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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2answers
58 views

Boat Auxiliary battery - this simple ok?

I have feared running out of battery voltage to start the boat engine after running the electronics with the engine off. Would something as simple as this figure work? Obviously both are 12V. Main is ...
0
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1answer
40 views

I have a solar powered keyboard [closed]

I'm no engineer and am no electronics type person at all. I friend suggested I post my question here. I have a solar powered keyboard that uses an ML2032 3v lithium battery. I ordered a new one and ...
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0answers
6 views

Question about Solar Panel and Lithium charging board

I have a 6V 4.5W solar panel which I would like to use to charge my Lithium-Ion batteries. The battery chargin board accepts 4.5-5.5V. Would it still be safe to use it with 6V? If not, should I just ...
0
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1answer
49 views

3.3V Voltage Regulator for LiPol battery [closed]

I'm looking for a low drop voltage regulator to use in a 600mA – 1000mA (peak) 3.3v system that can be powered either through a singe-cell LiPol battery or USB (so a max drop of ~0.4V). So far the ...
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0answers
28 views

Powering LCD driver board with li-ion battery pack causes screen to go on and off

I have PCB8000099-V.6 HDMI to LCD board. I am trying to power it using 5V 2A USB li-ion battery pack. When I do so the screen repeatedly goes on and off. What would cause that to happen? I am using ...
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2answers
34 views

Picking battery for power amplifier

I have bunch of TDA2003 (class AB) amp ICs and I would like to make some amplifiers with them. One would be stationary bridged 20w version and one portable version. However I'am a beginner and I never ...
0
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1answer
64 views

Potential safety hazard? [closed]

Suppose one uses a poor 18650 (low quality and without a datasheet) to charge a phone and the phone tries to draw 3A-4A (2A @5V) from it. Would this be hazardous even with a protection circuit built ...
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2answers
156 views

How come 2 MOSFET chips are needed in protection circuits?

Like those here, the protection boards have at least 2 MOSFET chip (AO8814). Does anyone know why so many (4 fets) are needed?
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1answer
40 views

Implementing protection circuitry for a single cell [closed]

I'm hoping to embed a protection circuit for a single 18650 in my device's circuit. No over-charge protection is needed since it won't allow charging - so only protection against over-discharge, ...
0
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0answers
32 views

How to make a Lithium-Ion battery sub-zero proof

I'm planning to use 2 Lithium-Ion batteries in parallel to power my arduino via a step up converter. The batteries get charged using 5W a solar panel during the day. The problem iy, temperatures can ...
0
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2answers
118 views

Can I use a transistor to switch to battery backup power when main power goes out?

I am putting together a circuitry, and I want the circuit to continue running even after main power goes out. So I was thinking about this idea of using a PNP transistor and a one-way diode to ...
0
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1answer
22 views

Run LED strip from battery

I'm making some lighting for my safe I have one metre of LED strip it runs on 12volts at 1000mA and A magnetic read switch how can I run them off a battery ? I tried a 9volt battery but it got ...
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1answer
32 views

Mounting battery terminal contacts in an aluminium case

I'm trying to mount AA terminal contacts in an anodised aluminium case. Given that the aluminium is anodised, does that mean it's not conductive and the contacts could directly make contact with it? ...
2
votes
2answers
195 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
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2answers
106 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 ...
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1answer
116 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
100 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
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1answer
108 views

Can I get 12V out of a 3.6V battery

I know that is probably an extremely stupid question but Can I get 12V out of a 3.6V battery? I have a faulty LED hula hoop (which currently has rows of LED's, some broken!) and I want to insert a ...
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2answers
250 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
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1answer
69 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
70 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 ...
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4answers
97 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
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1answer
90 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. ...
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1answer
174 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
51 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 ...
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1answer
81 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 ...
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2answers
65 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 ...
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1answer
34 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
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1answer
63 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
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1answer
79 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
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2answers
83 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
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2answers
151 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 ...
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1answer
102 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. ...
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1answer
63 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
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1answer
83 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 ...
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0answers
74 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
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1answer
77 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 ...
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1answer
61 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
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1answer
55 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
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2answers
118 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, ...
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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
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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?
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1answer
40 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
966 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
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0answers
102 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. ...
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1answer
216 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 ...
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1answer
134 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 ...
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votes
1answer
118 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 ...
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2answers
160 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 ...
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3answers
297 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 ...