Questions tagged [low-battery]
The low-battery tag has no usage guidance.
98
questions
0
votes
0
answers
29
views
Why would a battery pack read as a lower voltage before being disconnected from device, then read as a higher voltage after [duplicate]
I'm working on a device that uses a proximity sensor to count the number of times something passes through its field of view at a certain distance. It is connected to an Arduino Nano and a battery ...
- 319
0
votes
1
answer
63
views
Electric guitar with active electronics and a DIY battery gauge
There is a primitive DIY battery charge monitor which blinks a LED after input voltage drops lower a certain level. Let's call it battery gauge. Also, there is an electric guitar with active ...
- 101
0
votes
1
answer
24
views
RTC UPS power cycle on low battery
My RTC UPS switches on and off the whole time when the battery is low.
I think it could be with the voltage monitor circuit as with the led indicator on the ups it shows the ups's battery voltage is ...
- 1
1
vote
1
answer
55
views
Are there any substitutions for depletion PMOS transistors?
I am currently building a low-voltage cut-off circuit. When the battery is under 10 V, the microcontroller should pull the battery power to ground which will blow the fuse with high current and cut ...
- 35
-1
votes
2
answers
113
views
When is it time to change out batteries in multimeters?
On my multimeter, the D.C. voltage readings get inaccurate over time due to battery discharge.
How can I tell when to change out the batteries?
By consulting the manuals, I found what is displayed ...
- 209
1
vote
1
answer
211
views
Ultra-low power low battery disconnect circuit
I am trying to design a circuit to replicate the behavior of the LTC4071 battery charger/protector IC (see datasheet here). In particular I want to replicate the low battery disconnect function which ...
- 121
3
votes
1
answer
114
views
Single-cell lithium battery powered comparator circuit with hysteresis
I recently was reviewing a circuit I made and began to question its feasibility. The circuit cuts off a battery's connection to a load after the voltage has fallen below a certain threshold.
To ...
- 1,223
1
vote
1
answer
59
views
Trinket M0 - Using USB serial out when running on battery
I am using a Trinket M0 for navigation lights on an electric R/C plane. I thought it would be useful to also use it to monitor my LiPo voltage so I know if it is safe for another flight. For debugging,...
- 135
0
votes
2
answers
861
views
Voltage of 3 V batteries [closed]
I ordered 3 V CR2 batteries. Actually they are 2.92 V and 2.93 V.
Should I consider them faulty, or is this difference from the nominal voltage acceptable?
- 189
0
votes
2
answers
397
views
Low-voltage shut-down compatible with deep sleep in a battery-operated ESP32
I'm designing a battery-operated device driven by an S2 mini board, which is based on an ESP32-S2 microcontroller. In order to save battery the board wakes up every 15 mn, does its thing, and then ...
- 175
1
vote
0
answers
83
views
What would prevent a new AGM battery from fully charging?
What can prevent a new out-of-the-box AGM battery from fully charging, given that neither age nor sulphation are factors?
Specifically, one of the six cells in my brand new Parts Unlimited battery is ...
- 139
1
vote
1
answer
153
views
Cheapest way to detect low voltage of a battery
I have 29V battery which drops to 24V at about 30% capacity.
I want to detect when the battery goes lower than 24V and generate a 12V signal. (I have 12V auxiliary supply for lights etc)
Since I'm ...
- 1,120
1
vote
1
answer
384
views
Dual cell protection using DW01
I am using GS7001B-84 dual cell charger to charge battery. Now I want to protect these two cells. I have DW01 battery protection IC and AP2302B N channel mosfet. How can I protect battery using these ...
- 47
1
vote
0
answers
156
views
Relay Buzzer Circuit
I'm trying to set up a circuit to protect a battery in a battery box, using some parts I had lying around. Its job is to open the primary relay (load/charging) and sound a buzzer when the supply drops ...
- 11
0
votes
3
answers
978
views
Can we use Zener diode as battery low voltage cut off?
Suppose we have 150 watt and 300 watts portable photovoltaic system with 13.5V battery (50Ah) and we want the low voltage cut off point to be set at 10V.
Can we achieve this simply by using zener ...
- 15
0
votes
0
answers
430
views
Wake up MCU with radio signal using a battery
Currently I have a project that runs with the chip from Arduino (Atmega328p).
This is what it does:
It wakes up.
Powers the NRF24L01 module. And it configures it to only send one packet
...
- 557
0
votes
1
answer
83
views
Under what conditions does a p-FET gate have to be at a higher voltage (or more negative) than its source?
Is there a general rule for p-FET's that explains when Vg can can be higher (or more negative) than Vs? I had posted a while back and a helpful person explained I needed to keep Vgs higher than Vds, ...
- 301
0
votes
1
answer
756
views
12 V, 7 Ah SLA battery reads 0 (zero) volts
I have a new 12 V, 7 Ah battery which reads 0 (zero) vokts. Let me explain the situation. I have a 800W UPS (for pc) whose battery wasn't giving enough backup. So I decided to replace the battery. I ...
- 1
0
votes
1
answer
183
views
Battery Charger Cut off
I need to confirm that this circuit will protect battery against over charging or not.
https://bestengineeringprojects.com/12v-7ah-smart-battery-charger-with-pcb-diagram/
Which is better circuit for ...
- 1
3
votes
2
answers
332
views
Why does this lithium battery have such a flat discharge curve?
I'm trying to understand some apparently anomalous observations of the discharge profile of a 1S lithium battery. I'm using this battery to run a Raspberry Pi Zero W, back-powering the Pi via the +5V ...
- 133
1
vote
1
answer
70
views
How to estimate Li-ion battery health for an unused smartphone? [closed]
I am considering purchasing a new smartphone that is several years old and could use a little electrical engineering help from the EE geniuses here.
I've performed quite a bit of research, and found ...
0
votes
1
answer
52
views
Questions about Li-Ion batteries
I am working on integrating single 4.2V Lithium battery(400mAh capacity), charger IC, and battery fuel gauge for an embedded project.
I have watched several TI training videos about battery management,...
- 261
1
vote
1
answer
500
views
Li-ion vs Li-Po batteries cut-off protection
I am confused with the differences between Li-ion batteries (like 18650) and Li-Po (the flat ones).
I know that basically they are both lithium ion, but when I want to buy I see that LiPos have always ...
- 11
1
vote
3
answers
2k
views
Running a 12v fridge and protecting the battery from low voltage
I want to run a 12V (65W) fridge from a battery circuit on a boat. However, I want to protect the battery from being drained and potentially damaged by the fridge if the voltage drops too low so I ...
- 119
1
vote
5
answers
188
views
One battery slot kills its sitting battery
My kid has a battery-operated toy, it runs on three AAA batteries, connected in serial. Once, the toy suddenly stopped working, but all batteries were good. I decided to disassemble the toy and look ...
- 29
0
votes
1
answer
119
views
Abracon AB1805 RTC IC - additional resistance on VBAT pin?
I intend to use Abracon AB1805 RTC in designed device, powered by a CR2032 battery. IC datasheet contains a note: * Total battery series impedance = 1.5k ohms, which may require an external resistor
...
0
votes
2
answers
1k
views
What should a 12v solar battery read while in use?
I have a 12v solar system with 2 12v batteries (One marine, other a car battery).
My inverter has a minimum voltage input of 11.0v and peak of 15.0v, but when I'm running it under load, I get a ...
- 55
1
vote
2
answers
2k
views
How does the TP4056 overdischarge protection work?
I want to buy this integrated circuit (IC) to charge li-po battery. TP4056 Type-C 1S 3.7V
It looks nice for charging but I am afraid of the overdischarge protection of this IC because in the ...
- 1,049
1
vote
1
answer
618
views
How to use Voltage Supervisor and MOSFET to switch off ESP32 supply?
I am planning a solar project using following components:
Solar cells
18650 battery
TP4056
MCP1700-3302E
TC54VN2902EZB Voltage Supervisor
IRLZ44N
and an ESP32
I have only seen a block diagram for ...
0
votes
0
answers
33
views
Charger says 5-cell li-ion battery at 17.7 volt OCV dead or deeply discharged, what could the cause be?
I have a lawnmower with two lithium-ion batteries. I charged them after sitting during the winter period. One battery charged happily to 19.15 volt open circuit voltage (OCV), whereas the other had ...
- 1,563
0
votes
2
answers
401
views
What does it mean when a battery still has high voltage but doesn't deliver current?
All the dead batteries I tested had very small voltage and no current under load except one strange battery that had about 2 volts but no current. What causes this different type of dead battery?
0
votes
1
answer
339
views
How to use LBO on Powerboost 1000C as input for Arduino
I am using a project which uses an Arduino Uno and a powerboost 1000C. in the manual it says,
LBO - not a leveraged buy out! this is the Low Battery Output. By default it is pulled high to BAT but ...
- 248
1
vote
2
answers
748
views
Should I add an undervoltage protection for lithium battery-powered projects?
I am designing a board with a microcontroller (an ESP32) that will be in deep sleep most of the time. The board will run on a 1-cell lithium battery (not sure if I will use a Li-poly or a Li-ion).
...
- 233
0
votes
2
answers
2k
views
Reason why an inverter will drop the battery voltage from 24 to 10V after turned on and then immeadetly shut down?
I reacently modified an off-grid solar system, nothing fancy just included an automatic "turn on" switch for the Victron Phoenix 24/220 1200VA inverter.
Then I connected the loads (2 computers, ...
0
votes
0
answers
91
views
Is the SkyRC B6 Nano charger suitable for charging single 18650's from 2.4v-2.6v
I have salvaged six 18650's from a laptop we've owned for years. Battery voltage: four of them are ~2.63v, two are ~2.46v
I have a SkyRC B6 Nano charger (https://www.skyrc.com/Charger/B6nano). I've ...
- 101
0
votes
1
answer
63
views
How to prevent circuit from shutting down when motor drain too much power
I have a device which has motor and circuits with PLC. This device is connected to a 12v battery which is powering the PLC and motor. Everything is working fine but when the motor's load is heavy, it ...
- 11
1
vote
1
answer
1k
views
6v battery low voltage cut-off circuit
I have a circuit that draw 150 ma and i use 6V/4Ah dry cell to supply. Voltage regulator of this circuit needs minimum 8V so I use boost converter to draw the battery voltage to 8 volts.This converter ...
- 109
2
votes
3
answers
553
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 ...
- 23
9
votes
10
answers
5k
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 ...
- 323
0
votes
1
answer
442
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 ...
- 106
3
votes
0
answers
102
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
votes
2
answers
872
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 ...
- 441
8
votes
1
answer
5k
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 ...
- 183
2
votes
2
answers
81
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 ...
- 358
0
votes
1
answer
191
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 ...
- 11
1
vote
1
answer
75
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 ...
- 173
0
votes
1
answer
178
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 ...
- 215
-1
votes
1
answer
382
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. ...
1
vote
3
answers
2k
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 ...
- 103
0
votes
3
answers
658
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 ...
- 537