are given like in the image below.
The book gives this description for the diagram. I don't really understand it.
In other words how can I...
Hello,
(1) Is the below equation for calculating the maximum velocity for attaining the alleged maximum distance correct, i.e. at what speed should an electric car travel for it to cover the maximum distance?
E of battery - (F rolling friction + F air drag)*(alleged maximum distance) =...
I reduced to equivalence capacitance and found the potential difference between the nodes based on what was provided using the rules of parallel and series and my final answer doesn't match the answer given. I have a test in two days and have been studying this along with other subjects. Could...
Hi Everyone,
I need to build a battery for a shoebox-sized vehicle.
I'm still collecting requirements, but I'm wondering if you have any suggestions beyond a potato battery ;^)
Farina
How long have you ran your car battery running on "lowest key position", just playing the radio.
How long do you think a 05 model should have it's battery last for this. Range?
:]
I read an article in prison inventions and was impressed by some of the things the inmates MacGyvered. A very simple invention I saw though was a cigarette lighter made from a battery:
I have an understanding of basic electronics theory but I have very little practical experience. I can see a...
How big of a battery would...
How big of a battery would it take to power the average sized home for 24 hours?
Considering basic kilowatt-hour consumption with AC. Would it even be possible to power a home off a DC source?
I would hypothesize that you would have to change all of your...
Hi,
I was just learning about Electric Vehicles, and how they are powered. Let us consider a BEV (Battery Electric Vehicle), and not a hybrid. So we just have the battery powering the drive train and the wheels.
The other day a friend of mine asked why the each wheel of the car can't in...
I have a LifeFitness exercise bike. It uses a Hawker Energy Sealed Lead Rechargeable Battery that is three cells with a rating of 6 volts at 2.5 AmpHours for 1019 Watts.
The battery is recharged by usage of the bike. However, the bike is designed for commercial use and the battery discharges...
Homework Statement
Find the current in the circuit and the voltage on the volt meter
Homework Equations
E=22.5 V
Rtot= 1kΩ + 2.4kΩ + 5.6kΩ = 9kΩ
I=U/R=22.5V/9kΩ=2.5mA
A voltmeter has super high resistance, to prevent any current from passing through it. I know that.
So I have...
Hi, I don't know so much about electronics but...
I know when you have a junction of two metals that is heated you can get a small voltage. Like wrapping a piece of wire around a nail and holding a flame over it produces a very small but measurable voltage. This is a thermocouple as far as...
HeyoO everyone (^_^) and Thanks for your time.
Homework Statement
This question is about the "intial" point of time i.e. as soon as the key is closed.
Before the current starts to flow which charges the capacitor till the voltage of capacitor is equal to voltage across the battery.
A...
I want to build a salt battery, and I've seen them use Zinc and Copper.
But what if I replaced Zinc with Tungsten, since it has an ion charge of 6+.
Would that increase the amount of ions, released into the water, and increase the power output? Do you have any suggestions for more potent...
I am wondering how can an alternator charge the battery if the rpm change constantly? Can someone please explain me how it manages to produce a constant voltage?
Hi! My brother has a small micro-heater that runs on a single AA battery. The battery life tends to be rather short so we started using rechargeable batteries. The rechargeable batteries are marked as 2000mAh and since they're AA and Nickel-metal Hydride I'm guessing they operate at 1.25v...