Battery Definition and 1000 Threads

Homework Statement A battery with constant voltage of 4V and 2 A-h, find the energy (in jouls) stored in the battery when it is fully charged. Homework Equations A-h=3600 C 1 Joule= V*C. The Attempt at a Solution We have 2A-h=7200 C, and Joules are volt-couloumb, so we multiply to get that...

Hello I am having a doubt regarding capacitors .I know that when two neutral plates of an uncharged capacitor of capacitance C are connected to a battery of V volts then charges present on the inner surface of the plates are equal and opposite i.e +Q and -Q,where Q=CV . But what will...

I understand potential as follows: V(r) = Q/(4*pi*e0*r) If current flows from high potential to low potential in a conductor, I am keen to know where is the charge Q located that cause this potential difference across the two ends of the conductor. I would also like to know its polarity...

For my project, the Lithium Ion Polymer Battery - 3.7v 2600mAh powers arduino, transmitter and a few other parts. My whole design works on 3.3v. I'm trying to build a circuit to indicate the status of the battery using LED. When the voltage of the battery is consumed below 3.0v, I want to...

Homework Statement What is the emf of the battery shown? there is an external resistance of 2.50 ohm and 4.0 A...The battery has an internal resistance of 0.50ohm Homework Equations V=Ir V= E +/- IR The Attempt at a Solution Since the current is going away the battery then i...

Maybe somebody can help me with the following question on batteries: I have several batteries which I have to charge from different sources. I have solar panels on the roof of my RV, 2 by 3 meters. On a sunny day, they can charge maybe the equivalent of a 100 ah battery. But if I run...

Homework Statement An automobile battery has an emf of 12.6 V and an internal resistance of 0.080 0 Ω. The headlights together present equivalent resistance 5.00 Ω (assumed constant). What is the potential difference across the headlight bulbs (a) when they are the only load on the battery...

Hi all, I hope you're all well :) I am shortly going to be fitting a battery operated device outdoors. Due to the power consumption, I will get 2.5 days out of each battery (max - if I'm lucky). What I would like to do is be able to connect another battery to it before disconnecting the...

I am interesting to know about the manufactures of these products: crystalline silicon solar cells, thin-film solar modules, display screens like: Liquid Crystal Display (LCD), touch panel and plasma, thin film rechargeable lithium ion batteries, lithium ion batteries for electric car, fuel...

Homework Statement The positive terminals of two batteries with emf's of V_1 and V_2, respectively, are connected together. It is V_2>V_1. The circuit is completed by connecting the negative terminals. If each battery has an internal resistance r, what is the rate with which electrical...

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 ...

Can someone please explain to me how water drops generate electricity? I saw this in a Walter Lewin lecture and became very curious to know :)

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...

Hi friends, Why the battery dischargers are so heavy? Thank you very much

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...

What is the minimum amount of power needed to charge a small lithium ion battery of 3.4 V and 2100 mAh?

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...