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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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3answers
73 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
56 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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0answers
38 views

external phone parallel battery

I’m trying to find a way to place a 5000 mAh battery outside of the iPhone 5s case, and perhaps altogether removing the internal one if needed. The battery outside is taken from an external battery ...
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1answer
56 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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votes
2answers
39 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
77 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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0answers
34 views

What is the actual proper way to integrate a balancing charger into a multi-series li-ion pack?

What I want to do is build a pack that in order to charge and use it all you have to do is plug in a wall wart (the way commercial products like laptops, phones, E-skateboards, etc. I have scoured ...
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3answers
90 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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votes
1answer
79 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
58 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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votes
1answer
40 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
15 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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0answers
48 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 could not able to get the voltage at its output pins, the circuit ...
0
votes
3answers
109 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
votes
2answers
71 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 ...
1
vote
2answers
122 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 ...
0
votes
3answers
56 views

Will battery last longer with larger capacity but lower efficiency (high V through LDO) or vice versa?

Given a simple circuit of a draw around 28mA (when supplied 3.3v). I'm trying to maximize run time on a battery, but working with what I've got on hand... I have the following batteries: 5000mAh 3S ...
1
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2answers
84 views

Is it safe to connect a small solar panel to a lead acid with only a diode?

Is my setup safe? I'm connecting two 7.2v 100ma solar panels in parallel using two 1N5817 then to a to 6v lead acid battery with a Constant Voltage Charge of 7.3-7.4v for cycle use.I can't use a MPPT ...
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votes
2answers
65 views

Safe assumption for AA and C battery current draw

I have 5 LED candles with built-in timers, but they eat batteries, so I'm hoping to use an AC adapter to power them instead. They are all different with some using AA batteries and others using C ...
-2
votes
1answer
100 views

Replacement of li po battery with li ion battery [duplicate]

Is it possible to replace a battery for headphones? I would like to replace a 052030 li po battery with a Nokia BL-5C Lithium Ion battery. The li po battery is rated at 130 mAh with 3.7v. The Lithium ...
-1
votes
1answer
82 views

Could I replace headphones NIMH battery with Lithium Ion phone battery of the same voltage?

Is it possible to replace a battery for headphones? I would like to replace a 052030 li po battery with a Nokia BL-5C Lithium Ion battery. The li po battery is rated at 130 mAh with 3.7v. The Lithium ...
0
votes
1answer
47 views

Parallel lipo batteries with mcp73831 charger IC

After reading this very informative blog about load sharing while charging batteries, I'm planning on using an MCP73831 in the same configuration as detailed by the blog for use in a project I'm ...
0
votes
1answer
20 views

Connecting a Lithium battery directly to the GSM module

I have a GSM module (M66 from Quectel) and a single cell Lithium battery,Based on Datasheet module operated in the 3.3 ~ 4.6 V and as I know battery deliver 3.7 ~ 4.2 V based on it's sate of charge....
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0answers
59 views

Is this a temp sensor on my battery pack?

I am trying to modify a battery pack for a Ridgid nailgun to use replaceable 18650 Li-ion batteries. The original pack looks like this: I've printed an adapter which holds 5 cells and wires to the ...
0
votes
1answer
44 views

XBee power supply design using a Li-Po 3.7V battery

I'm currently designing the power supply for a device which uses XBee PRO S2C as a medium of communication. We are using a Lipo battery 3.7V 3500 mAh battery and TP4056 based battery charger. The ...
0
votes
1answer
16 views

Possibility of series connected LIPO batteries for running stepper motor

I have project where I am using a motor driver DM860A2 to run NEMA 34 85 kg-cm stepper motor. Currently I have used a transformer to supply 48V AC during testing. I have with me four 2200 mah 11.1V ...
1
vote
2answers
45 views

How to calculate the required battery capacity for audio system

I'm converting audio speaker to run on batteries. the speaker is Stagg SMS 8p - RMS 90W, peak power consumption 200W which is consistent with 1A fuse for 220V. Say I go with 12V battery - peak ...
0
votes
1answer
52 views

Oscilloscope differential measurement for battery powered circuit using single probe

I want to measure the voltage across a resistor in my circuit. The circuit is battery powered. I don't want to use the two probe method and calculate A-B to get the results. Can I use one probe to ...
0
votes
1answer
28 views

How to calculate 18650 battery use time?

I am currently powering my mini fan using a normal power bank (the one used for smartphone) which is 5V, 2A output and can last for around 6-7 hours. If I power my fan using two 18650 3.7V 2300mAh (...
2
votes
1answer
55 views

Battery to AC conversion voltage question

I am converting a device that uses 2 [C] size batteries (1.5V) to use a transformer in an AC outlet. I understand that the transformer rating should output 3 volts. However.... I only found a 3.2 ...
0
votes
1answer
69 views

ON/OFF push button circuit with battery under voltage protection

I have put together the push button circuit explained in TI's SCEA048B application report with an under voltage protection using TI's LMS33460 chip. I ended up with the circuit attached. The idea is ...
0
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1answer
123 views

Not enough power going through IRLZ44, activated by Arduino

I've a 9v battery and I'm trying to get 9v through my IRLZ44, to power an solenoid. It's a seperate system from my arduino who's sending a 5v signal to the IRLZ44 in order to activate it. For some ...
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0answers
13 views

Where can I get informations about smartphones battery datasheet?

I'm hardly trying to find the datasheets and I still got nothing :(, what I was try to find is like Asus battery for Zenfone 4 Model: C11P1404 datasheet. Please for your kindness tell me where can I ...
2
votes
1answer
27 views

Hooking up a battery to a BLE beacon

I am looking to add a battery to this BLE beacon with as few parts as possible. In their product's datasheet they include a section on an example schematic for adding a battery (included below). My ...
1
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2answers
120 views

Battery reads 5V but can't power a 5V sensor?

I have a circuit set up similar to that shown bellow which allows readings to be taken from an infrared sensor (MLX90614) using an Adafruit Feather HUZZAH ESP8266. This works fine when the battery ...
0
votes
1answer
44 views

How can software give an accurate estimation of remaining usage time for a worn battery?

I understand that the system can read the current voltage and determine battery remaining percentage from that. Say, if a Li-ion battery in a mobile phone is at 4.3V, it's likely the battery is full. ...
0
votes
1answer
37 views

Control the output current of battery

I used DC-DC to get 3.3V supply from my battery with 3.6V capacity. I used large battery (connected number of cells in parallel) for long term operation of device (81Ah). So my questions are: -> I ...
1
vote
5answers
78 views

Using battery to operate a DC load

FOLKS, am a learner. This is the problem am trying to get around. what would happen if I use a 200amp 12V battery to run a dc standing fan of say 2amp power draw or a piano of same rating or any ...
0
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3answers
68 views

Can 2 9v batteries heat an electric range heating element

For an experiment I am trying to power the heating element in the link attached. http://www.appliancepartspros.com/frigidaire-range-surface-element-316442300-ap4356466.html My goal is to power it ...
2
votes
1answer
50 views

Speedcontrol for a 14.4V DC 20A motor

So, for a small home-made engineering project I have cannibalized a 14.4 V DC 20 A motor from a Bosch battery powered screwdriver/powerdrill to spin a flywheel. I'm still using the trigger (...
0
votes
1answer
72 views

0-1А adjustable current source IC for dimming battery powered LED [closed]

I'd like to build an adjustable current source for battery-powered LED lamp to dim it so I can adjust its brightness for reading while using it. It is originally powered by 4V 0.75А PSU but consumes ...
0
votes
0answers
44 views

Does mixing and matching battery capacities result in a bottleneck when wired in series?

I want to make a 12V battery pack to run an Nvidia Jetson TK1 for an afternoon. I am new to using batteries and was wondering - will mixing smaller capacity lithium ion batteries with larger capacity ...
1
vote
1answer
41 views

+ and - 12 V power supply with 12v Batteries, How to make a ground rail with both batteries

I'm new to electronics. I want to make a battery supply to power an OPT301M {photodiode with integrated op amp} and an ADTL082 dual {op amp IC} in order to attempt to reduce noise in the circuit. I ...
0
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0answers
35 views

How to turn off MQ-135 to save power

Newbie trying my hand at building a cheap air quality sensor running on battery using NodeMCU dev board. Been stuck for 3 months trying to figure out how to save power by turning off the gas sensor ...
0
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1answer
119 views

Higher brightness LED with bigger resistor to save battery life

I need to run three LEDs for indoor indication purposes and want them to be around 500 - 1000 MCD. I will run them off batteries and I'm wondering if there is anything I can do to increase battery ...
0
votes
1answer
89 views

Battery power to DC mains power [closed]

First time posting here :) Hope someone can help. I have a wireless Yale home alarm system and the external siren is chewing through batteries in no time and is expensive to keep replacing them. I ...
0
votes
1answer
67 views

What DC motor controller will work for a small toy train? [closed]

I'm thinking about modifying a battery-powered toy train to use a higher voltage battery so the toy can go faster. Like this: https://youtu.be/qK-IVIllOBY?t=30 The 9V battery has a nice form factor ...
0
votes
1answer
24 views

lithium ion battery in series discharging question

Trying to connect 4 12V 5Ah lithium ion batteries in series to make 48V 5Ah source. If my circuit is running on lower amps than 5, lets say 1A. Is the batteries going to be fully discharge in 5 ...
0
votes
1answer
33 views

Latching control via active-high battery supply / regulator shutdown pin?

I'm looking to supply an MCU (3.3 V) from battery via voltage regulator: a pushbutton should enable the supply, the MCU then should keep the supply enabled until it wants to shut itself down. But the ...
1
vote
1answer
73 views

Precise low power millisecond timer

Any suggestions on a low-power programmable timer that does something like the following (to wake up a microcontroller)?: Shortest delay I need is about 10ms. Highest delay I would like is a few ...