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.
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...
I'm thinking about all types of charging (LiIon, lead acid, etc.). I get the basics...but would really enjoy more info on the subject.
Also...one thing that confuses me is how you can "overcharge" a battery...and how you can supply too much current (amps) to the battery. Since its generally...
Say you have a battery 100ah and you want to charge it the fastest way.
What's better? if you have a solar panel 12v 100w or a solar panel 24v 100w
(all at the same amperage rating).
I thought the 12v 100w, but a friend is telling something about the "ohm law", which I don't know. Could...
So a battery to one of my phones got left in the car (just the battery) for an extended period of time during a Texas summer.
The sides of the battery expanded by a couple millimeters. But I can compress the sides with my fingers as if there was a pocket of air in between the outer tape (with...
Just a bit confused & I am in need of a simple explanation of how energy flows in a battery. This was my thinking:
Cathode: positive terminal, current flows OUT
Anode: negative terminal, current flows IN
Is this correct? And if so, why do many battery diagrams depict energy flowing out...
Hi all,
I've been trying to find some sort of multimeter/voltmeter/etc that will allow me to get an accurate (and independent of the handset) read on state of charge, or remaining life, on a standard cell phone li-ion battery.
I've found a few voltmeters and the like, but my understanding...
What I'm asking is not strike and dissipate, I'm asking really capturing and storing the energy for later use. I mean are we talking more than cubic kilometers?
I know a thunderbolt is just regular, really high power DC but if 220V@10,000W can be bottled in a less-than-half-a m³ UPS, why is...
Hi
I'm working on a way of connecting prismatic LiFePo4 pouch cells into a battery pack.
I'll probably use G10/FR4 for the isolators, as suggested by MQuack in the Mechanical section of this forum, see this animation (the green parts are the FR4...
Hi to all, I have generator 3500watts (Made in China). it has pull start with rope. and i want alternate start with self start...! i hope you understand what i am talking about. Thanks in advance.
what accessories or tools required?
how to do?
how it works?
guys i am not engineer...
Hi All
Currently studying for a Subject Enhancement Course prior to starting a PGCE and I am struggling with the Electricity side of things! Something I also struggled with at A-Levels myself many years ago...
My query is how does batteries work. I understand the model whereby electrons...
Dear Experts
As a rechargeable battery , say a li-po battery, is being charged to near charging voltage, there is less potential difference which in this sense means it takes longer and longer to reach remaining few 0.x volts.
Could you be so kind as to explain a bit how a typical charger...
I keep hearing about new and more efficient batteries.
Is there a hard limit on the amount of energy that could be extracted from a stored chemical energy source?
Obviously the absolute maximum amount of energy would be given by E = mc^2, but I think that would be far beyond any...
Hi
I was just on vacation and forgot my camera's battery charger. I thought a lot about building some sort of homemade charger, but just didn't dare try. Luckily it ran out on the very last day, but I'd like to know if it would've worked.
Basically, the camera has a 7.4V Li-ion battery, which...
Hi all.
I planning to build an electric car at home. I have no expierence with electric vehicles but I studied physics at high school and know a fair amount about cars. After seeing homebuilt electric cars on you tube and elswhere I've been inspired to try bulid one also. I am going to try...
1. A 9 volt battery is hooked up to two resistors in series. One has a resistance of 5 ohms, and the other has a resistance of 10 ohms. Several locations along the circuit are marked with letters, as shown above. If the voltage is zero at the negative terminal of the battery, the voltage at...
Dear Experts
Lets say I have a power source of 9 volts.
A 5v output voltage regulator is connected to this power supply.
So, input 9 volts, output is regulated to 5volts constant.
the output pin is connected to a battery with has a constant internal resistance.
Does this mean, because...
I was looking at the simple example of making a voltaic pile using pennies, nickles, and salt soaked paper towels to light up a small LED lamp, but I hate the idea of immediately oxidizing all the metals just get a 1.2 volts for a only a couple hours so I've been researching ways to make it...
This may be in the 'you were afraid to ask' category.
There are many devices which work on batteries or alternatively when plugged into the mains. You can recharge the batteries. Obviously when you are using batteries alone they have to have been charged.
Now I am finding that while some...
I'm looking at custom building a Li+ battery pack, six or seven cells, and want to design a battery monitoring circuit that measures voltage of each cell and keeps track of charge/discharge. The battery pack needs to fit in a form size of about 8" by 2" by 2" so my circuit should be fairly...
So far I've been studying chemical engineering and it is mostly applicable. I'm not sure which classes I should be taking, though, and whether ChemE is even the best program to study within.
Ideas?
Hi,
This may sound a little silly but I have a circuit with 1 resistor which is a 1k ohm resistor
and is connected to a 9 Volt battery.I found the amps using ohm's law I = E/R which equals 9 amps.I have also used a multi-meter to see the resistance and I'm a bit confused a resistor is...
Hi,
I have simple question:
In small OFF GRID wind turbine systems, it is worth to continuously charge & discharge 12V Lead Acid Batteries? this means that we want that our loads (lights, Fans e.t.c) are 24hours taking power from wind turbine & batteries will continuously charge &...
I've been reading a lot about solar power recently and far greater uses that could be unlocked if we only had a viable way of storing the energy. I've encountered the fact that no battery as yet comes close to rivaling liquid fuels for as energy as well as research pursuing artificial...
I have a physics book that describes a battery in a circuit as like a pump that provided energy to the charge (e.g. a 1.5 volt battery gives 1.5 joules of energy to each coulomb of charge).
Am I right in assuming that the energy in a circuit is directly derived from the chemical/electrical...
We want to implement a fuel gauge into one of our field testing equipment.
The batteries are Alkaline type. Is there any proven method to calculate the amount of usable charge left?
Thanks in Advance
Prathap Chandra
I really want to do research in battery after I finish my undergraduate engineering course. which engineering course should I choose so that I am well prepared to do research in battery? (mechanical engineering, electrical engineering, chemical engineering) Thank you.
Has anyone heard of a feature whereby display processing power is linked to system power levels ?eg.: if you're operating on battery rather than wall plug, can that have an effect on whether you get full acceleration when watching videos?
My sister claims that, on her Mac, when the battery is...
Homework Statement
The circuit shown in the figure below is connected for 2.10 min. (Assume R1 = 6.00 Ω, R2 = 1.60 Ω, and V = 16.0 V.)
(a) Determine the current in each branch of the circuit. *already did*
(b) Find the energy delivered by each battery.
(c) Find the energy delivered...
Hi all, I am a new guy to the forum, glad to meet you all. iv been doing a little rc project and now need to wire up some lights. iv never done circuit work before but I am willing to gain knowledge on how to.
the main problem is that no matter how much i read or calculate, i cannot work out...
My car has a problem that there is some sort of load on the battery even when the engine is off. So the battery slowly drains with time. If left for more than a couple of weeks, the battery will be too drained to start the car.
I had this happen to me, and so I bought a mobile booster pack...
I have an Led with the following specifications:
3-3.2 V
Size (mm) : 5mm
Lens Color : Water Clear
Reverse Current (uA) : <=30
Life Rating : 100,000 Hours
Viewing Angle : 140 Degrees
Absolute Maximum Ratings (Ta=25°C)
Max Power Dissipation : 80mw
Max Continuous Forward Current : 24mA
Max Peak...
I don't know what happened.I changed a ravpower laptop battery for my DELL laptop for almost one year and now if the battery shows full electronic capacity,but it will power off after 5-30 minutes without any warning and cann't start any more.Then I pluged on the adapter,the laptop shows the...
I want to charge up a 12 volt car battery with an AC voltage passing thru a full wave bridge diode and I want my LED to be on when current is being supplied to the battery terminal and if circuit stops producing current for any reason LED will be off and not on as if it where receiving current...
Hi everyone!
I basically understand how the materials used in the chemical reaction of a battery work but now I want to know why some batteries have different ratings of voltage.
From what I've read, this depends on the materials that are used. What does it mean for some materials to do...
Hi everyone,
I've been reading about electricity lately and I've run into a question that has been bugging me for a while. If you have (or made) a battery that has a rating of 2 volts (this can really be anything, I'm just giving an example) and you wanted to increase it to 3 volts, how would...
electric go kart conversion. battery question!?
hi no idea if I've posted this in the right section, but i apologise now if it is, I've decided to do some tinkering with my retired kart basically I am pulling out the honda gx160 engine from my Honda pro kart and want to fit it with a "36v...
I have a battery. I can go get a screwdriver from the garage and open it to see the specs on it, but was for an electric bike. I don't have the AC adapter charger any more. Can I charge it with a universal AC adapter I have, just wired together? The AC adapter has two holes in the tip, and I...
Hi guys,
I'm interested in developing a small gps receiver that I can fit into a certain object so that when it gets stolen I can send a text to it, find the coordinates and track it. The sixe of space for the gps device to sit in would be approx ∅30mm, length is not an issue.
I am not an...
Guess its pretty simple-
Case1-
I connect a bulb of less power to a battery of voltage, say 1.5volts.
Case2-
I connect a bulb of more power to another battery of same voltage, say 1.5volts.
What is difference seen in the two cases? :
• will the battery drainout quicker in case2...
there are some computer related gadgets out there which, courtesy of the OEM decisions, have to be used with a small battery. E.g. some of the graphics tablet related pens are that way. Perhaps in some situations (like "battery prices just went up by 1000%" situation) it might be nice to be able...
A graduate student is trying to develop a flow battery based on aqueous solutions of 1 M Cu2(SO4) and Fe(SO4) (recall that the sulfate is divalent, e.g. (SO4)-2 and assume complete solubility).
Given a chart like this : CHART
How would I know that I need to select Copper (I) and Iron (II)...
Homework Statement
A 12V battery has an internal resistance of 6Ω.
a) If this battery is connected to a 10Ω load, calculate the power dissipated by the load.
b) Draw a graph showing how the terminal voltage of the battery and the current it can supply vary with load.
c) Derive a value...
Homework Statement
Connect a battery to a solenoid
A cylindrical solenoid 40 cm long with a radius of 8 mm has 250 tightly-wound turns of wire uniformly distributed along its length (see the figure). Around the middle of the solenoid is a two-turn rectangular loop 3 cm by 2 cm made of...
Homework Statement
A loop of wire is connected to the terminals of a battery.
See Diagram: http://www.webassign.net/walker/22-35.gif
The A terminal is of higher voltage, so the current travels clockwise from A to B through the loop.
If you have the ability to send whatever current you like...
A 3v battery is connected to a capacitor and 2 light bulbs all in parallel set up
1. Where is the total voltage drop at t = 0
2. Where is the total voltage drop at t = infinity
3. Which light bulb is brighter?
From my understanding, since this is in parallel set up at t = 0 the voltage...
My son pulled the wires off of the charging plug for his motorcycle (mini-bike).
I can use a Fluke to determine what side is positive comming from the charger, and trace the positive side from the battery to the charging socket.
My question is when charging do I connect the positive side of...