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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).

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2answers
56 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 ...
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1answer
102 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 ...
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1answer
178 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 ...
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0answers
69 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 ...
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0answers
59 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 ...
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0answers
68 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 ...
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0answers
21 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 ...
2
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0answers
67 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
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2answers
562 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
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2answers
55 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 ...
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0answers
116 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 ...
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1answer
174 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 ...
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1answer
251 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. ...
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2answers
135 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 ...
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2answers
100 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
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1answer
120 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 ...
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0answers
65 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 ...
1
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1answer
196 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
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1answer
254 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
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1answer
112 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
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2answers
366 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
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2answers
2k 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
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2answers
93 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
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1answer
80 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
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1answer
114 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
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1answer
208 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
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1answer
83 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
108 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
313 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
123 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
207 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: ...
3
votes
2answers
162 views

Boost converter with battery issues

I have a battery application. With an 11.1 V battery input, I need to maintain a 12 V, 2 A output as the battery discharges. I bought a 1500 mAh, 11.1 V LiPo battery pack with a 35 C rating and I ...
1
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2answers
171 views

DC Motor PWM Circuit Implementation

I'm a little new to this, so bear with me: I am working on a hobby-related project that involves the operation of two DC motors in parallel, powered by a NiMH battery. (Crappy circuit diagram ...
-5
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1answer
283 views

Battery capacity calculation/method [closed]

While calculating battery power capacity requirement for a circuit consisting of multiple loads having different power consumption, how should one proceed to avoid any error? How it is done in ...
-2
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1answer
90 views

Battery Run-time/capacity calculation

Problem is to find the difference in run-time between: a. Using 12V 10Ah battery vs 24V 5Ah battery. PS: Load is rated at 12VDC and 24V to 12V step-down conversion is available.
0
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1answer
103 views

Convert something that runs off two D cell batteries to instead run off a car battery

I do not know much, but I have a portable shower (http://help.venditiogroup.com/support/solutions/articles/6000178636-zenvida-portable-tankless-water-heater-outdoor-shower-260-pcwh01) that I would ...
2
votes
0answers
98 views

What is the reason for high frequency noise when amplifier is powered with battery?

Hi I made a small headphone amp and powered it using lipo battery.voltage is stepped up to 5v.everything is working with direct supply (ie., while charging battery)but as soon as I unplug the charger ,...
0
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3answers
1k views

How do I get 5V 10A output from a 3.7V li-ion battery for 64x16 led matrix display module?

Please I am new to electronics and new here. I'm doing a project which involves the use of a 18650 li-ion battery (or two as may be the case) to power a 64x16 led matrix display module which (...
0
votes
1answer
70 views

What is the best battery configuration for a solar powered electric fence setup?

I have two solar panels: SunWize SW-85P; 85W max power, 5.1A, 16.7V. I have a charge controller: SOLAR BOOST 2000E. I have four 12V batteries: two Interstate SRM-24 (couple years old), two CarQuest ...
1
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2answers
323 views

make LED 12v light fixtures

I would like to remove the n27 sockets from household light fixtures and replace them with LED lights used in the automotive industry. I would like to put a reasonable amount of LEDs in the fixture to ...
2
votes
2answers
115 views

How to size a battery for a starter motor?

I am trying to size a battery for a starter motor for a 120cc 2-stroke engine. The starter is listed as 12V/250W (so 20A draw). The engine manufacturer offers a 3000mAh NIMH battery (so like ~30A max ...
0
votes
2answers
105 views

Hovercraft not moving at all [closed]

I'm a beginner in electronics. I tried making a hovercraft that looks like this: The bottom looks like this: And the battery used is this: I have used a 9v motor, a 9v battery and a dual blade ...
1
vote
1answer
44 views

Calculate battery duration [duplicate]

Maybe this is a trivial question, but I am struggling with it for a while. I have an alkaline AA battery which is consuming 80mA for 8 seconds each 30 minutes. I need to calculate how many days it ...
0
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0answers
106 views

battery backup switching

I am working on an appliance project in which I have been tasked with the design of the power supply. The project specifications hold that from a 230v 50Hz wall supply two voltage rails of 5v (for ...
0
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3answers
218 views

Is everything OK with this circuit?

Coming from this question, I decided to have some changes. So my case is I have an LED with this description: Dimensions (diameter x height): 20 x 8 mm Operating voltage: 3,4-3,6 V Rated current: 700 ...
0
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3answers
192 views

Can I replace a battery with a source of the same voltage but different capacity (mAh)?

I have a device that has a bad battery and I am trying to find a suitable replacement. There are no replacement batteries for the device so I am trying to put something together myself. The original ...
-1
votes
1answer
178 views

Lead acid battery charging current dosent become zero

Here I am charging a 6V 4.5Ah lead acid battery by using a 8V-10V LM317 input supply for the circuit. I'm using the BD139 transistor to cut off and a 6.8V zener diode. As the battery voltage reaches ...
0
votes
2answers
75 views

SLA battery constantly being charged and used

I have a 12V 7Ah SLA battery with a smart battery charger for SLA batteries with the maximal output of 0.8A. I would like to use the battery to charge an Arduino board with few other things (at most ...
0
votes
2answers
121 views

How can I power mobile devices from my 36v or 48v battery safely? [closed]

I want to buy a rear rack battery for my bike, but not for powering the bike. Instead, I want to power other things, such as an action camera+gimbal, a mobile phone charger, grip warmers, lights etc ...
1
vote
3answers
113 views

How to find out which end of a dead battery is the anode, and its voltage [closed]

The battery pack for an old rc car I played with as a kid, has died. Salt crystals everywhere, smells like vinegar. The pack consists of 8 batteries of AA-size connected in series. The red markers ...