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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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DW01x vs AP9211

I plan to use DW01A + FS8205A for LiPo (or LiIon) battery protection. But when I searching alternatives I found AP9211 (internal Dual N-Channel Enhancement Mode Power MOSFET). Is anyone works both of ...
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50 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
52 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
44 views

Battery Power Source for Wireless Router & Modem? [on hold]

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
81 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
71 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 ...
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1answer
47 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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40 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 ...
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1answer
25 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 ...
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1answer
32 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 ...
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1answer
106 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....
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2answers
72 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 ...
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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 ...
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2answers
53 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 ...
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1answer
68 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 ...
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1answer
46 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 ...
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1answer
86 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 ...
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1answer
45 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 ...
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1answer
67 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 ...
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2answers
115 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-...
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1answer
39 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 ...
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3answers
78 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: ...
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2answers
104 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 ...
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2answers
69 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 ...
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1answer
124 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 ...
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1answer
60 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.
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1answer
86 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 ...
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0answers
58 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 ,...
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3answers
299 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 (...
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1answer
49 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 ...
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2answers
120 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 ...
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2answers
51 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 ...
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2answers
67 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 ...
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1answer
43 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 ...
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0answers
62 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 ...
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3answers
203 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 ...
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3answers
106 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 ...
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0answers
78 views

Uninterrupted power supply with auto shutdown lead Acid Battery

Bellow circuit is an uninterrupted power supply(4.7 Vout after regulator) with auto shutdown when the battery is low. I am using a 6-volt lead acid battery with 9v charger. I am looking for an Idea ...
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1answer
139 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 ...
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2answers
52 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 ...
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2answers
92 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 ...
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3answers
112 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 ...
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1answer
114 views

Which DC-DC converter for a uController

I want to power a uC project (uC is a STM32, supposed to be powered with 3.3V) over a LiPo battery. Since LiPo's output ranges from 4.2 volts to 3.7 volts, I feel unsure whether to use a step-down or ...
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votes
1answer
75 views

9v battery voltage goes down very low when connected, but shoots back up when it is disconnected?

Whenever I leave a 9v battery connected to my circuit (simple circuit connected to a motion sensor) It goes down to about 3.3v, but when I disconnect it again, it will slowly go back up to about 8v. ...
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1answer
383 views

Excessive voltage drop from LiPo battery

I am using a 750mAh 25C 3.7v LiPo battery for a custom electronics project which currently draws ~1.5 amps, far below the rated operating current of (0.75 * 25 = ) 18.75 amps. However, at the battery ...
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0answers
19 views

Dedicated li-ion step up drivers

I have a design which will include the optional use case of boosting up to 7V from a li-ion battery. I can't seem to find any drivers dedicated to li-ion for this? There seem to be a few buck boost ...
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1answer
336 views

Lithium ion battery protection IC not able to drive MOSFET

I have integrated the TP4056 charger design into my PCB. The problem is that when I connect the battery at the battery terminals, I am not able to get the voltage at its output pin. The circuit can be ...
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3answers
1k views

Running 12V PC Fan with 9V Battery

i got an old PC fan which according to its label runs at 12V drawing 0.14Amps. I would like to run this with a 9V Battery so that it doesnt go too fast. Does this make sense? How long would the fan ...
2
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2answers
82 views

Solar powered water pump - need some advice

I am completely new to elecrical engineering, but I want to give it a shot and am really interested in learning more details about how all of it works. I've had an advanced physics course in high ...
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2answers
132 views

Why is it recommended to not use a device while charging? How does it harm the battery or the device?

I was planning on getting the new VR headset from Oculus, dubbed Oculus GO. The battery life of that thing is roughly 3 hours max. So, during long VR sessions, powering the headset via a power bank ...