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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13 views

Czech RF10 Battery Help [on hold]

Need some help. I purchased a Czech RF-10 radio which has a battery box with Five Ni-MH "D" cells inside.. (see prc68.com) I would like to know how to recharge these batteries. Can I use a universal ...
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3answers
44 views

Calculating battery time giving its capacity and load

I am referring to the airplane shown here. The battery is said to have 640 Whr capacity (actually this is the discharge rate), the load being a 2700 W motor. Then the endurance is giving as 110 ...
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1answer
48 views

Charging 7.4V Li-Ion battery

I'm making a battery out of two 3.75V Li-Ion cells to go into a speaker system that powers an amplifier. I was wondering on the PCM, how many volts would be max to charge these cells? The cells I have ...
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1answer
114 views

How to make a battery draining circuit?

I have an air soft gun battery that needs to be completely before charging it because the charger does not have overcharge protection. Basically I have to time charging it. I would like to make a ...
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4answers
70 views

Replacing adapter with batteries?

I have some device with ac/dc adapter [9v, 500mA], and I want to replace the adapter with batteries. If I used [6 * 1.5v] battries, is that acceptable? do I have to worry about the max current of the ...
2
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2answers
77 views

Overcoming voltage drop in a battery

I want to use this battery for my Arduino Uno: ...
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1answer
37 views

Battery Voltage is not as it should be when connected to ckt

I brought 6F22 9V battery. One's output voltage became nearly 6 volt after some use.But when I connect it with a MCU ckt , It gives only 3.37V as output ( voltage tested directly from the battery's ...
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0answers
40 views

Constant current source to disharge battery [closed]

I would like to make a circuit to discharge a battery to 3.6v using constant current, but I don't understand how it should work. Can you give me a quick overview and general schematic for that. I mean ...
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1answer
33 views

Measuring smartphone's battery State-of-Charge during charging

I'm designing a mobile device that uses a Li-Ion battery. It is required to indicate to the user the State-of-Charge of the battery, similar to how it's done in smartphones. At first I considered ...
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3answers
128 views

Help my off grid solar system is driving me mad

Please can someone help me with this problem I'm having with my solar system? Ok I have 7 × 190w 24v panels wired in parallel, Coming down to a 80A MPPT charge controler which automatically selects ...
3
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1answer
67 views

What type of eye protection should you use with a battery tab welder?

There are a ton of youtube videos and websites about how to make a DIY battery tab welder - however none of them seem to have any information on what type of eye protection to use. I know that some ...
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1answer
37 views

Electric car charge depletion time? [closed]

I'm assuming these batteries are similar to or exactly like a capacitor? Also is there an equation to determine the charge decay rate based on usage and/or the time it stays still? If i wanted to make ...
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3answers
135 views

How to drive optocoupler with BJT properly [schematics]

Recently I asked a question about optocoupler: Shematics: optocoupler controls a transistor and doesn't work as expected I have one more question related to the topic. PWM input comes from the ...
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6answers
298 views

Is there any physical device called current source?

I have seen both current source and voltage source in many electrical circuits (in paper). When it comes real hardware battery can be considered as a voltage source. Then what is a current source ? ...
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1answer
37 views

Low Current Battery Montior Detail Question

I'm trying to design a circuit that will be running from a battery. I'm currently working on the part that detects the voltage and came across this question (and answers) here: It made pretty good ...
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1answer
50 views

High-current monitoring circuit

I have the following circuitry: Battery Supply => Current Monitoring Circuitry => DC Motors Battery Supply: 4AA NiMH batteries - 4*1.2V (1.5mAh * 4) Current Monitoring Circuitry: Max 4378 chip ...
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1answer
44 views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
2
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5answers
142 views

How to Choose a Battery

I would like to start off by saying I have little actual experience in electronics, so bare with me, and for all I know I could be way in over my head. Anyway... I was thinking of making a ...
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1answer
78 views

Can batteries be charged and discharged at the same time? And do they wear down faster when doing so? [duplicate]

Imagine batteries connected to a charge controller and a load at the same time. When the load asks for power, and the charge controller delivers power, there are three possible situations: P_in > ...
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2answers
78 views

What is the maximum safe voltage for 1.5V and 3.7V gadgets of consumer electronics?

I know that most electronics for 1xAA battery accept at least 1.1-2V and for li-ion 3.5-4.3V. But what is probable safe maximum? Can I use li-ion with 20ohm resistor or even without it for supply 1xAA ...
0
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1answer
76 views

Li-ion battery choose question

I am new to this forum and I hope you can help me with this. I want to build a small circuit that will have: an ATXMEGA ucontroler that uses all of its 5 USART and one bluetooth module. This circuit ...
2
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2answers
79 views

What is “current rating” in a battery implied by?

How battery limits current to the maximum level that is indicated in its specification? If V/R value is greater than maximum current rating then current through the device will be V/R or maximum ...
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2answers
97 views

Is it possible to run a photodiode plus op amp on a 3V battery?

Naive question here. I've been toying around with the idea of making a simple light meter. From what I've read, photodiodes generally offer the best sensitivity and accuracy (as compared to ...
2
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1answer
88 views

Designing an ultra-thin battery holder (CR2016)

We are designing a miniature electronic device and run into an issue. The suitable battery holders we were able to find are 2.6 mm thick. But the battery is just 1.6 mm thick. It is a huge difference ...
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1answer
78 views

Mysterious voltage drop then slows climbs back up when powered off

Ive built a simple circuit on some strip board, just a motor and a micro controller and LED and powered by 6 AAA batteries. The motor takes its power straight from the battery and the micro and LED go ...
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2answers
134 views

How to adjust output current on a buck converter?

I 'm planing to use a zinc–carbon 9 V battery to power up: the circuit that battery belongs to BeagleBoard-xM I 'm thinking of using a breadboard, in order to power up both circuits. ...
2
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2answers
114 views

How to power up BeagleBoard-xM using batteries?

I 'm looking for a battery solution to power up BeagleBoard-xM. Until now, I used a 5 V, 3.2 A AC/DC power supply adapter (2.1 mm barrel plug). I 'm thinking of using a 4 x 1.2 NiMH AA battery pack ...
2
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1answer
71 views

why do rechargeable batteries fail so horribly in high drain environments?

I've tried nicads and nimhs in flashlights and they always end up leaking. I know how spikes and memory work in such batteries, but why do such high drain applications cause such catastrophic ...
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2answers
66 views

Charging lead acid (car) batteries with a common ground

I have three identical lead acid batteries. All three batteries are on a common ground since they power different components on a same circuit. I have three independent "intelligent" chargers whose ...
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3answers
147 views

Li-Ion battery questions

After putting battery in freezer overnight (in ziplock bag to avoid moisture (according to sites battery loses >20% Capacity in >3 months to a year) Does the rapid heating up cause by turning phone on ...
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3answers
120 views

Sanyo battery: what 430MH stands for?

I have a SANYO NI-MH battery from my Oral-B toothbrush. I reads 430MH. Now I'm curious what does 430MH stand for? Im thinking its probably nickel–metal hydride if ...
2
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2answers
96 views

How to choose what voltage power supply to use?

I'd like to build a keyboard emulator, and I've found three links that detail the process: 1, 2, 3. Here's the rough circuit: The thing is, across the various articles I've read, people are using ...
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1answer
63 views

Prevent full startup when only battery backup applied

I have an ATMega328 running firmware that goes to sleep when main 5V power is removed and runs on a 3V backup battery instead. While in sleep, the watchdog timer wakes it up occasionally to keep a ...
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1answer
39 views

How does the battery and power adapter interfaced in the laptop?

How is the typical laptop's battery (multi-cell Li-Ion) and external power interfaced ? What all components go into designing that circuit ? The required behavior is: When power cable is connected ...
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1answer
37 views

GSM module working when powered by laptop via USB but keeps restarting when powered by battery

I am using a sim900 module in the following link and I connect it to my laptop using USB to TTL converter and the module works properly. But, when I connect the same module to 9V DC battery the module ...
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1answer
92 views

Connect batteries with different voltage in series

simulate this circuit – Schematic created using CircuitLab I have two 9V batteries connected together in series. I also have a battery connected in parallel with total voltage of 6V and ...
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1answer
31 views

Need to know battery configuration for a 250 watts inverter [closed]

I have a 12 Volt inverter which have ability to produce 250 W output. I would like to purchase a battery for this. can any one tell me the configuration of battery ? eg: Minimum AH
2
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2answers
102 views

How to detect how much battery power is drawn?

I'm programming a small device using a microcontroller. I'd like to optimize it to use less battery. How can I detect how much power uses over time as I run it through some tests? Based on the ...
2
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3answers
428 views

What to plug in first to usb charger when charging: wall outlet or cell phone and why? [closed]

I asked this question on Physics StackExchange but was advised to ask it here. When I charge me cell phone or notebook or whatever device what should I plug in first? Should I at first plug in usb ...
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2answers
74 views

What to plug in first to usb charger when charging: wall outlet or cell phone and why? [duplicate]

When I charge me cell phone or notebook or whatever what should I plug in first? Should I at first plug in usb charger to the AC wall outlet and only then to the cell phone or vice versa ? What are ...
0
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1answer
71 views

Charge at 24v and discharge at 12v for battery system

Is my thinking correct. Below is a simple diagram of the concept I want to check. Is this: 1: Possible 2: Feasible? I.E are there any concerns or foreseen issues with this design? Edit:
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1answer
31 views

Atmeg16 USART communication problem

In my project, I use a atmega16 to send data to PC via USB to TTL converter at baud rate of 9600 and internal RC of 4Mhz. If I power the atmega16 using my laptop through a usb cable I can receive the ...
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3answers
78 views

Getting AC voltage from DC battery

When measuring the AC voltage across a DC battery (CR2032), and I am getting 6v. The DC voltage across it is 3.01 volts. I also tested on a 9 volt battery; again the same thing. I am reading about 20 ...
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2answers
87 views

Possible to charge one phone off another?

What's stopping the ability of charging a cell phone from another cell phone? If I were to create a crossover/patch USB cable and connect it between two phones or tablets, would there by any way to ...
1
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1answer
88 views

What is the difference between Pack- and Bat- on a LiPo Battery

I am trying to figure out how to use the TI bq34z100 to measure the charge in a 29.6v 8s1p 5.4Ah pack. Out of this pack I have A charge connector with + and - and a discharge connector with + and - ...
0
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2answers
137 views

Why does this mobile phone battery have 4 terminals? [duplicate]

Why do some mobile phone batteries have 4 terminals? I want to use a mobile phone battery for my project.
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2answers
43 views

Using Battery (li-ion) with higher capacity [closed]

Just got portable radio Ambient Weather WR-111B. It is using CR123A 3.7V/800 mAh rechargeable lithium ion battery. On ebay I see CR123A 3.7V for a different capacity than 800mAh: 1200mAh or 2200mAh. ...
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2answers
75 views

Calculating required power to run 2 modems in kWh

I am an electronics newbie. I have two modems at home. One is DSL Ethernet modem provided by DSL provider and other is TPLink wireless router. I see they have written Voltage and Ampere written on ...
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2answers
64 views

Can I use LIPO battery voltage checker for 12V lead acid battery? [closed]

Can I use the LIPO battery voltage checker to monitor voltage of my 12V 7Ah lead acid sealed battery? Currently I use a multimeter to check the battery voltage frequently as I am experimenting with ...
0
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1answer
50 views

Best battery configuration

With this typical connection, lighting lasts for about 19h. With this arrangement lasts more? All batteries are rechargeable Ni-Cd