An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy

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10 views

Safe discharge cut off point for 12v SLI calcium lead acid battery

I want to make a circuit that cuts off a mains power inverter connected to a vehicle's battery. I have found, however, SLI batteries come with very sparse specifications. For example, the Varta E43 ...
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1answer
39 views

Why do laptop batteries and chargers differ in voltage output?

As an example, my laptop's charger gives out 19,5V and 3.42Ah while it's battery gives out 11,1V and 2.2Ah, what's going on exactly?
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1answer
43 views

charging circuit for series coin batteries

I am designing a circuit that will be powered by two rechargable coin cells in series, and I need to include a module to recharge them in-situ. I have had a look on RS at the range of rechargable ...
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2answers
38 views

0.5m of RGB LED strip light with micro RGB controller powered by 12v li-ion battery pack?

my questions are all pretty basic but I'm very new to electronics and could really use the help. Ill try and be as specific as possible and would appreciate any advice. Abit about me - Im UK based ...
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2answers
65 views

What exactly are surface charges and what do they do?

How does the voltage/electric field of the battery relate to the surface charges on the wire? What determines the amount of surface charge on the wire? (Why more near the battery, less farther ...
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2answers
345 views

A few questions about basic capacitor concepts

So say you a typical setup like in this diagram. How does current flow while the capacitors charge? To elaborate, what is the mechanic that makes capacitors mimic the functionality of a wire ...
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1answer
39 views

Maintaining DC voltage with more batteries

I have a circuit which i am powering with two 1.5V AA batteries that dies at 2.6V volt as the battery discharges. Reading around, i realized that even though there is energy in the batteries, my ...
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1answer
125 views

Direct power from different terminals in a series of batteries

I didn't find any answer to this simple question, but please correct me if so, and feel free to edit this to be readable or more general (I'm not good at these technical terms in English). I want to ...
2
votes
1answer
50 views

How many LiFePO4 cells can be in parallel?

How many lithium iron phosphate (LiFePO4) can safely be connected in parallel, in order to achieve higher power output (and capacity)? Wired directly together, without components such as resistors or ...
2
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3answers
69 views

How to gauge safety of cheap Lipo batteries?

I see a ton of cheap 12V lipo batteries for sale on Ebay, but other than the mAh rating, I can't find any info or datasheets on how to safely operate them. I'm looking for a good battery to power a ...
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0answers
14 views

Shifting of battery in BMS

I was working over the topic Battery management system where now I have encountered a problem due to lack of proper knowledge in this field. My Problem statement is to achieve an uninterrupted power ...
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3answers
75 views

Power Circuit for Raspberry pi portable

I am building a hand held portable raspberry pi. I have just plugging the battery in and using the thing, but I want to make the battery completely part of the unit without the need to unplug it when ...
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0answers
39 views

Switch based on battery voltages

I have two batteries. I would like a circuit which looks at their voltage, and puts them in parallel if they are the same. If they are not the same, the one with the higher voltage should be taken out ...
0
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1answer
18 views

Calculating the right battery capacity

Apologies for what is a probably an easy question but I can't wrap my head around calculating the battery size that I need. I have a circuit with total power of 2.754W and current of 1.32A. I am ...
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3answers
975 views

Can a diode effectively regulate a supply voltage?

I have a 6V DC battery that's rated at 2A. My microcontroller uses 5V supply at about 50 mA. I've been told I shouldn't worry about the current since the microcontroller will just take what it needs. ...
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0answers
22 views

Supercapacitor sizing from its energy curve

This is related to my final year project at uni and it about hybrid energy storage and the limiting of losses between two devices. So I've been told that you can find the size of a supercap by ...
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2answers
54 views

1800mAh battery charge with 450mAh

Can I charge my 1800mAh battery with 450mAh? My 1800mAh battery is for my smartphone, and Im using a 9V niMH battery 450mAh to charge it. Basically, I used a regulator to make the 9v input to 5v ...
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2answers
55 views

I have an Arduino with multiple sensors and want to know the total current/power consumption of the system

I have 3 PIR sensors, a piezo buzzer, 3 simple LED's, the Arduino system, and 2 temp. sensors. I plan on using a 9 volt battery and implementing sleep mode during the running of the system. What ...
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2answers
63 views

How to efficiently boost a low voltage high current input to a high voltage low current output

I have a 3.7V 6600 mAh lithium-ion battery that I'd like to use to power some small 6V motors that only require 500 mA. However, I need the battery supply to last as long as possible (which is why I'm ...
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1answer
56 views

Energy stored in a battery, formula?

Consider schematic below. simulate this circuit – Schematic created using CircuitLab With a DC source we can use this arrangement to find the force between the plates of the capacitor. ...
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1answer
92 views

Shut off circuit when under a certain voltage?

I have three batteries wired in series, in order to produce 9v. If one of those batteries dies, I need the whole circuit to shut off. The best solution I've found is to use a comparator, but the ...
0
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1answer
52 views

How can I parallel a battery supply and AC supply?

How can I proceed if my battery does not supply all the charge I need and want to compensate by supplying the rest with an AC source connected in parallel with the battery?
1
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1answer
37 views

What is a reasonable sustained current load for a typical AA Li-Po battery?

I would like to build a cutdown mechanism for a balloon's nylon rope using NiChrome wire. To make the cut-down mechanism as simple and cheap as possible, I want to stick to using AA batteries. To ...
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1answer
46 views

If I have three button cells in series, and one of them dies, will the whole circuit still function at a lower voltage or will it stop flowing?

If I wire three button cell batteries in series, their voltages should be summed. Now, if a battery dies, let's say BAT3 for the sake of example, will the circuit ...
56
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12answers
6k views

I am a quadriplegic. Would it be possible to power my ventilator humidifier with a battery?

I am an absolute novice in regards to electrical engineering, and so I am hopeful your expertise can guide me in the right direction. I know this is an unusual post for this forum, and so I thank you ...
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1answer
40 views

How to calculate lithium-ion battery energy density

According to this battery comparison sheet, lithium-ion batteries should have an energy density around 110-160 Wh/kg. Wikipedia cites it may be around 100–265 Wh/kg, although it refers to it as ...
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0answers
24 views

What on / off switch to use from a 2S Lipo to a Switching Regulator

Last time i used the Slide Switch for my application, everything worked well. The system has 2S (7.4v Lipo) Battery - Fuse - On/Off Switch - Switching Regulator - load ( Beaglebone + Wifi Module). ...
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1answer
47 views

TA/USB battery charging

Apologize if the question seems silly, searched for the answers on google but couldn't get an answer, so please manage to help. I am studying detailed charging process of a smartphone ...
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2answers
146 views

How would I convert a 4.1(ish) volt li ion battery to 240v ac?

I'm fairly interested in electronics but not very educated in it. I was wondering how I would go about safely converting your average li ion battery pack to a usuable voltage (240v ac) for things ...
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votes
2answers
582 views

LED burnt out with 2x AA (or AAA) in series

Why does a LED burn out with 2x AA (or AAA) in parallel series, without resistor, but not with a single CR2032? Both are practically the same voltage, right? The led is a yellow from the Arduino ...
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2answers
39 views

stabilized symmetric power supply from battery

I'm making ECG device and for that I need a dual power supply. I decided to use 3 x 9V batteries and below there is my scheme: unfortunately I encountered a problem. I created that power supply ...
0
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2answers
73 views

How to calculate battery capacity from its size?

If the battery is for example 3.5mm x 14mm x 20mm and is 3.7V what is it's capacity? How accurate can such calculation be?
2
votes
1answer
373 views

9 Volts battery is draining fast in Arduino

I am currently working on a project using Arduino UNO and two 3 volts DC motors. I chose a 9 V Goldtop battery to power my two motors. The two motors seemed to work fine until after some time, a very ...
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2answers
65 views

What is a dead battery cell, what causes this to happen, and what are the implications?

Today I had a bit of car trouble where the culprit turned out to be the battery. I had driven my car just 5 minutes earlier without issue, but upon attempting to crank the vehicle it made a final ...
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votes
3answers
120 views

Whats the effect on Voltage and Amps when 244 9v batteries are connected in a series?

There are many opinions about a stunt a guy did on youtube, where he connected 244 9v batteries together in series. Can someone clarify the magnitude of Current being limited by the chemical ...
0
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1answer
33 views

having different voltages from 2 batteries in serie (3 voltages…)

for a project, running on battery, I need 3 different voltages (+/-3V and 6V) +/-3V for OpAmp and µC (attiny85 will be plug to the 3v) 6V for the actuator I was thinking about using 2x CR123 (3V ...
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0answers
53 views

How to charge lithium-titanate battery with lower voltage

I would like to charge a lithium-titanate battery rated at 2.4V (capacity 50mah, max charge voltage 2.75V), which is lower than the typical li-ion battery (3.7/4.2V). Most charger ics seem to be ...
-1
votes
1answer
54 views

Switching between different batteries!

I Have got a project wherein I have to achieve this! Please neglect the charger set up for my block diagram. Since I am a newbie to electronics, I am unable to get any idea how I would switch ...
1
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0answers
40 views

Prevent desktop from switching off when power inverter switches from mains to backup

I'm using a desktop computer over a power inverter that's connected to a 12V lead acid battery. When the main power supply fails, the inverter switches to battery backup and can power my desktop for ...
1
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1answer
37 views

Can i charge 2 li-ion 12v bateries in Series?

i am making an external batteries arrangement for my laptop. in this i am using two li-ion 12V batteries. now i am facing problem to charge this batteries in series or in parallel? i have tried to ...
2
votes
1answer
58 views

Computer Power Supply to bench top theory

I want to use my Corsair 430CX as a benchtop power supply to do small circuit work. I am fuzzy on the theory however when it comes to the amount of amperage that the rail can support. It worries me, ...
4
votes
5answers
601 views

Using DC current to operate a fish feeder that takes 2 AA batteries [duplicate]

I'm a complete electronics newbie. I have a auto fish feeder that takes 2 AA (1.5V) batteries. After changing the batteries quite often I got curious to find out if the feeder can be modified to run ...
-3
votes
1answer
40 views

what is minimum amount of current to charge a battery, suppose if we connect 150 AH Battery to UPS? [closed]

This is anji, If we use a battery with ratting 12v C10 in UPS then what is the current value to charge the battery?
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1answer
115 views

What's the name for this connector?

Recently bought 3.7mAH li-ion batteries on ebay (it's labelled for use with RC toys, but I'm using it for DIY projects). Will need to buy the female adapter. Here are some pics: EDIT: Well then, ...
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0answers
38 views

Can a joule thief circuit be made to both boost or buck an input voltage?

In the normal run of things I would use a 555 or something similar to generate a PWM signal as the base for my power supply. The caveat is that for my application I need continuous operation from an ...
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votes
0answers
22 views

auto shut down of a 9v carbon-zinc battery [duplicate]

i feel voltage drop of a 9v battery for a continuous use nearly 30 minute for 35ma load.but,after 5 minute resting ,battery regains its voltage and performs well . so,i would like to choose auto shut ...
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0answers
28 views

9v carbon -zinc battery voltage drop and regain its original state [duplicate]

i am using 9v carbon -zinc battery with 35ma load,including regulator and other circuitry. its working well for first 20 minutes,after battery voltage drop less than 6v and entire system will shut ...
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2answers
156 views

Portable Batteries for the Raspberry Pi

I am building a project involving a Raspberry Pi. It is known that the RPi runs around an average of 700mA of current and my project would probably need a little over 1A of current due to attached ...
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2answers
152 views

9v battery voltage drop and regain its voltage

as a part of my project , i have to develop +5v from an 9v carbon-zinc battery with 7805 regulator.it is given to microcontroller and some other circuitries .it consumes nearly 40ma. but,the problem ...
0
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1answer
65 views

Ratio Between Voltage and Charge

Is there a ratio between the voltage and charge of a battery? I mean, the voltage falls slowly while the charge is consumed? Or occurs a sudden drop of voltage when the charge is at the end?