Questions tagged [low-battery]

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40 views

18650 voltage slowly rising from an undervoltage

I found some Power bank which haven't been used for quite a lot and connected it to a USB tester to measure the voltage and Amps from the input to the battery controller module. and using a multimeter ...
2
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3answers
116 views

Real thing or just misinterpretation? Rotating batteries to make TV remote work

When TV remote isn't working, I rotate the batteries in the remote in their place and it begins to work. I don't see any kind of deposit between the batteries and the contacts. Rotation of battery ...
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10answers
3k views

Would a 7805 5 V regulator drain a 9 V battery?

Doing some DIY as a hobby, I'm making a small humidity-temperature radio sensor. An ATmega328 is reading from a DHT11 sensor and then transmitting data to a Raspberry Pi by an STX882 radio ...
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1answer
108 views

PNP Transistor Switch for Relay

simulate this circuit – Schematic created using CircuitLab Hi, I have a low battery detection circuit here. When the voltage of the battery goes below 10.5, I have an LED flashing (Uses the ...
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0answers
64 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 ...
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0answers
26 views

Lion Battery Shutdown Mode and Wake on Charge

I'm currently designing a BMS that doesn't rely on a TI bq-series IC for gas gauging, protections, etc. So far, I have analog circuitry handling over and under-voltage cutoff, overcurrent cutoff, ...
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2answers
130 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 ...
2
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2answers
94 views

Monitor coin cell voltage without loading it when power is off

Is there a good way to monitor a CR2032 coin cell's voltage, that does not load it down when other power is off? We are using a CR2032 coin cell for a battery-backed real-time clock. When main power ...
8
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1answer
1k views

Is it normal for a lithium ion battery to read with a very low voltage on a multimeter?

I have a PS Vita and I suspect the battery is dead and needs replacing, as the Vita won't charge at all. But the issue could also be the charge circuit, as when plugging it in to charge the charging ...
2
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0answers
26 views

Deep Discharge of Cells and Batteries

This is a question related to What makes primary batteries leak on very deep discharge? What are the dangers of deep discharging a cell or battery? I've seen a LiPo battery getting puffy most likely ...
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1answer
74 views

MCP73831: VBat Voltage drop with new uncharged batteries

I made a circuit for charging a 40mah lipo battery (381018), my problem appears when a new uncharged battery is connected. The battery measures 0V at the begining, when it's conected the VBAT pin ...
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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 ...
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1answer
79 views

Why doesn't my charge pump work with 1.5v supply?

I have been trying to get the following circuit to work with 1.5V AA battery but it does not work, even though it works fine with a 3.3v supply. I built the multivibrator circuit by discrete ...
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1answer
89 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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3answers
319 views

Battery Life Calculation, Sleeping and Wake modes

I have a circuit that consumes 1.6μΑ during sleep mode and 40mA during awake mode. The awake period lasts for 3 seconds and the circuit is on awake mode every 30 minutes. The circuit is powered by ...
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3answers
245 views

Battery Tester Circuit with 3 LEDS

I'm designing a small system that uses an ATMEGA328P and a LoRa module that runs on 3.3V using a AAA 1.5V battery. The battery is connected to a Boost Converter which steps up the 1.5V to 3.3V to ...
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1answer
222 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 ...
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1answer
52 views

Battery level on battery indicator drops when i connect a load? [closed]

I've got this cheap battery level indicator that has 4 battery level segments, it is connected to a 12V-18AH lead acid battery that I to charge my laptop and my 1W light bulb. I really can't seem to ...
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0answers
44 views

Batteries have spare capacity when unused for minutes after running out? [duplicate]

I tested it with NiZN batteries: After they ran out of power, I measured their voltage. 0.9V. I waited 15 minutes, measured again without charging, and it was at 1.5V. I continued operating a CD ...
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1answer
216 views

current limiting filament bulb, revisited

I'm trying to size a bulb to limit DC booster pack current (harbor freight viking lithium) from overloading the 12V aux port (cigarette lighter) wiring which is fused at 15A. I'm ideally looking to ...
1
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1answer
283 views

Adding Blinking LED to Low Battery Circuit

I'm thinking of designing a PCB based on this low battery indicator circuit: It hooks up to your battery of choice and has a green and red LED, and uses a trimmer pot to adjust at what voltage want ...
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2answers
595 views

Low voltage disconnect with no quiescent current

I'm a noob. Please correct my mistakes. I'm making a circuit where I'd like to protect my Li-ion battery (3.7V, 3500mAh) from discharging too much. The batteries have a protection inbuilt which shuts ...
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1answer
294 views

Q: Can I use the LM3914 voltage indicator IC as a low-voltage cutoff device?

I came across these two circuits, and tried them out successfully: LM3914 Battery Monitor, drives 10 LEDs in a linear relation to the input voltage. NE555 Low-Voltage Cutoff, uses a 555 timer to ...
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0answers
174 views

VBAT transistor switch is unsymmetrical

Hei, In relation to my other topic for the VBAT cutoff circuit, I have now gotten my hardware back to measure the functionality. What I have encountered is that the switch-ON is as planned ~2.3V, ...
1
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2answers
3k views

Can I wake up a sleeping Li ion battery pack without dismantling it?

I have three dead lithium-ion battery packs - two of these and one of these. My multimeter informs me that the voltage of the batteries and they both read 5.6V. I understand that by dropping below ...
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3answers
79 views

Need help with modeling an overloaded battery

I wish to model a battery for a small computer game, a battery which will be subjected to heavy loads and deep discharge. The model doesn't have to be high-fidelity, just a rough approximation will do....
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1answer
118 views

how does a device running on a lithium battery measure the amount of energy left? [closed]

I have a wireless phone and recently i had to replace it's lithium battery. The previous battery was totally dead and would work for like 30 minutes or 1 hour before it showed the "low battery" ...
0
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1answer
112 views

switch load depending on battery voltage

I have the following set up; simulate this circuit – Schematic created using CircuitLab MPPT charge controller: https://www.sparkfun.com/products/12885 Load: Raspberry Pi Zero Battery is: ...
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2answers
509 views

Selecting low power mosfet for battery monitor

I'm trying to implement og test the results discussed in the linked JeeLab post in a low power battery powered device. http://jeelabs.org/2013/05/18/zero-power-measurement-part-2/#comments The post ...
4
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3answers
2k views

Why isn't my battery charging?

I have a YT7B-BS battery in my motorcycle. My motorcycle doesn't start because the battery voltage is only 12.05 Volts. The battery has the following inscriptions: Standard charge: 0.7 A x 5~10 ...
1
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1answer
296 views

MOSFET N-CHANNEL don't switch

I am controlling the voltage of a 3.6V lithium battery with a MCP112-250 (I know it is 3V but I have a diode in series with my battery). And the output is connected to the gate of a N-channel MOSFET, ...
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2answers
278 views

Controlling a LDO with voltage detector

For one of my project I need to shutdown my system when my Li-ion battery reaches 3V.But I want to know if I can use this type of component : http://www.farnell.com/datasheets/11601.pdfhttp://www....
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3answers
841 views

Batteries and running time

If I have a system working at 2.5V-0.3mA powered by two CR123 3.7V-2000mAh.Is my system going to last the same time if I put my batteries in parallel or in series?Because if I want it to last 12hrs a ...
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2answers
1k views

A Lipo battery protection circuit

I would like to create a simple Li-Po protection circuit that will prevent a single-cell from going below 3.7V. My circuit needs to have a low current input detector (pref < 5uA). My attempt at ...
1
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1answer
426 views

Backup battery enable with microcontroller

I'm interested in making a battery backup circuit that is operated by a microcontrollersuch that when the main battery gets below a certain voltage, the system switches to the backup battery. ...
0
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3answers
1k views

Why is voltage level affected by low temperature?

I have designed a circuit that uses this low-battery-indicator: http://www.homemade-circuits.com/2013/05/low-battery-indicator-circuit-using-two.html I use 4xAA Lithium batteries to drive an Arduino ...
0
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1answer
743 views

How to prevent Buzzer circuit to drain battery

This circuit drains my battery way too fast. What can I change to minimize the power consumption? The Buzzer is a electromechanical variant with these specs: Rated Voltage:3V; Operating Voltage:...
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1answer
1k views

Battery cutoff circuit with NE555

For a project, I need a simple battery cutoff circuit for protecting a 9V battery from over-discharging. (by simple, I mean with only a few off the shelf components, and no micro-controllers) Looking ...
5
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3answers
3k views

How do you tell if a Li-ion battery has a protection circuit?

I bought a li-ion battery off of ebay. The listing claims that the battery has a protection circuit, but a week later, the battery didn't cut out or anything. With a multimeter, it is reading 10V when ...
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1answer
2k views

Confused about battery voltage warning circuit with PNP transistor and Zener diode

Below is a circuit where an LED will light on when the battery voltage (Vcc) is below approximately 8.8V. However, I'm confused as to how it works. My understanding is that when the battery voltage is ...
0
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1answer
197 views

How is battery life measured in devices?

I have a thermostat (Siemens REV200) which runs on 2 AA batteries. I've put in 2 brand new (A brand) batteries but the device keeps showing me low battery power signals. How do electronics usually ...
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3answers
406 views

Will this OP AMP work for this application?

I designed the following circuit in CircuitLab. My question isn't about the whole thing, but rather about the TL081 Operation Amplifiers that circuitlab uses as a default(data sheet found here). ...
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3answers
348 views

How do microcontrollers (MSP430G2452/G2553 specifically) behave when the battery runs low?

In the event I decide not to monitor the battery (see below), I'd like to know how microcontrollers behave when battery life is low - specifically the MSP430G2553/2452. Do they reach a point and stop, ...
1
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2answers
160 views

Can you connect in series 2 unequally charged batteries?

So I have 4 batteries. 2 of them are charged (about 70%) and 2 about 10%. I have a flashlight (which uses 2 batteries in series) which I would like to power at small current and voltage because the ...
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3answers
267 views

Voltage Supervisor for low battery

I recently got an electronic engineer to make a design of a circuit for me. He completed everything except for the fact that he never included in the design a way to detect when the battery was ...
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0answers
247 views

Modifiying SparkFun Uh-Oh Batt. Indicator - TL431 Regulator Diode Based

I'm trying to modify a simple SparkFun Uh-Oh Battery Level Indicator - KIT - 11087 https://www.sparkfun.com/products/11087 It can handle a maximum voltage of 12 or so volts, above that I believe it ...
9
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3answers
22k views

If Li-Ion battery is deeply discharged, is it harmful for it to remain in this state unused?

It is well known that Li-Ion batteries should not be deep discharged. But sometimes they do discharge deeply. Is it OK for the device to remain in such state for a long time (and recharge again only ...
2
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2answers
2k views

Are BLE modules capable of working with a CR2032 battery? [duplicate]

I keep reading that the Bluetooth Low Energy modules are capable of working with a CR2032 battery for years, but their consumption is around 20mA and the max discharge of a CR2032 is around 3mA (200uA ...
2
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3answers
7k views

Low battery level circuit - Changing “trigger” level

I am re-creating a simple low-battery level circuit that turns on a low-power LED to indicate that the battery needs to be changed. The circuit is shown below. There are two things I would like to ...
5
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3answers
857 views

Does CKDIV8 save battery life when programmed?

On ATmega328P there is a CKDIV8 fuse bit that when programmed divides clock by 8. I'm wondering if the power consumption is equal on these two setups: micro with 8MHz external crystal and CKDIV8 ...