What is Car battery: Definition and 66 Discussions

An automotive battery or car battery is a rechargeable battery that is used to start a motor vehicle. Its main purpose is to provide an electric current to the electric-powered starting motor, which in turn starts the chemically-powered internal combustion engine that actually propels the vehicle. Once the engine is running, power for the car's electrical systems is still supplied by the battery, with the alternator charging the battery as demands increase or decrease.

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  1. R

    What could be draining the car battery and how can it be fixed?

    Our car battery is past its warranted life by 1.5 years (it's 5 years old). It's been discharged a few times due to lights being left on overnight. We're not currently using the car because of engine issues, so it just sits in the driveway for the last few months. Last week, it was found...
  2. DagmaarUlereich

    Outlet adapter to mimic a car battery to power 12V devices

    Sorry if this is a very simple question but i have been googling and looking around for a straight anwser but can seem to find a solid answere or draw a solid conclusion from information I've reached. So I have a rgb led light for a car, the box says input 12vDC. if I wanted to set these up...
  3. dlgoff

    New Car Battery Plant Construction in the Midwest

    Panasonic is going to build an electric car battery factory plant in DeSoto, KS. Will hire 4000 jobs at the plant and another 4000 jobs throughout the state. IIRC, the factory will cost 4 billion dollars to build. edit: corrected spelling of DeSoto
  4. S

    Why would disconnecting the positive cable first on car battery cause sparks?

    When I was 18 years old, I worked at an automobile repair shop doing oil changes and other light mechanical work. The automobile repair shop hired me for this work to free up their real auto mechanics to do more advanced automobile repair work. One time I was assigned the task of replacing a...
  5. russ_watters

    Auto/Motor Car Battery Charge Level Issue

    I drive a 2019 Kia Stinger (purchased in June, 2019) with 22,000 miles on it. It's been having weak battery issues for a while, and I've ignored it but I really shouldn't, so now I'm trying to diagnose it to see if I need a new battery, new alternator or if there is a deeper electrical system...
  6. L

    Automotive Jumpstarting a dead car battery

    When using two cars to jumpstart a dead battery. Why can't you connect the negative jumper cable to the negative terminal of the dead battery (which is what I commonly do) but instead need to connect the negative jumper cable to grounded metal...
  7. H

    Boosting a petrol generator with a car battery?

    Hi All, So i am looking to buy a petrol generator to run a 2.2KW electric motor. I was thinking of getting a 3KW model which under normal conditions this should be ok - but on start up I've been told an electrical motor draws 6 to 10 times the normal load, which is way too high for the...
  8. Wrichik Basu

    Automotive Death of a car battery and related issues

    We have a Toyota Etios Liva, four years old, petrol variant. Today, my father took it for annual servicing at the authorised service centre, where the service personnel declared that the battery was "dead". Our car is not used much. Usually on an average, it is driven for around 14km per month...
  9. M

    Car reading 17V+ in the battery when running, how to fix?

    Hi, I have a 2004 Toyota Matrix with 270 000km. It's working great but today when i started my car the battery was going up to 17.2V (i have a battery voltage reader in the car at all time). It's the first time it went up there, it usually stays in the 13-14V. I know something is wrong and I...
  10. Reinis

    Electrical Powering an LED strip from a car battery?

    Hi everyone! I am a new one to the world of the LED lights. However, I have an oncoming project with LED strips. There will be 3 separate runs of a LED strip (4 meters, 4 meters and 6 meters each). In each run LED strip will be put in 1 meter long LED strip profile. I am planning to connect the...
  11. R

    Internal Resistance of a Car Battery

    Homework Statement An automobile battery has a terminal voltage of 12.8 V with no load. When the starting motor (which draws 90A) is running, the terminal voltage drops to 11.0 V. What is the internal resistance of the battery? Homework Equations V= EMF- Ir The Attempt at a Solution I think...
  12. duhuhu

    Can you damage your starter motor with too much current?

    Hey all! Today I took my car to the shop for some starter issues. They told me that the starter had been damaged by a battery with a higher CCA rating than was safe for the starter motor and it burned out my motor slowly over time. I feel like they may be BS'ing me, but I'm not sure. I know my...
  13. J

    Automotive How long is too long for a dead car battery

    I have or had two good car batteries one was a deep cycle they were connected to a 20 Ma led it could have been as long as four months since solar charger stopped working on top of that they were outside in temperatures as low as minus 25 degrees fahrenheit, what I want to know if one took a new...
  14. J

    How to generate 100 watts of heat from a car battery

    I have lots of batteries 12 volt charged by the sun what I need is something that would draw 100 watts and give heat when connected to a car battery? I have ac heating pads, 2000 watt hot water elements lots of copper wire, light bulbs any other ideas?
  15. Grands

    Automotive Which is the best brand for a car battery

    Hi guys. I need a battery car, do you know which is then best brand? I've heard about dyno, does someone who about it? Thanks.
  16. K

    Is charging off of a car battery harmful for the car?

    Hello everyone, I'm a RC helicopter enthusiast and want to fly in the field where there is no AC wall socket available for charging the helicopter's battery. The helicopter's battery is a 7.4V 1500mAh Lipo (11.1 Wh). My car's battery is 12.65V 74Ah. There is a charger available for charging...
  17. J

    How can we recover all the lead from old car batteries?

    Years ago I thought I would take apart a car battery melt all the lead I thought there would be at least 10 or more pounds of lead I only got a little over a pound of lead there was a lot of heavy dirt but applying heat to this material yielded no lead it seems the acid eats or corrodes the lead...
  18. H

    Automotive Understanding 12V Car Battery Voltage Readings: Explained

    Why are these batteries stated as 12V batteries if often they have a reading of greater than 12V e.g 13 or 14 and when you rev the engine hard while in neutral and do a voltage test on some components in the car circuit you get a reading of much much greater like 40V! How is this working? Could...
  19. J

    How much AC is there in a car battery

    I am thinking there is about 1/2 kilowatt hour of usable electricity in an 800 cca 12 volt car battery after conversion is this right?
  20. Akmalidin

    Car battery -- charging questions

    Hello, I am a Telecommunications student who does not have a lot clue about cars.Does a car charges up its battery when it moves? What power supply is used for lighting in car, the battery? So if car charges the battery when it moves, why sometimes external/additional charging of battery is vital ?
  21. PenguinCo

    Boiling water w/ a car battery

    So... I am looking to basically convert electric energy to thermal, then mechanical energy. I am wondering how practical it would be to use a rechargeable car battery (12V, and 40Ah) to boil water into steam for a steam engine. It does not matter how long it would take, simply if it is...
  22. Gamma

    Car Battery Safety in Lab: Risk Assessment

    Hello everyone, How much of a safety hazard is it to store a car battery inside a classroom/lab? It's a new battery and it is plugged into a charger all the time. I use is only couple of times per year for a demonstration. Thanks! -Gamma
  23. Kurtis McIntosh

    Engineering Circuits Question -- Charging a car battery in 4 hours....

    Homework Statement A constant current of 3A for 4 hours is required to charge an automotive battery. If the terminal voltage is 10 + 1/2 t V, where t is in hours, (a) how much charge is transported as a result of the charging? (b) how much energy is expended? (c) how much does the charging...
  24. M

    The final answer to the car battery on a concrete floor (ruins the floor)

    People keep asking about setting a car battery on a concrete floor somehow ruining the battery. Here is the final answer on the subject. I have the 1930s Popular Science with the original tip in it (but don't ask me which issue). The auto tip was: "Leaving a car battery on a concrete floor...
  25. G

    Wanting to run the following motor using a 12V (car battery)

    I am hoping to run the following motor using a 12v (car battery). This battery would run until a charge is needed Just curious on what's needed for an Inverter and how easily/cheap it could be accomplished.. Motor specsFHP-Motors 1~mot. 100w 115v 50/60 MHz I'm novice in...
  26. J

    Emulating car battery output through home power?

    I'm setting up an amplifier which is intended for use in a car, and I'm not using it in one. I'm trying to power it through a typical DC 250 volt wall outlet. What kind of transformer should I use? (I'm also trying to power a car stereo with it as well)
  27. Shanevan

    Can you charge a 12v car battery with capacitor?

    can you charge a 12v car battery with capacitor
  28. T

    How long will a 300 CCA, 12V car battery last with 18Ah?

    If CCA can be translated directly to Amps then would I be able to run the battery at max capacity for only 3.6 minutes? 18 / 300 * 60 = 3.6 Minutes? Or am I looking at something wrong?
  29. russ_watters

    Automotive How long to charge Dead Car Battery

    Just got a jump start due to having left my trunk ajar last night. Battery was pretty dead ~8.5V. Dead enough that we had to let the jumper car charge it for 10 minutes before it would start. So now it is running in my driveway. How long do you think it will need to charge before it will be...
  30. J

    10 Watt Solar To Car Battery With Diode

    I have an 800 amp car battery no load connected at anytime to a 10 watt solar panel with just a regular diode in between after 4 or 5 hours in the sun terminal voltage reads 16 volts is this good? Would a battery connected this way last longer than one that sits idle uncharged for 6 months? John
  31. E

    Car battery/ aux battery wiring question

    I have a diesel van that has a dual battery starting system. Each battery has 850CCA. I have 75w of roof mounted solar panels that are running through a 100amp controller and charging an aux battery that has 55amp hours. All batteries are 12v. I would like to be able to charge my aux...
  32. S

    Will a car battery be able to run this?

    Im trying to calculate if a standard car battery will be able to run 2 computers, 2 monitors, and some small hardware, and if so, for how long. The entire configuration should be no more than 1000watts. (400 each computer, 50 each monitor, and 100 for small hardware). I can't seem to find how...
  33. C

    Could a Tesla turbine recharge electric car battery?

    Assuming you have an electric car that can go 100miles at 70mph on a single charge, what kind of range could you get with the following configuration? An electric car that runs off the main battery bank. Vents on the outside of the car funnel air to a Tesla turbine while the car is in motion...
  34. 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...
  35. 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...
  36. 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...
  37. 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? :]
  38. C

    Homebuilt electric car Battery conundrum.

    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...
  39. cepheid

    Dead Car Battery Load when car off

    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...
  40. K

    Does a car battery charge and deplete at the same time while running?

    Homework Statement Obviously I do not believe this to be the case, but when running a car the battery is I assume having current drawn in, reversing its normal means of depletion so that the potential chemical reaction can take place later on. My question is when you turn on the radio while...
  41. O

    Electro-Magnet with a Car Battery Help

    Hello everyone. I'm glad to be part of the Physics Community, I've read a lot of interesting threads, and I think now I'm ready to be party of it! For my project, I'm trying to create a ElectroMagnet using a Car Battery. The specifications for this battery are.. 12V 390A 65 RC -...
  42. 9

    12V Car Battery Amps: How Much Current Generated?

    hey guys can anyone pls say how much current in amps does a ordinary car battery of 12v generates?? pls...
  43. C

    What is the maximum power and corresponding current for a car battery?

    Homework Statement The voItage U of a car battery decreaces as a function of the current I according to the formula U(I) = 12-0.3*I The power P of the starting motor is the product of the current I and voItage U , P(I) = U(I)* I. Homework Equations Find the maximum value of the power and...
  44. P

    Solving Car Battery Power Output Problem

    Homework Statement A car battery with 12V EMF charged to 120amp hours. Assume potential difference across terminals is constant. How long can the battery deliver energy at a rate of 100Watts. Missing is current (i), internat resistance (r), and real voltage (Vr)Homework Equations (Amp...
  45. K

    Car Battery Circuit: Current Through Starter & Dead Battery

    Homework Statement Two parts: With the jumper cables attached, how much current passes through the starter motor? With the jumper cables attached, how much current passes through the dead battery? Homework Equations Ohm's Law and Kirchhoff's Laws The Attempt at a Solution...
  46. V

    Car Battery Problem: Can Reversing Polarity Harm My Car?

    Car Battery Problem! Hi all, I have to tell my story before actully asking the question. So, please be a bit patient! I went overseas for a holiday for 3 weeks. Before I went, I washed my car. Unfortunately, I forgot to turn off my cabin light. Of course, I couldn't start up my car when I...
  47. T

    The current given from a Car Battery?

    Hi guys, this is my first thread, and I am not sure where I'm supposed to put this so I hope this is ok? if not, please tell me how and where i can move it to Ok, just a simple question that i can't seem to find anywhere, what is the current which is given out by a car battery? Thanks, Tinger
  48. S

    How long does it take to charge a 230CCA car battery?

    I have a 230 CAA car battery, and 2 solar panels in a parallel circuit (one is 15V, 300mA, 4.5W, the other is 15V, 125mA, 1.8W). I know that these are under optimal conditions, so please assume that they are. How long would it take to charge my car battery with these solar panels?
  49. M

    How Can I Build My Own Inverter to Convert Car Battery Voltage to 220V AC?

    Hey all .. i happy to join this forum because of the amount of information that it has .. In our city , the electricity cut down for long time may be 10 hours in a day .. I want to make a device so i can convert the car battery voltage ( 12V DC) to (220V AC) this device called Inverter .. i...
  50. E

    Car Battery Rapidly Losing Voltage Difference

    I'm attempting to figure out why my car isn't starting. I've reseated all the grounds and made sure the ground connections were clean and bare. I've cleaned the battery terminals and clamps with a wire brush as there was some corrosion on the terminals. I charged the battery two days ago due...