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).
491
questions
-1
votes
0answers
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 ...
0
votes
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 ...
0
votes
0answers
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 ...
2
votes
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 ...
1
vote
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 ...
1
vote
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. ...
0
votes
0answers
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 ...
1
vote
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 ...
0
votes
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....
0
votes
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 ...
0
votes
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. ...
4
votes
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 ...
3
votes
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 ...
13
votes
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, ...
1
vote
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 ...
0
votes
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 ...
0
votes
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, ...
9
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
-1
votes
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 ...
0
votes
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. ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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 ...
2
votes
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 ...
0
votes
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 ...
0
votes
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 ...
-2
votes
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 ...
1
vote
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.
...
0
votes
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 ...
1
vote
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 ...
0
votes
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 ...
