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).
6
votes
9answers
800 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
0answers
29 views
Appropriate Battery [closed]
I am currently developing a device that requires 5+ A current load at 12V. Now, I want it to be portable and rechargeable. What appropriate battery should I use taking into account the:
a) ...
0
votes
0answers
14 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 ...
1
vote
0answers
66 views
Creating a 3x18650 cell pack in series with 4 in parallel
I am going to create a 3S4P pack with some 18650 cells that I got from some lightly used laptop batteries.
Using: 8x Samsung ICR18650-22E and 4x LG LGABC21865
After doing some research I found that ...
0
votes
0answers
52 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
63 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
54 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
59 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
26 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
69 views
How much battery power for LED and how to make it flicker
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
74 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
46 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
71 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
43 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
63 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
93 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
27 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
47 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
91 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
148 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
36 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
38 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
60 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
17 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
60 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
223 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
37 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
82 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
65 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
65 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
121 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
84 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
70 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 ...
0
votes
0answers
51 views
“lithium for buffered usage in UPS”, or floating-charge lithium accumulator
For lead acid there are typically two paradigms of charging (or use-scenarios).
First one is deep cycles, when you exaust 40-60% of capacity (not less than 12.4V), then charge it to 14.4 with ...
0
votes
1answer
105 views
How to power two motor drivers and Raspberry Pi with one LiPo battery?
apologies in advance for the lengthy question.
I'm working on creating a remote controlled rover. It is controlled by a raspberry pi, and driven by two MDD10A REV2.0 motor drivers (one for the left ...
1
vote
1answer
78 views
Battery charger/discharger using N mosfet only
I want to make a battery charger discharger with an arduino, to be able to plot graphs. And afaik N mosfets are better in terms of Ron and cheaper and easier to ...
0
votes
1answer
109 views
Avoid fire on a battery-powered device [closed]
I was trying to repair a battery-powered electric razor when I suspect there was a short-circuit.
The device started heating and it began smoking a bit so I took it and put it in a bowl full of water....
0
votes
2answers
163 views
Calculate the Li-ion battery remaining capacity
How can I calculate the remaining capacity (exact or approx value) of a Li-ion battery by measuring its voltage. The battery is connected the load and i know only the battery voltage and the value of ...
11
votes
2answers
1k views
How much current can lead acid batteries safely supply?
I have a motor I wish to drive with an 18V lead acid battery. The motor can draw quite a lot of current when stalling and I am worried of overdischarging the lead acid battery. Unlike LiPo batteries ...
0
votes
2answers
75 views
Buck Boost Battery 3.6V (Lithium-thionyl Chloride) to 5V
I hope this question has not been asked and it's not as far as I have seen.
I am developing an IoT project which uses almost no current (< 100uA) when sleeping and up to 80mA when running. The ...
1
vote
1answer
76 views
Power supply question in regards to powering 400 LEDs
I have WS2812B LED strips, that has 144 LEDs per meter. The ratings are:
43W/M .3W/LED
.06A per LED
Input Voltage of 5V DC
The recommended power supply stated by the website is 5V DC and 10A for 1 ...
1
vote
1answer
58 views
How to fix 4AA battery pack holder
I have a battery pack holder. I have tested the batteries with my multi meter. It appears that the ground and power wires on my pack holder are not working. Does this mean that the wires are not ...
0
votes
1answer
135 views
Battery advice re cooking equipment
Please go gentle as I am a novice at electronics/battery issues.
I am hoping someone with a much bigger brain than me can answer this question...
Is it realistically possible to power a 1200W ...
0
votes
1answer
48 views
Reducing voltage for increased current through wire
I am wondering, if I reduce the voltage going through a specific sized wire, can I therefore increase the current? I am creating a series-parallel battery bank and it will output 7.4 volts at 75 amp ...
2
votes
1answer
83 views
DIY transformer (toroid) waveform
Update
Ok, it may be related to the adhesive I'm using to glue the toroids on the 3D prints.. I'll wait till tomorrow for it to cure and test again..
I'm trying to build a portable/battery ...
2
votes
2answers
214 views
(Reasonably) accurate 1Hz clock generator
I would like your advice on components before I purchase anything.
I am going to make a digital 24hr clock using probably JK flip flops/multiplexors with 7 segment displays. But it must be battery-...
2
votes
1answer
63 views
Ultra-long shelf life battery [closed]
For those who like their questions to be 100% practical and serious, please look away now.
I've just watched "Raiders of the Lost Ark", which got me speculating about how to bring the booby-trapped ...
2
votes
3answers
132 views
why is this microcontroller brown-out level detection at 2.6V and 3.4V
The default brown-out detection level for the ATmega32u4 is 2.6V (typical) in the range of 2.4V to 2.8V. The table of possible values:
...
