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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Grounding accessories in an automotive (~12V) system

Have seen similar questions but not found a definitive answer, so here goes. Split charge and leisure battery fitted in my Volkswagen T5, and I want to run a USB charger, cigarette lighter charger and ...
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2answers
50 views

The actual battery discharge time through LED?

Initially I used a 9 V 170 mAh battery for powering a 3 W LED which was rated 9 V and 333 mA. Calculating the power consumption of the battery based on how long the LED light will last came to around: ...
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3answers
52 views

Wiring question

I would like to take a 96 LED Infrared light (12v 2 amp) and cut the cord and add a battery wiring harness. Can I just add two 9v battery wiring harnesses to it? I'm pretty confident that I could add ...
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1answer
49 views

How can I avoid using different batteries to power different components in a circuit board?

I am looking to use MOSFETs as a switch to run a motor and we ran into a slight problem with the power supply to the circuit board. The main batteries we would like to use output 14.4 V nominally. ...
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1answer
46 views

Battery Charger Drawing Too Much Current [on hold]

I am working on a project where I am switching between a solar panel and a 20 volt, 5 amp AC to DC wall adapter to charge a 12 volt lithium iron phosphate battery. I am using a Morningstar Duo solar ...
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1answer
71 views

Angry birds spinning toy working

I recently purchased the Angry birds spinning toy which works like this. The hand crank basically rotates and from the power generated,Dissecting the product into various parts, I came across certain ...
3
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1answer
81 views

CR2032 vs LIR2032 vs Capacitance Battery

I have an Android TV Box device that does not retain the date and time. Turns out there is not real time clock backup (RTC battery). There are 3 options to solve this. Capacitance battery CR2032 ...
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1answer
68 views

Light LEDs with NIMH Batteries

I need to drive a 3 W LED (Forward voltage 12 V, Forward current 0.2 to 0.3 A) using NiMH Batteries( 1.2 V, 2700 mAh ). As the supply voltage should exceed the forward voltage of the LED, I am ...
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1answer
103 views

Odd failure mode for AAA battery

I purchased a flashlight that came with 3x AAA cells. These are branded with the flashlight brand, labeled as Alkaline (Mercury and Cadmium free), LR03 AM4. Made in China. I am dubious of the Alkaline ...
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0answers
24 views

Use wall adapter to replace 8 AA battery pack [duplicate]

I'm fairly new at electronics as a hobby and would like to use a wall outlet adapter instead of a battery pack. The instructions say to use an 8 AA battery pack and I would need an equivalent power ...
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0answers
88 views

Car ECU damage due to lightning strike

The car Engine, ABS, combination meter ECUs were found to have damaged. Further inspection revealed that the voltage regulators in the modules were burst/ shows burn marks..is it Possible that a ...
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2answers
110 views

How many batteries are required for a 3.5 kVA inverter?

I am planning to buy a 3.5 kVA small industrial inverter, but I am not able to figure out how many batteries are needed for that. Please anyone help me out with details.
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52 views

Laptop battery pack rebuild; what cell discharge rate?

Currently I am looking for eight new 18650 battery cells to rebuild my iBook G4 (A1055) battery pack. Because I can't find for what discharge rate the original cells are rated, I'm not sure which ...
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2answers
57 views

Why is it that current pass from charger to battery while both of them have the same voltage?

Why is it that the charger stops charging when the battery is full? I answered myself that the battery is like a variable resistor and when it empty the resistor is low and when it full of energy ...
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0answers
44 views

How to design a circuit checking if 12V car battery is charging?

I have a small solar power charging module and load balancer, that takes input from a solar panel, has connectors for a car battery (12V) and output terminals. These things are pretty common on thing ...
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1answer
37 views

24v vs 48v solar inverter

I have 4 batteries of 150AH each. Earlier these were connected as series to 48v solar inverter of 3000 Watts, now as that old inverter is dead and I need to replace it with new one. I want to know ...
0
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1answer
44 views

Practicality of using different types of battery cells to avoid DC-to-DC conversion

One problem with solar systems is the need for high-efficiency DC-DC converters. For example, if lead-acid 12V storage batteries are used, then the user is faced with the problem of down converting ...
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1answer
26 views

How to connect both a bluetooth receiver and a amplifier to the same power input?

Dear users of this forum, I am new to this so I apologize in advance for any rookie mistakes. I am building a portable speaker of which I connected the speakers and the amp already. I am looking for ...
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3answers
81 views

Get -50V to 50V range from battery output

I have the following problem: on the system which is battery-powered(4S1P Li-ion battery, 14.8V) I need to create outputs from -50V to 50V. The system has microcontroller on-board. I am baffled on ...
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1answer
69 views

Low voltage drop regulators?

I am building a battery backup system for a dc appliance that runs on 6v. I have a 6v sealed lead acid battery to serve as the backup source. However i read that a lead acid battery at full charge ...
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1answer
75 views

Ni-MH battery voltage [duplicate]

I have a battery pack of 8 Ni-MH 2400 mAh cells connected to a load that draws ~700 mAh (a Raspberry Pi Zero, display, WiFi dongle, USB hub, and a wireless keyboard dongle). I want to add a led that ...
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0answers
46 views

Relation between battery cell capacity & internal resistance

I'm trying to design a large battery pack, that should provide a given amount of power, with a reasonable amount of heat dissipations. To do so, I have three degrees of freedom: indidividual cell ...
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2answers
61 views

Help powering an old heater control board im trying to reprogram

Not photo of my specific board. I got 3 old universal controller board's , I'm attempting to reprogram them to learn hardware hacking. But i not quiet sure what would be the best method of powering ...
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3answers
64 views

Does LiPo4 battery amperage output increase as voltage decreases from 4.2V to 3.57? I'm trying to size up a diode [on hold]

I'm trying to determine the max amp output of a battery pack that has 28 cells in it. To be more specific towards what I'm doing: I'm trying to size up a diode for the charge port; the battery charges ...
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1answer
81 views

Lithium-ion battery Internal resistance myth

I am making a battery tester, lithium ion battery for particular. and I want to measure the internal resistance, but after testing few cells, I am skeptical for my results, since most of them, new or ...
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1answer
89 views

Why 12v batteries but not 110/240 corresponding with the mains?

I have a basic curiosity question while I trying to learn/figure electrical "things" while I trying to size my UPS. I know that an UPS will convert power from mains (240v in my case) into 12v battery ...
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2answers
67 views

What's the C rating for NiMH batteries? [duplicate]

On most hobby Li-ion packs there is a prominently displayed C rating (typically 20 - 35), which tells you how many amps you can draw from it, in a multiple of the capacity. I have never seen a C ...
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1answer
36 views

(External Battery) If i have Portable Charger that has a capacity of 50,000 mAh and

4 ports with 2 amps, 2 amps, 1 amp, and 1 amp that can charge 4 phones respectively. How long will the battery continue to charge these phones, assuming they are pulling the largest load possible? ...
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29 views

why the BMS gets hot on a 24v 18650 battery pack

I built a 24v battery pack for e-biking using a BMS I found on ebay here is the link: http://www.ebay.com/itm/131574426689?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT I'm using ...
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3answers
148 views

How many amps can a car battery supply?

Googling this hasn't given me much information. I've heard numbers ranging from 30A to 300A. My question isn't how many amps a car battery does supply in normal operation, it's how many amps I ...
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3answers
70 views

Multiple source Smartphone charger pack

I am in no means a electrical engineer or student but i dabble. I have a project to make a BIG smartphone charger using multiple 1800mAH batteries. you can choose which cell to use and charge via a ...
2
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1answer
71 views

Flat coil inside rechargable lithium battery

Take a look at this de-labeled smartphone Lithium-Ion battery: What is the coil used for? Possibilities I thought of: Wireless charging - unlikely because the outer metal foil would screen the ...
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1answer
84 views

mAh and Wh ratings not matching with voltage of device

I was under the impression that Wh = Ah * V I have a 20000mAh battery charging device for my phone but am confused about the information provided by it on the side. It claims to have a 5V output (3....
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0answers
50 views

An SoC pulling the power source voltage

I'm trying to power a SoC with a battery as in the figure below. The SoC in question is the WeMos, based on the ESP-8226. simulate this circuit – Schematic created using CircuitLab When ...
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1answer
30 views

Standard/Specification for regular alkaline batteries

Where can one find the standard specification for regular alkaline AAA, AA, C and D batteries? I mean, I know that different suppliers must have different battery capacity/property but there must be ...
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2answers
49 views

High current draw at start up of DC motor. How to understand if the battery can withstand it?

Suppose I have a solar powered plant like this one below: simulate this circuit – Schematic created using CircuitLab The solar panel charges the batteries and, when needed, the power is ...
0
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1answer
38 views

How to make inverse switch with bc547?

I want to make a circuit where the power to mcu switches from mains transformer to dc battery when when mains power is not available. The basic concept is to use a transistor to stay open circuit to ...
0
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1answer
64 views

CR2032 alternative for higher current [closed]

I'm designing a small battery powered circuit which will draw around 50mA for a millisecond every couple of seconds. I was planning on using a CR2032 coin cell but have recently learned that a coin ...
0
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1answer
54 views

The battery voltage and current relation

While a battery is discharging ,its voltage is decreasing , what happens to the the current? Does it decrease ,increase ,or stay constant?
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21 views

battery charger

is it be advisable to connect two deep cycle batteries from the same brand(both 12V 52AH and 55AH). will a 3AH difference affect my system?,should i want to make a 24V volts series connection. The ...
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0answers
35 views

What is a good melting point for a lithium battery contact fuse?

Tesla uses a fuse on every battery for their cars, and many fusible alloys melt from 50 to 90 degrees. because the fuse is welded onto the battery it wouldn't matter what the fuse current was, you ...
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1answer
40 views

Usb battery charging

I am designing a system which has a mcu (with usb peripheral). The whole system is powered by a 18650 Li ion battery. Now, imagine I am charging the battery by plugging the usb to a computer usb ...
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0answers
12 views

Why do I connect the positive and the negative to the battery on a boat? [migrated]

My trolling motor for my boat has a black and a red connection. The red goes to the positive on the 12 volt battery. The black goes to the negative on the 12 volt battery. Could I connect the black ...
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3answers
89 views

Does a helicopter battery drain when it is “off” but attached to a battery hot bus?

I'm reading about the DC Power System for a civilian helicopter. It shows the following diagram for when the battery is off: However, it shows that the ...
0
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1answer
36 views

Detect battery/cell's charge

I am building a portable device with Raspberry Pi and powered by 3 AAA batteries in series. I am trying to create a battery indicator with a LED: Green = Full power Orange = Half power Red = Low ...
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1answer
27 views

Inequal discharge across battery cell

I am looking into building my own battery management system, and I am beginning to understand the concerns of overcharging/discharging, overheating, and equal use of each of the cells. I am planning ...
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1answer
42 views

Two 12 volt batteries lowering reaches power

I just added an extra deep cycle 12 volt battery to my camper. I used half inch 15ft (or so) wire to connect the positive to the older batterys positive and the same for the negative. My older ...
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1answer
51 views

Can I put a 4500 mAh 18650 li-ion battery on a 2600 mAh powerbank?

I recently bought a mobile phone powerbank without realising that the battery wasn't included on the kit. So now I need to buy a 18650 li-ion battery and I found one that has 4500 mAh. Can I put the ...
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0answers
31 views

How to charge a Tablet Lithium ion Battery outside the tablet (not connect to it)?

I would like to know what is the pinout of this battery (cf. the image) and to know how I can charge it outside the tablet (not connect to the tablet). Can we charge any kind of Tablet lithium ion ...
1
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1answer
38 views

What happens when wire touches only negative battery terminal?

Might be more of a physics question, but what happens when you connect a wire only to the negative (or positive) terminal of a battery, in terms of electron movement? Do electrons flow in/out of the ...