Battery Definition and 1000 Threads

Hi All I am among the people who bought the nexus 7 without the data capability and pretty much the first generation of its kind when it first appeared at Google's store. After almost a year and a half I have noticed problems with the battery. It's not much of a problem as it is my annoyance...

Think for example a phone or any devices that shows the amount of battery power is left. It shows it as a graphic where you can deem whether it's full, 3/4 full, 1/2 full, 1/4 etc... or shows the actual percentage. What is that measure really showing you? Voltage? Amp hours left (which is the...

How is voltage between two plates, like in a battery, determined? When you have a 5V battery, is that the potential difference between a point on the positive plate and a point directly across from it on the negative plate? If so, that means they have to be parallel in order for the calculated...

I just got my hands on a solar battery charger with a set of usage specifications that makes me believe it will only be useful some four days a month and will take more or less such time to charge a single set of batteries, despite promises on the contrary in the instructions. Since the case is...

Hi, What will happen if I connect an ideal battery across two ends of a superconductor? Assume all contacts are ideal, lossless. Is the current infinitive?

I have 2 batteries for my mobile, and forget which one is new and old. The standard volt is 3.6 V, and I measure the voltage using any standard electric meter. Battery A has 3.86V Battery B has 3.77V Does anyone have any suggestions on whether it is possible determine the new battery based...

I have a 75w 2meter mobile transceiver (Yaesu FT-2900R – 13.8 volts DC, 15 Amp max draw, min draw is .3 A-.7 A ) that I would like to use in a camp type setup. The power source will be Two 12volt batteries (not dedicated) on a small enclosed utility trailer, which will be 20’-50’ away from the...

Hey! A couple of friends and I are building an electrical miniature cable car, kind of like this: (attached below in case the code doesn't work) We're mechanical engineering majors and love this kinda thing but we just started out and don't really know much yet, so we're just looking for new...

Radioactive material ionises the air around it. Carbon nano tubes have an extremely large surface area, & could possibly "store" the ionised charge. If a volume of carbon nano tubes is wrapped around a core of insulated radioactive material, can a potential difference exist between the...

The question and my solution are in the paint document. Can someone tell me if I am correct or not? If my answer is wrong am I on the right track?

Hi. So we all know that electricity requires a complete circuit in order for electrons to flow in a wire. It's my understanding that this is due to the charge differential at the positive and negative, creating an electric potential. So, given that (or correct me if my understanding is wrong)...

Ok, this may be a very stupid question but I just can't find a right explanation. I was reading about how a battery works (i.e. car or AA battery etc) and I found several videos giving the following explanation. (e-) are concentrated on one pole and a positively charged material is in the...

Hello all. I have been working on a side project, a Persistence of vision display. I have had and still have a bunch of problems I must deal with. I feel as though it has something to do with the power needed by the components and the battery I am using. Can someone help with this matter...

i understand that the difference in potential energy creates an electromotive force that moves electron between the anode and the cathode, but what creates that potential difference at the -ve * real not conventional * anode of the circuit ? does the battery take the electron from the positive...

I have a 3x3x3 foot box that I want to light up in a place that does not have access to electricity. The box will ideally be as well lit as a regular room in the evening with red, green or blue light. We anticipate using the box 4 hours a day for 7 days. Given these parameters I am trying to...

Homework Statement a) Calculate the value of the 12V battery b) Calculate the power dissipated in R_1,R_2 and R. https://www.physicsforums.com/attachment.php?attachmentid=60819&stc=1&d=1376202905 Homework Equations I_1+I_2+I_R=0 The Attempt at a Solution For the left-hand...

In reactions that reduce organic compounds through donation of electrons, can a battery substitute as an electron donor? In a typical mercury/aluminum amalgam reaction, aluminum donates the electron to the compound that is going to be reduced. The mercury serves as a mediator for the...

Hi, I'm working on a project to build a solar powered AA battery charger. This is definitely not my profession, I only have a small understanding of electrical engineering. Mostly from what I learned in high school electrical class. Here is what I'm looking to do: I want to charge 16 AA...

Homework Statement Calculate the power Pa and Pb supplied by batteries A and B respectively (see attached diagram) Homework Equations P=iV, P=i^2R, and P=V^2/R The Attempt at a Solution I already found i1, i2 and i3 to be 5.714, 1.143, and -4.571 respectively. I am...

I have a very small project which requires a typical 9v battery for mobile use. But to keep from having to replace the battery I would like to put in a rechargable 9v battery and use a 9v output from a dc power plug to charge it. I have charged batteries with solar panels before and all that is...

Why can't primary lithium batteries (that are not lithium IONS) be developed as secondary batteries? Can someone explain this to me?

Assuming an a suitably accurate weighing device , Would the weight of a completely discharged battery be different from a completely charged battery.

i first formally learned about the cell in my chemistry class. their explanations for how it works was very unsatisfactory for me; so i wondered if this was rather a physics question. i have two half cells connected by a conductor (between the plates) and a salt bridge. i ask people why is...

In 1. (see attached), a is attached to ground, so has a voltage of 0 V. The voltage at b is -1 V, so the voltage across the capacitor (Vb-Va) is -1 V. My understanding is so rusty... What happens when a is now wired to the positive end of a 1.5 V battery, and the negative end of the battery...

This is sort of an engineering question and sort of not but it involves me possible replacing the lithium-ion battery in my iPod Touch. My iPod will not turn on no matter what I do. My iPod says that there is no battery life left in the battery, yet when I took it apart and removed the battery...

Can anyone help me by discussing the charging and discharging methods of ordinary acid batteries which are used in inverters, cars etc and that of the dry cells in detail? Please give me any link where these methods are elaborately discussed.

Hi all! I would like to know how to charge a lithium polymber battery of 3.7V, 110mA battery. Anyone has the circuit ? Help! Thank you!

Hello, I have this circuit: And I'm using this battery: http://www.tme.eu/en/details/bat-6f22_gp/batteries/gp/gp-1604g/# How long will the battery keep supplying the circuit? Thanks !

What is the difference between a capacitor and a battery? As far as I have browsed, the most common answer found is capacitor discharges faster than a battery. Would anybody elaborate it in a clear way.

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...

battery run time for different terrains... i want to manufacture a trike which is human powered as well as motor operated ... for this i am using a 400 watts pmdc motor of 1500 rpm ..two batteries of 12 v and 26 Ah each, the total weight of my vehicle would be 350 kg.is it feasible ?how to...

Hey guys, I am new to the forum and came to here to ask for help on a project that I am trying to construct. I have 3 lithium polymer batteries, one 7.4v, 11.1v, and 14.8v. The current draw will be around 150a for an extremely short period of time (a couple milliseconds) and then will settle to...

A friend of mine lost his battery charger for his airsoft gun and he naturally comes to me for electrical help. Problem is, I'm freshmen level right now. I looked up how to hack and build a basic battery charger, my question is do the internal resistance/impedance of the batteries matter when...

Hi; I want to select a battery 12V-70AH for a UPS (Un-interruptible Power Supply) but problem is “temperature”. The environment temperature where UPS would be installed can be raised up to 42C. So the flooded lead acid batteries can not work there as each 8C of temperature rise decreases the...

i know its not possible but isn't there any way in which two batteries of different capacities or voltages be connected in parallel ? Is there any way to limit the current in that case by using small value resistance to drop the current? or by adding a convertor from high to low current...

Hi; As we know that flooded lead acid battery needs to be top-up (watering) after passage of some time and it is recommended to use distilled water. Many people say that water condensed by Air Conditioner is also very good to top-up the battery. Is it true?

18v drill battery to 5v regulator?? Hi I have been doing a bit of research but am still a little unsure, I am trying to charge an iPhone from a dewalt drill battery, What I have so far is that the iPhone is a 5v 1000ma supply And the dewalt battery is 18v lithium ion Can I use a 7805...

I have taken bits of information from various places to try and come up with my own description of how a battery works but am unsure as to whether it is correct. A battery creates an electric field by separating charges (positive and negative terminals). The electric field then causes positive...

Recently I de-soldered an f-connector (coax) from a pre-made circuit board. This consisted of 3 soldering connections, 1 for the center wire and 2 for the braid which was electrically connected through a mounting plate. Then I attached the V+ from a 18V battery to the where the center wire...

How to fix my laptop battery Lithium Ion when it doesn't charge.My friend says that his battery became stronger when he put it on the refrigerator,so i did also because my battery is having a problems with its charging.When it became full,and I'm using it before 20% it shutdown itself.But,after...

Homework Statement A capacitor is charged by connecting it to a suitable battery. (a) Does the amount of energy stored in the capacitor increase, decrease, or remain the same if a dielectric is inserted while the capacitor is connected to the battery? Explain your answer. (b) Does the amount...

I have been hearing about the possibility of a graphene super capacitor for quite some time now, but it still seems they are not readily available. Is there anyway for me to get my hands on one? Would it be possible for me to buy/make one practical enough to replace a AA battery? What size...

Hey okay, so I have a 12V source which can provide a max of 10 mA, and I also have a switch that can go from open to close in 1 ms, How can I create an inductive circuit that will create a spark gap between electrodes that are 3mm apart? I did the math and found the breakdown voltage to be...

So I'm wondering about Motor being used in Tesla Auto/Car and battery which powers it. From their website the specs are like this: 1] 302 hp (225 kW) 5,000-8,000 rpm for 60 kWh battery gives 317 lb-ft (430 Nm) @ 0-5,000 rpm 2] 362 hp (270 kW) 6,000-9,500 rpm for 85 kWh battery gives 325...

Hello All, I was wondering if anyone could check this since I am not very good at physics (understatement). Thanks a lot! :smile: "A 1.5 V battery is rated at 1,800 milliamp hours (mAh). This means it can suppy a current of 1.8 A for 1.0 hours before running out of charge. How much...

I understand how a galvanic element works at an electrochemical level. I understand how the electrons move from the anode to the canode, and also how electrolysis works. I do not understand how to relate the following in an electrochemical perspective: Battery that drives charge through...

I want to build a usb charger that works with solar power (and later add a crank dynamo too). The photovoltaic cell will charge rechargeable batteries and they will charge the usb device, like my smartphone. The smartphone charges with 5V and 1500mAh. I'm planning to use 2 AA batteries 3.4V...

Hi all! Excuse the simple nature of this question, but I'm a mechanical engineer working on building his own PAS bicycle and need to understand this to go ahead with my work. I understand that a 12V 7.2 Ah battery ideally discharges 7.2 ampere of current at a nominal voltage of 12V for 1...

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...

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...