Battery life Definition and 30 Threads

I have a 6 years old MacBook air, still running the OS of a couple of years ago. Lately, battery life is going down (around 4.5 hours of light/medium use) so I mainly use it as a desktop computer, connected to an external monitor. However, when I leave it in sleep mode (still on, but shell...

Hello Everybody! I am new to electrical engineering and only had 1 formal intro class on the subject (albeit I did very well in it) and have found myself in a position where I need to design a circuit for a micro reflex sight I have been designing. So let me first describe how my competitors...

After so many cycles, rechargeable Li-ion batteries powering electric cars go bad. This I know. I am wondering what goes bad? Is it the electrolyte, the electrodes, or both? And in general, could it be possible to take these degraded battery components and fix them? Thanks in Advance! Mike

Dear friends. I am a cardiovascular health researcher writing on behalf of my research team based in Copenhagen, Denmark. We plan to conduct a high-altitude field study on cardiopulmonary function assesed by ultrasound on Aconcagua summit in near 7000 meters altitude. Reports say it will be...

I have four 125 ah batteries powering a 6000 watt inverter. The inverter is supposed to have a no load draw of 2 amps. I have a 12 amp 120volt Ac load. How long should I be able to operate before drawing my batteries to 50%

Batteries and rate of charge? I have an IPad. It 'seems' that when he battery if fully or mostly charged it lasts proportionately longer than when less charged. For instance, all things equal, the battery takes a shorter time to drain from 30% charged to 10% than it does from 90% to 70%...

Hello Guys and Girls, I wanted to know if my HYBRID HONDA CIVIC 2010 would still start up and run if my hybrid battery pack dies ? If it gets started and i am able to drive it, will it affect the car anyhow (apart from few MPG less) on a long term ? Thanks in advance. N.R.

I'm shopping for a battery-powered USB charger. Someone on Amazon says that as current (amperes) increases, battery life decreases exponentially. He says that using a charger with a current of 500mA gets you 30% more total power from the AA batteries than if you used a charger with a current...

Hello Guys My baby is a Suzuki GN125H (Bought in year 2013). I have been pondering for a while to have some kind of dash cam installed on her. Thus I thought to have a power supply installed so as to get power for the dash cam (only to be used when the motorcycle is ON and running). My...

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

For a physics project, we have to increase power to an automated wheelchair. This wheelchair has: Battery Capacity 2x60AH Battery Needed (x2) GR 24 I know that this means there are 2 batteries at 60 Ampere-hours. I don't know what a GR 24 is. Also, I don't know how to increase...

I got a lithium battery pack for my ski glove. On high it last for 2 hour, 4 hours for medium but on low it only last 3 hours. Why does the battery not working long on high? Does the cold weather affect the batteries from operating at its peaks power. Would it be better if I use some type of...

Hi, I want to know what is the proper methods to prolong lithium battery life: When Should I recharge the battery(at any level 90%, 70 or 40 etc)? Should I charging it fully at 100%? is true that discharging battery below 20% once each month is useful to boost battery life?

Sorry for not using the question template, but I don't have any relevant information, like equations or solution attempts at this, since I literally have no idea where to start. Google has failed me. This isn't necessarily a homework problem, but it is for part of a project I am working on...

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 !

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...

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? :]

Hi guys, I'm interested in developing a small gps receiver that I can fit into a certain object so that when it gets stolen I can send a text to it, find the coordinates and track it. The sixe of space for the gps device to sit in would be approx ∅30mm, length is not an issue. I am not an...

Dear Experts There are solar charging devices in the market for electronic devices. These contain some electronics which I suppose is to regulate the power or as controller. Lets say I have a 6 volts device and I have a solar panel rated at 6v. If without any electronic controller...

I have been trying to maximize the life time of my laptop battery. My approach to that is to almost use up the charge in the battery then immediately charge it. It is always annoying when the battery have 5% left, because that's when it hibernates automatically. Can I change the settings so it...

Homework Statement Electric motor in put power rating is 17.5kw Voltage is 48V Battery is 7.5kw/h Average W needed to maintain motor per sec is 1446.7W Homework Equations Motor: W=I*V > I = 364.58Amps The Attempt at a Solution My attempt: If 1kw = 3.6 x10^6J > 7.5 * 3.6 x 10^6 =...

So I know that when an electronic device powered by batteries is turned off, the batteries actually continue to move charge and will lose energy over time. I keep emergency flashlights in storage and I usually put one battery in them backwards so that a circuit is not completed. What I want to...

I have a first generation Apple iTouch 16 GB, and frequently download podcasts to watch and listen to. With over 1 million applications written, I have searched in vain to locate an application that will allow you to launch a video, and instead of displaying video and audio to suppress the...

I am trying to determine how long a particular battery will last for my application. These numbers are just for an example. Battery stats: 12 V 7 Ah Application 1700 W Power=Current*Voltage 1700W = Current * 12V Current=141.7A Time = 7Ah / 141.7A Time = 0.05 hours Is this...

:confused: Hello Could you tell me is there a way of accurately measuring battery life? Basically I have a listening device, it requires 2 x AA batteries, say 2400mAh each (so...4800mAh in total). I am aware you can ‘estimate’ battery life by determining the device’s current consumption...

Hello, I have 2 24V lead acid batteries in parallel to make a power supply for my circuit. I want to do some drain tests, and plot a curve for % energy remaining vs. time. The load on the battery isn't that large, and I don't want to have to supervise my experiment for 12 hours solid. Im...

I bought a fairly cheap wireless mouse a while back. With the batteries it came with it lasted quite some time, at least a few months, before it died. I bought new batteries from the store that were on sale and put one in. About a week later I found that the usb plug had come detached from...

I got a 5mW (class 3A), 650nm laser pointer yesterday and it came with 3 AG-3 button cells and over a day, it was on for about 60 seconds, maybe more however I noticed the beam wasn't as bright as it was when I first put it on. Over 30 seconds worth of use, it seemed to dim further until I...

Using a 150w inverter to power the mac mini & LCD monitor in my truck camper. My Kill A Watt meter shows that the draw (on regular home power) is about 55-60 watts, or .05 KWH per hour. Can I assume that I could use this set-up for several hours, if need be, without danger of depleting my...

My Sony Ericsson T200 cell phone is ~4 years old. (I know, vacuum tubes and dial knobs). It is no longer made. Thus, they no longer make the batteries either. My battery's life has become quite short, lasting only a day or two without use (it used to last all week), so I'd like to replace it...