Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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).

776 questions
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Why do batteries recover after a load is removed?

I carry a small 2-AA flashlight, and a few times, I have accidentally left it on in my holder. Each time it dies completely, so that no light is emitted, but if I turn it back off and wait for a few minutes, the light works weakly again. The…
Daniel
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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, but I came across diverging opinions... Which one…
DryRun
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Can I disable a battery powered device by reversing half of its batteries?

When I have a device that is powered by two batteries, can I disable it by turning one battery around? For illustration, the purpose is to leave batteries in the device for storage, but it does not have an off switch. There are multiple solutions…
Volker Siegel
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Why do batteries in consumer electronics get used unevenly?

When changing the batteries of kids toys, remote controls, etc., I test the batteries and have noticed that they drain differently. One will be dead and the other is still in the green. Why does this happen? Also, at this extreme, why not just have…
user1605665
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3 answers

Lithium Coin Cell CR2032 battery specifications

I am using a CR2032 battery module to operate a BLE 4.1 module. The BLE radio for communication takes around 3.5ma to 5ma of current. But when I look at the datasheet of the battery…
Viral Embedded
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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?
Ryan Detzel
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2 answers

How does this mosquito zapper circuit work?

For the purpose of learning, I have tear down a small mosquito zapper racket. I am now trying to understand how the circuit is working (which goal is to produce high voltage). (yellow = resistor, black = transistor, red = led, gray = diode, blue…
tigrou
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LiPo vs. NiMH for kid's toy

I've been researching here and on google regarding potential battery technologies for a toy that I want to make for my kids. I was hoping to get others' perspectives on this, keeping in mind that this is for a child. I'm trying to look at this from…
Dave
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How to solder wires on Li-ion cell phone batteries?

I am making a obstacle avoiding robot and wanted to power it with mobile phone batteries. But wondering how to solder wires on battery correctly for no inconvenience. p.s. I am a new arduino enthusiast.
geeky me
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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 with have a maximum current rating, the lead acid…
Chien Hao Tan
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6 answers

Can I connect homemade battery packs in parallel?

I'm working on batteries to run an underwater drone and a follow-boat using 3.7 V, 3400 mAh Li-ion cells. I need a voltage of around 18.5 V and around 20 Ah. The thought-up solution was to make several battery-packs of 5s1p with each battery-pack…
Soft_Kayak
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Using DC voltage instead of AC to supply SMPS

Situation: You have a battery pack with voltage of 300V. You have some appliances designed for 250V AC. These appliances have SMPS inside. Claim: Instead of using DC to AC inverter, you can use DC voltage to supply SMPS inside your…
Viliam
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Possible battery solutions for 1000mAh capacity and >10 year life?

I'm looking into the possibility of running a wireless sensor node for up to 10 years on a single battery. I think the average current draw is likely to be around 70uA, with the peak current draw possibly being 20mA(the average takes this into…
Sensors
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My DIY RGB LED panel powered by 9V battery works but certain colors like blue, white, and purple don't work

I am able to power on my LED unit here with a 9V battery. I'm using a recharble lithium 9V as well. I can't figure out why I can't get blue, purple, and white. The only colors I get are red, orange, yellow, and green. The LED panel is normally used…
Destructo
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Unknown component in an electronic dictionary

I'm exploring the inside of my favorite device, a Japanese electronic dictionary. It runs on AAA batteries and has two screens (one for writing and one for viewing), speakers/headphone jack, a USB connector and an SD card slot. There's a peculiar…
Nate Glenn
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