Battery Definition and 1000 Threads

1. Consider the group of resistors in the figure, where R1 = 12.3 and R2 = 7.95http://www.webassign.net/images/omegacap.gif. The current flowing through the 7.95[PLAIN]http://www.webassign.net/images/omegacap.gif resistor is 1.22 A. What is the voltage of the batter...

Why do Acetic Acid Battery power devices only for short periods of time? Does it have to do with Capacitance?

Hello everyone from the Physics Forums, I'm doing a school project and I'm looking for a potential anode alloy that is ferromagnetic which I could use with a copper cathode. I'm making a battery and I have to use copper as my cathode mainly because I have made the cathode cells structured...

how to design a bms circuit for nimh. we have 11 cells in one battery pack and and all the cells are in series, if one cell discharge rapidly then how to moniter it through controller?

So I have been wanting to build a Tesla Coil for a while now, and I did not want to make a large one, just enough for a 4 or 5 inch spark. That being said I began searching the internet for designs when I stumbled upon the 12 volt battery variation. The idea is that the 12v battery would drive...

How does a battery charge while it is operating? Just out of curiosity. I cannot figure out how this could possibly work if charge must travel from anode to cathode in order to operate the device, but must travel the opposite direction in order to recharge.

This is a list of ferromagnetic materials that I've found on Wikipedia's category ferromagnetic materials page. I was wondering which of these materials would make possibly great cathodes for aluminum anode in the application of creating an sulfuric solution based acid battery. The battery I...

My question is why is the energy stored in a capacitance equals to half the energy supplied by the battery. I already know that there is heat loss in wires. But what I really want to know is that why is it only half of it ? It could have been any other fraction.

Homework Statement For the circuit shown, the ##\varepsilon## has negligible resistance. Initially the capacitor is uncharged and the switch S is in position 1. The switch is then moved to position 2, so that the capacitor begins to charge. Given: [R, C, E] Find: The energy given to the...

Homework Statement Hello. I just need someone to check if I'm approaching the problem correctly (the steps I've taken are given below). I drew a quick sketch of the circuit here: http://i.imgur.com/mClttXn.png?1 In the problem, I am given the capacitances of A, B, and C. I am also given the...

Homework Statement I'm an introductory electromagnetism course and in lab we were observing how an electric current could deflect a compass needle. however, i also noticed that the batter itself (with no wire attached, so no current) could also deflect the needle. (for ex, if you brought the...

Homework Statement [/B] A 1.5 volt battery is short-circuited by a 2–meter long wire having a resistance of 0.02 ohm per meter. How large is the current flowing through the wire (before the wire or the battery burn out)? Homework Equations Voltage = Ampere x Resistance Ampere =...

Homework Statement For an ideal battery (r = 0 Ω) closing the switch in the figure below does not affect the brightness of bulb A. In practice, bulb A dims just a little when the switch closes. To see why, assume that the 1.5 V battery has an internal resistance r = 0.44Ω and that the...

Homework Statement I'm working my way through MIT 8.02x, the intro E&M course, on EdX. In Homework 3/Problem 3, we insert a dielectric between plates in a capacitor that is connected to a battery supplying potential V. So the charge on the capacitor increases by Q. How much work is done by...

How can current source be implemented? I think the source of current is the battery itself (due to potential difference). Plus current source has its own symbol. If battery is the source of current then does current source refer to the battery?

Say you have to power a simple motor with a solar panel, but that panel does not always supply the necessary power. What is the simplest circuit that could combine a DC motor, Solar panel and battery backup to ensure that the motor will continue running even when the solar panel cannot supply power?

1) I don't understand why current flows, for example when you have a source, it has 2 poles, + and -: then the electron should go towards +, if it's in the position 'D', it should just be stuck -- my theory is that because the electron that's in 'A' "enters the battery", so the battery has...

Trying to get my head around some ideas about "rechargeable" batteries and getting in a muddle! So I get the idea that rechargeable is a rubbish word for them but I have 2 questions: 1) Does heat loss (i.e. from bulbs) in a DC circuit result in eventual lower PD across a cell? Thinking in...

I have an older Win 7 laptop that I put it away for 2 months. I power it up lately, few things gone wrong. The computer said my battery died and have 0 charge even though I have it plugged in for over a day. Whenever I unplug the power, the computer just shut down completely. It's very hard...

I am planning to use the Panasonic NCR-18650 cylindrical cells for a BEV (Battery Electrical Vehicle). As it would be easier to buy ready-made modules, I have found a supplier selling a Li-ion pack that delivers 417 Wh(or in other words 11.6 Ah) at 36 V (something like what this guy uses...

If we boost voltage from 3.7v to 12v, is this will affect on watt we consumption from the battery or make your battery discharge faster?

Hello I need a source to power ADSL router when the electric power would be cut for any reason because i need to keep my laptop that i use for work connected to the internet. I found this "Anker® 2nd Gen Astro Pro2 20000mAh 4-Port Aluminum Portable External Battery Charger with 9V/12V...

Please if we charge battery with high voltage like the battery charge voltage 4.2v and we supply 5v, is that will reduce the battery life. Thank you

Hi guys, I'm Chris from Germany. First of all, I'm not an expert in science, biology or electrical engineering. But i would have this question to experts, that's why I'm here. Sorry if my question will sound "dumb" or "easy" but as i said, i don't have any knowledge in this field. Is it...

Homework Statement Why is the formula for internal resistance for a charging battery v = e + Ir? When the battery is supplying I to the circuit I understand why the terminal voltage, V, equals emf - IR (voltage lost by internal resistance), but if a battery is charging, why is the...

I don't understant how the positive electrode can attract both electrons and the positive Li ions as they both flow to it. Also, the way to start the whole process is to let the electrons flow, right? (Close the circuit.) Without it, the ions also don't want to start flowing, although there is...

So I am in the process of building various solenoids for some projects I have. But the issue I have is that the battery I use is over heating. From my understanding, when I connect a circuit to a battery, the energy gets dumped very quickly and overheats the cell. Is there a way to calculate how...

Hi every one, I placed a multimeter probe across the terminals of a 1.5 v alkaline battery and saw 2 M Ohms, I did the same across a mV power supply at 1.5 volts and got little below 1.5 K ohms. I don't understand what makes them have diffrent resistance, and exactly why? I did this because I...

Hi guys, I am working on a school project. I have an inclined cart mounted on rails moved by a winch. I would like to install an alternator on one of the cart axis, so I can charge a 12V car battery - 20Ah. The wheel turns at 12 RPM. At that speed the alternator will not work, so I am also...

We have a battery operated chair lift for seniors at our church. I am looking to replace the on board batteries with a DC power supply. The unit has 2 small 12 volt batteries in series to provide 24Vdc to power the chair. The motor is a 24Vdc 4 amp motor. I had put in a 24Vdc 200 watt power...

In the Princeton Review Cracking the AP Physics C Exam 2011 Edition book on example 11.9's solution, one of the batteries' terminals are swapped (the battery with 10V). I am not sure why the author's do this considering the current is drawn the same. Later on in the solution, they recognize...

Hello everyone! I'm working on my practical project in college and it's roughly about ''air battery'' (CAES) which is filled with help of solar cell (eventually I need to build small version of it). My mentor explained it to me roughly as well and I would love some help as I'm not very good at...

Hello i have a noobquestion: does a polymer ion battery lose capacity faster when charged and discharged at the same time??

What happens if a battery cannot supply enough current? Let's say we're using a 10V battery capable of supplying 1A of current. A single resistor is then connected so that the current is flowing through it. Using V=IR, if the resistance is 10 Ohms, current is 1A. What if the...

Hi I need a circuit to charge 4 aa lithium ion batteries. I need it to charge at 5 volts and when the batteries are done charging, the circuit cuts off. It would help a lot if I could get this in a small space around 2 quarter's. Thank You.

How does a battery creates a potential difference and what is the intuative way to look at potential difference when studying capacitance

What would happen if you took a battery into space? Would a current flow between terminals being it's in the vacuum of space?

So supposedly if you leave your phone plugged into a charger but the charger is not pluged into anything then it will discharge your phone faster, so if the charger cases have a charger connector constantly in your phone will it actually discharge it?

Dear Friends Is there a good battery capacity measurement device you can recommend? I need to measure how much capacity a lithium pack really has. Thanks. regards Ramone

Hi.. I am working as a signalling engineer in Railways. This weekend i am going to give a presentation on super capacitors and their use in railway systems. Most importantly i am going to show how we can replace batteries with super capacitors (EDLC). The problem i am facing is i don't have any...

Homework Statement Two parallel plates, each having area A = 3558 cm2 are connected to the terminals of a battery of voltage Vb = 6 V as shown. The plates are separated by a distance d = 0.54 cm. 1) What is Q the charge on the top plate? 3.5*10^-9 C 2) What is U, the energy stored in...

My question is simple: Why do batteries need electrolytes? Wouldn't the battery need the charge to flow only through the circuit in the device being powered? The point of the anode and cathode's separation is to preserve the potential difference, so why allow charge to flow through an electrolyte?

how much energy is gained by an electron in a battery?

There is an amount of energy stored in the battery. However, the rate of output would depend on the system its powering. What is the best formula to calculate the output energy from a battery? Also, what formula would calculate the stored energy of the battery?

Does a dead 1.2V rechargeable AA NiCad battery act as an open or closed circuit? My electric toothbrush's rechargeable battery recently died and the manufacturer expects me to replace the entire unit. Personally, I think that's a waste of money so I've already opened it up and I can see the...

Circuit Analysis -- Resistors and a battery Homework Statement Hello, if you see the attached I am trying to find the current I4.My plan was to find Voltage across R4 and use Ohm's law. Homework Equations V=IR The Attempt at a Solution I have simplified the circuit down(attached pic), I...

There is this voltage source that generates different types(piezoelectric device, the pressures exerted are not the same everytime), it is not a sine wave properly(A), then passing it to a full bridge rectifier, the outcome is like B, then you use a smoothing capacitor and the outcome is like C...

http://i.imgur.com/qsZ0PM4.jpg I opened up the back of the calculator to see what kind of battery I might have to replace eventually, but I didn't expect to see a second battery slot. Is it a backup battery slot? If so, how do I tell what kind of battery fits in there? I checked the manual...

NEVER MIND! I realized my question is kind of stupid. Its night here and I am kind of sleepy. :)) Homework Statement a battery of 4V is connected opposite to a battery of 2V to charge the 2V battery. assume the current running through the circuit to be 2 Ampere. What is the Work done by 1)...

In connecting a battery to a capactor, doubling the spacing halve the capacitance while keeping voltage fixed. Why?