Questions tagged [battery-operated]

Involving or pertaining to a circuit or device that is intended to be operated with cells or batteries (as opposed to mains power, for example).

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52 views

Is it possible to use a mobile phone without a battery? [on hold]

I have a spare phone (galaxy S2, but I think this should be relatively independant of that) with a completely dead battery and im trying to figure out a good way to use it. I tried the way where you ...
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2answers
65 views

How to heat an e-cigaret coil

I am working on making my own "mod" for an e-cigaret (A mod is the device that controls when and how much the coil is heated up to) I have read a lot about it during the last couple of days, so i ...
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61 views

Motor driver powered by PSU instead of battery [duplicate]

I am about to use a motor driver in a project (MDDS30 by Cytron) and I was going to power it using a 12v 11.5a PSU. I discovered that the manufacturer warns against using a PSU, and that it might ...
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3answers
113 views

Real thing or just misinterpretation? Rotating batteries to make TV remote work

When TV remote isn't working, I rotate the batteries in the remote in their place and it begins to work. I don't see any kind of deposit between the batteries and the contacts. Rotation of battery ...
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1answer
63 views

Does a CR2032 take damage when connected to a 5V rail?

I've seen applications (Nintendo game cartridges, for example) that uses a coin cell battery for backup power to some RAM-chips (for savegames). When the ordinary 5V is gone, the battery takes over ...
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2answers
144 views

Do Duracell AAA batteries have internal short circuit detection?

I was shorting a Duracell AAA battery in a SAFE area with proper precautions. After 2 minutes I disconnected the circuit and measured the voltage, it dropped from 2.8V to 2.6V and the battery was hot. ...
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47 views

Is there a circuit that conserves energy of multiple power sources?

Say I have several batteries. To start all the batteries are "dormant"; there is no current running through them. Starting with the first battery it runs current through it until it dies, wherein the ...
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1answer
81 views

Measuring battery voltage and impedance

I have been trying to figure out how to properly measure battery voltage for a few days. The more I read, the less I understand. I know there are many questions like this out in the internet and I ...
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4answers
69 views

Reverse polarity protection for battery powered application

Im designing battery powered application and need reverse polarity protection. My system specs: 4.5v(3x AA batteries) in and system running on 3.3v. Im using MCP1711T-33I/OT LDO to convert 4.5v to 3....
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3answers
92 views

Wind turbine charger controller

I need help on my design which includes a wind turbine, charge controller, battery and load. The question is, what will happen to the load if the wind turbine is charging the battery and while it is ...
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2answers
88 views

What is the peak current for CR, LIR and AA batteries?

I'm working on a project that requires low energy consumption. In standby mode, it will consume about 11uA. However, when it starts working (it will transmit data in RF), the current goes up to 121mA. ...
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1answer
129 views

Do high and low side labels on bidirectional logic level converters matter?

Logic level converters like this one from Sparkfun have high side and low side labels on them. Now i have an application where I think I need to shift logic levels but the high side and the low side ...
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1answer
64 views

Rectifying reversible polarity battery with minimal power loss

I'd like to build a battery-powered DC power supply that will accept a single-cell battery in either polarity (i.e. it doesn't matter which way you put the battery in). I'm thinking of using the ...
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4answers
2k views

Does it matter if a fuse is connected to the negative or positive terminal of a battery?

I am currently going through the conundrum of where to place a fuse in my DC battery-powered circuit to protect the circuit components and the DC battery. I've been googling for a definitive answer, ...
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1answer
62 views

How to power a 10-watt electric circuit without grid connection in cold countries? [closed]

What options do we have for powering electric circuits without access to electric grid? For instance, to power a 10 watt LED lighting at night? The motivation to the project is to add some lighting in ...
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1answer
99 views

Noisy op amp buffer

I made an op amp buffer using a TL071 for my guitar but it is very noisy. The circuit is a simple follower. Originally I had no feedback resistor but I added it later in case it decreased the noise ...
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1answer
37 views

Voltage regulator STBY & OFF - whats the difference?

I am looking at MAX883 voltage regulator and from the documentation is not very clear whats the difference. It says this about pin OFF: In this mode, the pass transistor, control circuit, ...
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10answers
3k views

Would a 7805 5 V regulator drain a 9 V battery?

Doing some DIY as a hobby, I'm making a small humidity-temperature radio sensor. An ATmega328 is reading from a DHT11 sensor and then transmitting data to a Raspberry Pi by an STX882 radio ...
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1answer
65 views

Combining power input and USB data port for a Raspberry Pi Zero (W)

I am attempting to design some peripheral circuit around a Raspberry Pi Zero W for a portable project. It will be powered by a lithium battery. I want to bring out the USB port of the Pi; I also ...
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0answers
56 views

Multiple devices on 1 battery

My current project is a green lantern minigun prop. I 3d printed it already, im just working on the electrical end of things. I have a 12v drill motor that im using to spin the barrels. also in that ...
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1answer
69 views

Battery is 12 volt and motor is 3.7 volt…will it work?

I have a battery that says it has a working current of 4.6A and rated voltage of DC 12V I need the battery to power a motor for a fan that says it has a voltage of DC 3.7V Will it work? What will ...
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0answers
10 views

Double A battery & lithium battery charging way

I do have some question regarding the charging input for nimh double A battery & lithium battery. Is it possible for my 7.4volt lithium battery charged with 8.4volt 2Ampere charger? Any idea on ...
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0answers
74 views

Proper capacitors for ESP8266-12F?, resetting at high current peak

When using the ESP8266-12F on a PCB I designed myself it keeps resetting after a high current spike of another module (Sim800L). I ofcourse tried to solve this using capacitors but I seem to have made ...
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1answer
62 views

What is the cost of converting 12V (lead acid battery) to 220V and back again to power 12V appliances?

I have a small house measuring ~ 8m x 4.5m. It is in Indonesia and power outages are expected daily. Probably the daily power outage is on average less than half-an-hour, but sometimes the outage can ...
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0answers
29 views

Mountain Bike Light Bar 18650 battery pack

I have a 6 Inch LED Spot Mini Bar Light which is used for vehicles, it uses 12-24 V and is rated at 18 W of power. I have some 18650 batteries which would work perfectly for this project. What would ...
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1answer
70 views

How much battery power for LED and how to make it flicker [closed]

I am trying to figure out what configuration of battery(ies) I need to power this LED. I am only using one (specifically the warm white 1-up). I am also looking to make it flicker like a candle with ...
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1answer
76 views

Circuit to save one battery when another battery is present

I have a battery powered system and I want to preserve the test batteries during setup and calibration. I want the system to use the setup batteries if they are present and use the test batteries if ...
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0answers
53 views

Raspberry Pi wake-up and battery power circuit

I am working on a Raspberry Pi (3B plus) project that - at times -needs to operate on battery power, and on external power whenever available. The RPI needs to operate only when a dedicated sensor ...
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4answers
69 views

Should I include over-voltage protection for a 3.63V max device using a Lithium-SOCl2 3.65V battery?

When designing an ultra-low-power device that is powered by a primary lithium battery, is it necessary to include over-voltage protection? Specifically, I am using a Microchip (Atmel) SAML21J which ...
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2answers
89 views

Powering a servo with 9V battery and other questions

I'm working on a small project. I want to make an internet-connected dog food dispenser to attach to my dog's crate so I can dispatch a network command remotely to dispense it. I have a Raspberry Pi ...
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1answer
48 views

200AH lead acid battery

I have a 12V 200AH lead acid battery and I want my load be a power resistor and a bulb. Does the batter draw current based on the load resistance? so meaning the current that will be drawn in this ...
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2answers
66 views

Why can't I replace conventional batteries with rechargeable batteries everywhere?

In two cases, I experienced that a device does not work, or does not work correctly, with rechargable batteries, while one-way batteries do the job. Can that be, and if so, why? The two experiences ...
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1answer
106 views

3.7V to 5V step up not providing enough current

I'm trying to power up a circuit that consists of an Arduino Nano, 3x 3W stereo audio amplifiers (PAM8403), an audio player module and 20x RGB LEDs. The power source is a lithium battery 3.7V 500mAh. ...
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0answers
37 views

Charging Voltage of Lead Acid Batteries

I recently installed a solar ups and it has been charging the batteries all the time. I have two 12v 230ah Batteries (lead acid tubular) in series and my solar charger software says that it is ...
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2answers
49 views

What determines if a battery is charging or discharging in a circuit?

I have a basic understanding of DC circuits from high school and university physics courses, but those courses only covered circuits that discharge batteries. I'm trying to build an rudimentary ...
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1answer
96 views

Where do I place the on/off switch in a multi voltage circuit?

I've got a simple Arduino setup where I need to supply a 3.3V Arduino with adequate power - and at the same time provide higher voltage to a sensor which needs 5V. The Arduino is powered by bypassing ...
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1answer
155 views

Single Cell LED boost Converter

I am planning on powering 10 white LEDs (LUXEON 3014) from a single AA rechargeable battery with Vin min=0.9V, Vin max=1.4v VLed=2.8v @ 23mA so total Vout for 10 LEDs Vout=28v, iout=23mA I found this ...
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0answers
48 views

MCP73831 stat pin current

I'm trying to implement a bi-color LED connected to a Microchip MCP73831 battery charge management controller, so I can switch between red and green LED output. Currently my circuit is mixing them ...
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0answers
43 views

LM4890 amplifier and CR1616, how to improve power consumption?

I'm a hobbyst trying to design a simple circuit for amplifying the PWM audio output of an ATTINY85. I'm using an LM4890 (1W amp) and a 1W microspeaker. The problem comes when I supply 3V with a small ...
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0answers
63 views

How can I connect many brushless motors to a big battery pack instead of using a separate small pack for each motor?

Usually brushless motors comes with indications on how many batteries you can connect to them, it is common to to see 2x3 battery packs where each battery provides 3.6 Volts or so to power a single ...
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0answers
20 views

Mixing Reverse Polarity Protection PMOS with a Piezo Element

I have a circuit that powers some leds when vibrations are detected. I am trying to integrate a PMOS for reverse polarity battery protection. When the PMOS is present the circuit simulation fails as ...
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0answers
62 views

Ultra low power battery

I am currently in the middle of a project and I am quite unsure of what type of battery and battery charger I should be using. To be honest I have never worked with battery or battery charger yet. In ...
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2answers
337 views

Battery Voltage Monitoring

I have designed a simple battery voltage monitoring circuit to monitor a 3.7V Li-Po battery. My microcontroller (ESP32) uses a 3.3V supply. simulate this circuit – Schematic created using ...
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2answers
45 views

Motor controlled with a solid state relay not starting

We have a solid state relay controlled by a Raspberry Pi, The relay is interposed o the negative wire between a 11-12V battery and a motor. If I measure the voltage before entering the relay, it is ...
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0answers
108 views

Any Issues Getting BeagleBone Black Wireless to run off of LiPo with Diode Fix?

This helpful question pointed me into the right direction for powering the BBB with a 3.7V LiPo battery. However, as this answer demonstrated, I won't be able to give the WiFi/BT module power in doing ...
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1answer
88 views

How to measure battery capacity?

I hope this is not off topic. Consider I buy brand new 12V battery. Normally, will be 13.8V when it fully charged. According to the info written in the cover, it capacity is 42Ah. After used for ...
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1answer
128 views

Battery Power Source for Wireless Router & Modem? [closed]

I only have access to electrical power via a generator for now, and need to continue to power the wireless router & cable modem even when the generator is out for a good part of the day or night. ...
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2answers
129 views

Need a solution: Why does the battery voltage drop for custom PCB?

I have a custom PCB to control a solenoid or DC motor. Input voltage 6-7 volts with 4 batteries in series. I have a few questions: Why does the voltage drop by 1V to 1.5V when the switch is pressed ...
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2answers
88 views

Do Battery Powered devices require bulk cap at power input?

I am in the process of designing a +5V power supply for a hand-held 2xAAA powered device. When using TI's webench simulator tool to simulate a switcher power supply that I am considering, I noticed ...
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1answer
85 views

Variable output from Power Bank (24W = 12v * 2A and 5.4W = 9v * 0.6A)

I started with trying to find 2 UPS for 2 of my routers with the following input specifications: 12v 2A 9v 0.6A I realised that buying 2 power banks will be economical than buying 2 UPS for the AC ...