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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11 views

Show charge state of a car battery

I'm building a mobility music box, powered by a car battery (12v, 74Ah). What can I build into this box to show the current charge state (read somehow from a display if the battery should be changed)? ...
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1answer
45 views

Making a portable 1A battery phone charger

I want to make a little battery-powered portable phone charger with 2x AAs that outputs 1A. I have seen similar USB powered battery chargers such as the Mintyboost but it only outputs 500mA. For 1A ...
-4
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0answers
8 views

Laptop won't start due to “electrical static” [migrated]

So I have an Aver s7 laptop, and when I turn it on the fan starts but it shows a black screen. Called support and they said it's out of warranty but it's a known problem with static electricity. ...
3
votes
2answers
62 views

Does my device need reverse polarity protection?

I'm developing a device with changeable AAA batteries running at 3V. Since the end user can change the batteries there is a chance they may be put in the wrong way around. The circuit basically ...
1
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0answers
59 views

Customized torch/flash light using a perfboard with an attiny

I am currently working on customizing the flashing frequency of a torch light (customized intervals between on&off). To program the individual frequency I have made use of an attiny 85 ...
0
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0answers
32 views

SLA charging circuit design

I got one more question about my car-dynamo-connected-to-bike project. My dynamo needs some juice to energize the electromagnets inside, so that's why I will include a small 12V 1.2Ah SLA battery ...
-6
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0answers
47 views

How to make use of things from the home for charging of smartphone in case of emergency? [on hold]

I am electronics guy. I have lost charger (AC100-240 Volts/ DC5.0Volts,600mA) of my smartphone Moto-G .As you can see there 5 types of connector pins My smartphone charger has connector pin no. 2 ...
2
votes
2answers
184 views

Are the silver terminal caps the only conductive parts on an AA battery?

With AA batteries, are the silver terminals the only conductive parts on an AA battery? That is, is the outpost ring around each terminal (part of the body casing?) conductive? I'm asking because I'm ...
1
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1answer
53 views

How can I power 7 IL151 5mm Clear White LED leds for a sculpture in a series circuit?

I am in the midst of planning a sculpture. The sculpture will require 7 IL151 5mm LEDs with a forward voltage of 3-3.5v . I have NO experience in electronics and I've been looking around and people ...
-6
votes
1answer
59 views

What happens if an electric circuit has 99% resistance? [on hold]

What happens if an electric circuit has 99% resistance? What if you let electricity come out of a the negative terminal, and only the tiniest bit of electricity comes back through the positive?
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1answer
22 views

Large voltage/amperage battery issues

I have purchased this lithium polymer battery (11.1V, 5500mAh), to power a robotics project. The project uses a Raspberry Pi, three continuous-rotation servo motors, a couple of LEDs and a Sparkfun ...
0
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0answers
58 views

Connecting a higher powered battery to a drone

I'm a programmer who's venturing into the robotics space. I see controllers like px4 that can be used for building drones. I can see it connects to a 12 V lipo battery and powers a ESC. The power ...
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0answers
38 views

How to choose a charger [closed]

I'm trying to make a quadricopter. I choose all my material but I don't find charger for my battery. Here it is : http://www.studiosport.fr/3d-robotics-batterie-lipo-pour-iris-p-4846.html I would ...
2
votes
1answer
75 views

-48VDC battery bank?

I was going over a request for a solar battery charger, and one of the points was a Low Voltage alarm (possibly meaning a LVD) to be triggered at -48VDC. This is a bit confusing as, to the best of my ...
-1
votes
1answer
51 views

Battery holder for protected 18650 battery [on hold]

When placing a 18650 Li-Ion rechargeable battery in its battery holder, everything is fine. The problem is with protected 18650 Li-Ion battery. There are protection circuits attached into them and ...
5
votes
7answers
319 views
+50

How to prevent a Lion Cell Phone Battery from Discharging over 20-30 years?

I'm planning to make a time-capsule that is to be opened 20-30 years from today. In this capsule I want to put a cellphone from todays time. With it I want to include the cellphone battery, which is a ...
0
votes
3answers
76 views

Will connecting two batteries in parallel increase current drawn in simple led circuit?

I have a resistor diode circuit that I'm powering with a 9V battery. The circuit diagram below is a simplified version of it. The real one has 4 LEDs, 8 resistors. I want to deliver 30mA to the ...
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2answers
72 views

Is it possible to combine multiple 5V USB batteries to power a Raspberry Pi for a long period of time (months)?

I need suggestions or help thinking this problem through. I want to battery power a Raspberry Pi with multiple USB battery packs (for a remote sensing application) with no need to do anything ...
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0answers
34 views

Standalone Ultrasonic speaker with preprogrammed frequency

I've been toying around with some Piezo speakers for my Arduino. Now I've been wondering if there is a way to remove the Arduino from the equation. It only serves as a power supply for the speaker. ...
-1
votes
1answer
66 views

Can I Charge a 12V Battery While It's In Use? [closed]

I have a Time-Clock (Where employee's check-in and check-out to track working time). Currently set up like this: 12V Adapter >> Time Clock So whenever that 12V adapter loses power, the time clock ...
0
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0answers
45 views

Ways to prevent shorts in a dynamic environment [migrated]

I have a small issue that is causing a lot of problems. I'm on an FSAE team and I'm running into an issue where our battery is consistently shorting between our positive terminal and our chassis. Our ...
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2answers
66 views

Fake nominal capacity of 18650 batteries? [closed]

I have bought, from different sellers, two 18650 batteries, but it seems that the capacity is much lower than the 4500 mAh or 3000 mAh label. In real life, it seems to be able to draw a constant ...
-4
votes
1answer
109 views

I want to charge my phone with AAs. How do I get that 5V output with max amperage (Would love to draw that 2.1A)

I was just wondering around, looking for how to charge my phone on the go. Because Wednesday morning I'll go camping. I just don't want to buy a cheap chinese power bank to charge my phone once. And ...
0
votes
1answer
29 views

How to attain a topping charge for a lead-acid battery?

Charging a lead-acid battery involves three stages: CC, CV, and Float. I have a charge controller which charges my battery at CC to the float voltage. I would like to add a device that would charge ...
-3
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0answers
23 views

Charging a deep cycle batteries [closed]

is it correct to simultaneously charge a deep cycle batteries using AC battery charger and solar charger controller?
-3
votes
1answer
68 views

Homemade battery power bank safe? [closed]

My micro-usb port on my phone is no longer functioning. So instead of buying a new phone or waiting weeks for a cheap battery power bank to come in from China (stuck for cash), I was thinking of ...
0
votes
2answers
62 views

What is the maximum Power that Smartphones charge with? 2400mAh? [closed]

I have seen chargers rated at up to 2400mA, so I wonder, whats the max that Smartphones will accept while charging? I ask because I want to buy a charger that is able to supply the absolute max my ...
0
votes
1answer
36 views

Switching High Voltage Battery from Series configuration to Parallel configuration for charging

I have a question regarding switching batteries from series to parallel to charge them. I have 36 modules of 1Sx11P Li-ion batteries connected in series. During normal operation they drive a car ...
7
votes
4answers
732 views

Capacitor connected directly with battery

This may be a dumb/begginer question, but I'm having trouble to understand what exactly happens when we connect a real capacitor directly with a battery. In my understanding, theoretically, when an ...
0
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3answers
38 views

Battery Wiring - 3 Independent systems with common ground

Background: Building a radio control wheel bot. Using a motor controller that recommends independent power supply for 1.) power to the controller and 2.) power to the motors. Also want a 3rd power ...
-4
votes
1answer
64k views

why Samsung mobile phone batteries comes with a chip like paper are they spying us? [closed]

yesterday I saw an WhatsApp message in that one person showing the Samsung phone batteries He remove the rapper and take out the black color thin paper or plastic sheet which is attached with the ...
0
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0answers
20 views

PCM batteries is necessary and regulamentations

I've a question about batteries PCM. Each battery should have a PCM? and where I can omit it? I see that battery charger IC have already charge voltage protection and charge current protections. And ...
0
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1answer
66 views

Are sealed lead-acid batteries safe to use indoors?

I have a small, 12V sealed lead-acid battery. I know regular lead-acid batteries can be dangerous to use or charge indoors, due to the fumes they release and the potential for acid to leak out or ...
1
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3answers
96 views

Using a 5V Optical Mouse USB Cable to Power a toy requiring 4 Size D batteries

I have a baby swing which requires 4 Size D batteries to get power. Here's a picture of such a thing - a human baby goes inside. Googling the information on Size D batteries, I found that 4 Size D ...
1
vote
1answer
36 views

MCP73844 Li-Ion charger

I am using a MCP73844 dual cell Li-Ion charge management controller to charge a pair of LIR2032 cells, which are rated at 45mAh. I have breadboarded the circuit according to the schematic in the ...
0
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1answer
50 views

12V Low battery indicator that has minimal power draw

I'm wanting to make a simple low battery indicator for 12V SLA battery - just an LED that lights when the voltage gets below a certain level. What sort of power would a circuit like this ...
1
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1answer
60 views

Newbie problem with transistor switching

First post, so I hope that I adhere well to all the rules. I couldn't find any other posts that could help me, so here's my problem: I am trying to build a simple transistor switch with a 3906 PNP ...
0
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0answers
33 views

PWM lithium-ion charger

I want to make a custom lithium-ion 18650 standard cell charger as I will be charging 100s of them (recycling old laptop batteries). Base on my research, lithium-ion cells use constant-current, ...
0
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0answers
29 views

Converting 12V DC to 7.4V DC [duplicate]

What i'm trying to do I would like to power my DSLR Camera using an external PSU PSU - 12V DC - 21A Camera's battery - ...
0
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2answers
81 views

charging battery directly from a source, what could go wrong?

I have a 100A lead acid deep cycle battery and also have a car's 12V 100A charger (alternator with AVR) At 1500RPM the alternator will produce nearly 100A.. and the battery is directly connected to ...
0
votes
1answer
47 views

Automatic distinction between PC-USB and Wall Adapter-USB

I want to ask if it's possible and an advice on how to make an automatic distinction between an PC-USB port and Wall-USB adapter. I've a battery charger IC (for example ...
2
votes
2answers
87 views

Good Batteries for (way) Sub-Zero Temperatures

I am building a PongSat and I need some batteries that can withstand the temperatures found at very high altitudes. The pongsat is planned to go up to around 100 km altitudes where the temperature is ...
0
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0answers
46 views

5V USB Input and Output for Battery Charger

I am looking to create a 5V input 5V output storage device (kind of like a portable phone charger) but I am struggling to choose a battery which is suitable. The device will be used for mobile device ...
-1
votes
1answer
59 views

Current consumption calculation and also battery life calculation [duplicate]

I'm a newbie, I need to know how to calculate the current consumption of circuit and also how do calculation of the battery life according to the circuit's current consumption? I'm using Li-Po ...
2
votes
2answers
87 views

Low battery detection

I'm using a power boost to convert a 18650 battery to 5V: How to detect low battery (i.e. battery voltage under a certain threshold), and send this information to a microcontroller? (I'm currently ...
0
votes
0answers
21 views

charge controller not disconnecting at full

When testing batteries and charge controllers I stumbled into something, this is what I found: 12V 100A battery charged using solar system with a charge controller in between, at 13.4V or ...
0
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2answers
91 views

low voltage battery disconnect from regulator

I am regulating a lithium ion battery to 3.3V and I want the regulator output to shut off when the regulator can no longer supply 3.3V. I am having trouble finding an IC that would do this, and this ...
-2
votes
1answer
51 views

Battery charged over USB and powering DC motors

I need help with figuring out how to power DC motors in my project. I need to power two 12V DC motors (they are connected in series) that will be controlled with momentary switch. The idea is to have ...
-1
votes
1answer
43 views

Testing accumulator usability by measuring its short circuit current, why it doesn't work?

I've experimented a little bit with some of my old, rechargeable batteries. (They "slept" around 5 years in a cabinet. I've long forgot their previous charged status.) What I did: I've measured ...
0
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2answers
89 views

Are there any battery chemistries that can be fabricated at home?

My question is simple. How hard it would be to fabricate a Battery of customized shape say of 30cm x 30 cm x 0.5 cm that can be fabricated by DIY without requiring any specialized/ hazardous chemicals ...