Battery Definition and 1000 Threads

  1. W

    Cheaper Electric Vehicle Battery?

    I notice that electric vehicle batteries (such as the one in the Tesla) are made of a bahzillion little batteries. I also notice that electric vehicle batteries seem to be absurdly expensive. A small battery is made of a case, some metals and chemicals. Can they not scale up this process...
  2. B

    Understanding Battery Discharge & Peukert's Law

    Homework Statement i have to do a scientific research about finding the best batteries specifications. for this case the battery should last long as possible . there are 3 characteristics : Voltage , Capacity and inner resistance . i have measured voltage over the time. when i used smaller...
  3. A

    Calculating Energy Stored in a Fully Charged Battery

    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...
  4. V

    Capacitor having equal charges on plates connected to a battery

    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...
  5. wirefree

    I don't understand Electric Potential in battery

    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...
  6. S

    LED voltage indicator for 3.7v lithium ion battery

    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...
  7. J

    Calculate the emf of Battery w/ External & Internal Resistance

    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...
  8. D

    Can Different Same-Voltage Batteries Be Used in Parallel for Discharge Only?

    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...
  9. M

    Electromotive force of automobile battery

    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...
  10. D

    Battery backup to a battery supply.

    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...
  11. I

    Manufacture of solar panel, display, lithium ion battery and PCB

    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...
  12. H

    Two battery hooked up in series, energy conversion

    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...
  13. JJBladester

    Single battery & Single resistor: Series or parallel?

    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...
  14. J

    Getting correct wattage from lead-acid battery

    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...
  15. S

    Potential Difference ( Battery + Motor )

    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 ...
  16. V

    How Water Drops Generate Electricity: Explained

    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 :)
  17. P

    Capacitors are charged, disconnected from battery, and had plates swit

    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...
  18. M

    Why Don't My Car's Electronics Work During Parasitic Battery Testing?

    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...
  19. E

    Is there a way to determine if a booster pack (battery) is still good?

    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...
  20. M

    Automotive Are Battery Issues Hindering the Development of Automotive Power?

    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
  21. M

    Is a 12V car battery more powerful than a 12V power adapter?

    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...
  22. H

    Is Back EMF Always Equal to Battery EMF in Inductive Circuits?

    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...
  23. perplexabot

    Charging a car battery question.

    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...
  24. J

    Why the battery dischargers are so heavy?

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

    Stopping discharging a battery during charging

    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...
  26. B

    Real Life Car Battery Experiment

    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...
  27. C

    Motor Power, Torque & Battery Run Time for Miter Saw Tool

    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...
  28. F

    Can a voltmeter help troubleshoot a ceiling fan remote control battery issue?

    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...
  29. Greg Bernhardt

    Problems with the Dreamliner battery

    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
  30. Astronuc

    The Ultimate Battery: Overcoming Infernal Challenges

    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...
  31. C

    Potato battery, how does it work?

    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...
  32. S

    Engineering How to make a Logic Circuit with 5 LEDs and a 3V battery? Nothing else allow

    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...
  33. J

    Battery charging circuit - can anyone explain?

    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...
  34. 2

    Electromagnetic motor using battery and magnet?

    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?
  35. B

    Perpetual Battery with Pickup Coil and Magnents

    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...
  36. Q

    Battery Life Cycle: Explaining DoD vs Life Cycles

    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...
  37. D

    Minimum amount of power need to charge a li-ion battery

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

    By how many volts is the battery 'loaded down'?

    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...
  39. T

    Can You Charge Batteries with a Magnet and Copper Coil?

    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...
  40. B

    Monitoring Battery Level, without wasting too much energy

    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...
  41. E

    Battery Charge Controller using a VRDC

    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...
  42. trollcast

    Battery charging circuit problem

    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...
  43. W

    Are overdischarged batteries a fire risk?

    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...
  44. M

    How to calculate power provided by a battery

    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 =...
  45. J

    Why is capacity not stated on primary batteries?

    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...
  46. J

    Where exactly is the battery in this diagram

    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...
  47. P

    How Fast Should an Electric Car Travel to Maximize Distance?

    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) =...
  48. Z

    Why Doesn't My Potential Difference Calculation Match the Given Answer?

    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...
  49. F

    Building a Battery for a Shoebox-Sized Vehicle

    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
  50. Square1

    Automotive Car battery life - playing radio

    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? :]
Back
Top