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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2
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2answers
179 views

Are the silver terminal caps the only conductive parts on an AA battery?

With AA batteries, are the silver terminals the only conductive parts on an AA battery? That is, is the outpost ring around each terminal (part of the body casing?) conductive? I'm asking because I'm ...
0
votes
2answers
68 views

Is it possible to combine multiple 5V USB batteries to power a Raspberry Pi for a long period of time (months)?

I need suggestions or help thinking this problem through. I want to battery power a Raspberry Pi with multiple USB battery packs (for a remote sensing application) with no need to do anything ...
-4
votes
1answer
104 views

I want to charge my phone with AAs. How do I get that 5V output with max amperage (Would love to draw that 2.1A)

I was just wondering around, looking for how to charge my phone on the go. Because Wednesday morning I'll go camping. I just don't want to buy a cheap chinese power bank to charge my phone once. And ...
-4
votes
1answer
93 views

Do I need an isolated DC-DC converter for this design? [closed]

Do I have to use isolated DC converters for that design or single DC SFDC CONVERTERS' Simple schematic for a LiFePO4 4 cells module balancer Expanded view of converters: this design is to use ...
0
votes
2answers
140 views

Step up converter (3.7V to 5V) that will also charge battery!

As a picture often speaks better than words, here is what I'm looking for (the yellow circuit on this picture): i.e. : a circuit that converts 3.7 V to 5 V when a 18650 battery (3.7V) is ...
0
votes
1answer
59 views

Switching Micro-controller from Adapter power to Battery [duplicate]

Currently I am running my micro-controller boards with power adapter(AC to DC). Now I am developing a system which senses AC power and sends me some signal when AC power is gone. The problem is I am ...
0
votes
1answer
67 views

Driving P-Channel MOSFET from MCU Pin While Running on Coin Battery

I made a circuit that uses the DMP2305U P-Channel enhancement mode MOSFET. I connected the pin of the PIC microcontroller directly to the gate pin of the MOSFET. The purpose of this MOSFET to enable ...
0
votes
4answers
89 views

Switching power supply 12V/3.3V for battery powered application with SLEEP mode

I'm designing a 3V3 PSU for 12/6V (lead) battery powered (outdoor) application. Supposed load is 70mA but I plan sleep mode (50uA) with periodic wake-up (ATMega1284P with 32kHz (RTC) crystal). It ...
0
votes
1answer
49 views

Issue powering Shop Vac with Car Battery (via Power Inverter)

I am hoping to run a shop vac off a var battery (this car battery will not be attached to a car). I am hoping to use this vacuum in a remote part of our yard away from any conventual power resources. ...
1
vote
1answer
158 views

Boost with LDO?

I'm working on a project that requires 3.3V from a pair of double AAs. I had thought that LDOs were always buck and if you needed boost you had to use a switching regulator. While doing some ...
2
votes
1answer
49 views

Battery powered project with multiple voltages

I am working on a project which requires three different voltage levels - Motor that can run at 7-12 V. Hall sensor that can run at 5-25 V. nRF24L01+ that can run at 2-3.6 V and AVR (arduino) which ...
0
votes
1answer
67 views

Can I connect Battery positive terminal directly to MCU ADC input Pin?

MCU is powered directly from 3 V battery and I am using ADC input of MCU to monitor the battery voltage to detect low battery situation. I have got good inputs on this site(I need to monitor the ...
0
votes
1answer
45 views

Circuit to put digital amplifier into standby when no audio is at inputs?

I am putting together a battery powered audio amplifier using the PAM8403 class D chip. http://www.diodes.com/datasheets/PAM8403.pdf It has an active low STANDBY pin which turns off the circuits ...
-4
votes
1answer
33 views

Battery Cell Properties [closed]

I have a pair of Bluetooth headphones with a 3.7v, 180mA battery cell. I am wondering if it would be possible to increase the battery cell by replacing it with maybe a 5v or 9v. However I don't want ...
0
votes
1answer
60 views

Stop earth from introducing noise to piezo circuit

I am currently prototyping a circuit which measures pulses on piezo-electric sensors; however, I seem to be having an issue with noise. When the circuit is battery powered (and therefore floating), ...
1
vote
1answer
54 views

Portable device shielding & ESD

I'm working on a portable battery-powered device with a shielded I/O connector for sensors, but I'm confused about how to properly ground the shield and ESD array. Here is a block diagram of my ...
0
votes
2answers
76 views

Figuring out battery life from amp draw?

I decided to take apart one of those cheap handheld fans. It takes 2AA Alkaline batteries. I wanted to hook it up to an arduino as a way to get into electronics, and I wanted to know what kind of ...
0
votes
2answers
128 views

High-efficiency blinking LED circuit

I'm an artist currently working on an installation piece that requires a little more engineering knowledge than I possess. In short, what I'd like to achieve is a 2 LED blinking circuit with battery ...
1
vote
1answer
85 views

Selecting the right battery type and capacity

Have a machine in mind which is intended to be portable (hence weight and dimensions is a constraint), has a miniature refrigerant compressor (like those of Aspen) plus a blower of nominal wattage. ...
0
votes
1answer
60 views

How do simple low power devices store setup when switched off?

I often come across battery powered items that store their state when switched off, particularly 'simple' items like LED bicycle lights (e.g. flash or solid light, changing each time it is switched ...
1
vote
1answer
79 views

Efficient power supply from batteries

I am still new to electronics and I am looking for a low noise and efficient way to provide 5V and 3.3V from AA batteries. My circuit requires 3.3V/200mA 10% of the time and less than 1mA the other ...
0
votes
0answers
68 views

First time enthusiast attempting to build a bottle glorifier with a single LED and battery for portability

I am attempting to make a bottle glorifier out of a single LED that will in theory last for a month without having to turn it off and run it off of some type of battery. That way i could change the ...
1
vote
1answer
72 views

Intel Atom board (DN2800MT) power supply, can I add battery?

After reading through 20-something posts about 'car/12V/power supply/computer' I've still not found a definitive answer to what I'd like to try here. If this turns out to be a dupe after all, my ...
1
vote
1answer
45 views

specific application of 9V battery pack substituted for a 9V power supply

I have a JamMan Solo XT loop pedal that is rated at 9V DC, 200mA. I want to make a really simple altoid tin battery pack. I'm checking with you guys because I don't want to damage the foot pedal with ...
0
votes
1answer
45 views

Zigbee low power mode when both devices are battery-powered

Does Zigbee allow low power mode when the communication is between 2 battery powered devices so that both can last longer on the batteries? I suppose typically there's a mains-powered host that would ...
0
votes
2answers
104 views

Help please! I need to give constant current to an LED from a Lipo battery

I'm trying to drive an LED from a Lipo battery. The useable voltage range of the Lipo goes from 4.2V down to 3.4V, and the forward voltage of the LED is 3.2V. With a resistor in series with the LED, ...
1
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0answers
66 views

Switching between power supplies with supply dominance selection

Following an earlier question Switching between power supplies - USB dominant After doing some more research with the given answers and after seeing switch between battery and usb power no ...
16
votes
1answer
3k views

Why do smoke detectors run off 9v batteries?

Is there a component that requires a higher voltage? Wouldn't they last longer on AA/AAA batteries?
1
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1answer
39 views

What are the main considerations for a battery operated project [closed]

I just wanted to know what are the major considerations to be taken into account while designing a battery operated project. What are the major optimizations to be done in order to improve battery ...
5
votes
3answers
929 views

Simple, efficient “breathing” LED circuit

I'm currently working on a small circuit, which I intend on running off a CR2032. The intent is to have the circuit last at least 2 weeks (the longer the better), pulsing a green LED every 3 seconds, ...
0
votes
0answers
97 views

Dual redundant 1.5V battery power system?

I'm trying to build an efficient way to connect two 1.5V alkaline batteries in a redundant configuration for my circuit. I only want one battery to be supplying power to the circuit at any given time. ...
1
vote
1answer
197 views

Beaglebone black gets shutdown signal when I move rc motors

I have a beaglebone black that I tucked inside an rc truck. I removed the radio control chip. Everywhere it had 3.9 volt logic I put in a 3.3v gpio control from the beaglebone. It works great I'm ...
1
vote
1answer
121 views

Nimh battery for Electric Bike

I've come into an electric bike that currently has a nimh, 24v, 20cell battery pack. On the pack as well it says 8000mah. The previuos owner has misplaced the original charger :( The bike has been ...
0
votes
1answer
117 views

Can I use arduino to feed this circuit instead of an external power source?

I am following this tutorial to connect the output from my guitar with arduino. I'm wondering: is it possible not to use the batteries, and to feed the circuit with the 5V output pin provided by ...
-1
votes
2answers
147 views

What does current draw mean for the [closed]

Does this mean that the battery only outputs current equal to the amount of current draw? I always thought that batteries outputted a constant output, but apparently after some research I found this ...
0
votes
3answers
275 views

Boost Converter Problems

I'm having trouble with a boost converter I made: it outputs 1.2V with no load and 2.4 with one. I expect to draw 0.25 Amps MAX with Roughly 0.2 Amps continuous. My battery pack is 2P2S NiMH with the ...
1
vote
1answer
407 views

Reverse current protection for a battery operated circuit

I'm planning a hobby project with the following characteristics 3.3V circuit, battery operated (by regulating standard AAA batteries) Most of the time in "sleep" mode, so I need very small quiescent ...
1
vote
1answer
72 views

How to detect the power source when multiple power sources are available?

I have very little background in electronics, I'm from software background. I'm interested to design a system in which there is an 8-bit micro-controller which should get powered from two different ...
2
votes
1answer
465 views

DC 5V USB to replace AAA-battery source: down converter

I have a portable lithium battery-powered speaker which takes auxiliary sound input from a single AAA-battery powered pocket radio. The speaker includes a USB port for charging source devices: I ...
0
votes
0answers
111 views

Adaptation of LVD (Low Voltage Disconnect) circuit

I'm trying to build a Low Voltage Disconnect circuit with ultra-low power consumption. A quick search on the forum returned a few threads related to LVD, but my question concerns a specific circuit ...
0
votes
1answer
26 views

Mixing battery sizes [closed]

Apologies if this is the wrong Stack. I suspect this is a bit of a lowest-common-denominator question. I've got a cheap little Christmas tree covered in blue festive lights that takes 3 size-C ...
0
votes
2answers
98 views

About battery capacity and regulation

For a portable application, I would be using a single 3.7V 2600mAh li-ion cell. The circuit requires 2.5V to 5V to function with the current requirement being 100mA. So obviously a voltage regulator ...
4
votes
2answers
182 views

How to Check Rechargeable Battery NiMH Status with Microcontroller?

I created a device, based on an Arduino Uno, which runs on 6 rechargeable NiMH batteries. Now I would like to add a check, if the batteries have enough power left, to warn with a signal when the ...
0
votes
1answer
45 views

Any Protection Required for Rechargeable Battery Powered Device?

I created a device which is powered with 6 NiMH AA rechargeable batteries. The device uses between 10-100mA current. It is nothing special about it, there are some foil and electrolyte capacitors from ...
0
votes
1answer
91 views

Understanding Battery rating

I need clarification regarding the rating of the battery shown in the below figure. I know battery ratings are given in Ah(Ampere-hour), but here it is given A/s. The picture is from "Linden's ...
1
vote
4answers
250 views

Convert a device that is powered by a 12V 2 amp ac-to-dc SMPS to a battery powered device

I have looked up my requirements in all possible sources (Google, StackExchange, DiY boards, etc.) but I have not been able to find a clear answer to my problem. What I have is a device that needs ...
0
votes
0answers
97 views

Power micro LED's from 5 Volt USB

simulate this circuit – Schematic created using CircuitLab I'm working with this set of LED's: Link here: 30 Ft Led wire I measured the draw for the entire string at about 170 ...
0
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1answer
83 views

Microcontroller self-shutdown with MAX682

I have read How to implement a soft power switch controllable by microcontroller? and am wondering if something similar would be possible with a MAX682. What I want, is a device that is turned on by ...
0
votes
2answers
176 views

Difference in self discharge rate between Lithium iron phosphate battery vs Lithium Polymer Battery

What is the difference in self discharge rate between lithium iron phosphate battery and lithium polymer battery? I have a remote application in which the self discharge rate matters a lot.
0
votes
2answers
216 views

Capacitor leakage and design for low energy battery powered devices

For the design of a portable battery operated device, I have some power circuitry which requires a DC-DC converter and some other regulators, battery charger IC etc. While in the process of ...