Questions tagged [batteries]

An electric battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy

1
vote
5answers
114 views

When you connect two batteries in series, why doesn't the middle short?

When you connect two batteries in series, why doesn't the middle short? The connection between the positive terminal on one battery and the negative terminal on the other battery has no load, so ...
0
votes
0answers
11 views

How to build protection scheme for Li-ion(lifepo4), backed with supercapacitor for high amp operation?

I am very excited about battery protection circuits (PCBs), which is placed between li-ion batteries, and some "DC-link" bus. They essentially do these functions: Over-charge protection. If voltage ...
1
vote
1answer
57 views

How to generate heat using a battery and a wire

If i connect the positive and the negative terminal of the battery with a wire, the wire will turn red and generate heat.This creates a short circuit.This can damage or explode the battery?Is there ...
3
votes
7answers
1k views

How do batteries connected in parallel give more current than batteries connected in series?

Let's say we have three 1V batteries and we're connecting them to a 1Ω resistor. Connected in series, the voltage is 3V and since the resistance is 1Ω, that means that from Ohm's law, the current ...
0
votes
2answers
58 views

What is the energy density of voltaic piles?

I heard voltaic piles have very small power but long lifetimes so I was wondering what their energy density per unit volume and energy density per unit mass is. If specifying a type of voltaic pile ...
0
votes
3answers
85 views

What power adapter do I need to charge a 7.2V 4000mAh battery that I made?

I made a Ni-CD 7.2V 4000mAh battery. What power adapter do I need to charge it? How many volts and how many amperes should the adapter output? Each battery cell is 1.2 volts. I have a 9V 500mA ...
0
votes
0answers
46 views

Whats the best way to go from 12vdc to ~48vdc if i dont need much current? [on hold]

I have three LTC6803-4 ICs that need more voltage than the batteries they are monitoring(adds up to a max of about 44vdc) but according to the datasheet it draws hardly any current, and I have both a ...
0
votes
0answers
19 views

How to use SPI serial interface with ATSAMD21G18?

Like the title suggests, I have a ATSAMD21G18 microcontroller that I want to interface with a LTC6803-4 chip, but I'm not sure how to set up the SPI bus on the microcontroller, and the datasheet ...
0
votes
0answers
55 views

Kitchen scale claims low battery, but works on power supply [on hold]

I'm trying to help someone repair a kitchen scale, and have run into an interesting problem (at least to me - full disclosure, mechanical engineer who struggled through basic circuits, etc.). On ...
0
votes
1answer
37 views

STM32F437 UART doesn't work at 3.6V~4.2V(lithium battery)

led is on but UART doesn't work when using lithium battery. stm32f437 UART can work at 5V(power supply). ...
0
votes
1answer
71 views

Swollen MacBook battery safety after several weeks of storage [duplicate]

Several weeks ago, I noticed a swollen lithium-ion battery in an older MacBook laptop. Since then, I have not used the device and currently am storing it in a fire safe location. Unfortunately, the ...
1
vote
0answers
51 views

Noise in portable power supply to guitar effects pedals

I am constructing a battery powered power supply for a guitar effects pedal board. There are 5 pedals and I am using a phone charging battery and a boost converter to supply 9v ( centre negative ) ...
0
votes
1answer
44 views

Sense Resistor in Battery Charging Circuit

I have a 3 18650 in parallel Li-ion battery pack and wish to use the LTC4162 as the charger and LTC2944 and the level indicator. I am unsure as to who to wire them to effectively use both. I noticed ...
-4
votes
0answers
89 views

Can SRAM Explode? [closed]

https://www.st.com/resource/en/datasheet/m48z02.pdf Can this SRAM explode if it is connected wrong? It has a button cell battery built in, and also power pins... So if for example these power pins ...
0
votes
1answer
37 views

Voltage regulator STBY & OFF - whats the difference?

I am looking at MAX883 voltage regulator and from the documentation is not very clear whats the difference. It says this about pin OFF: In this mode, the pass transistor, control circuit, ...
1
vote
1answer
40 views

How to solder the 4-pin battery connector back to phone's motherboard?

One wickedly hot day the battery of my old Nexus 4 swelled up. I use that phone as Android development platform, so most of the time it was plugged into the computer for USB debugging. It's been ...
-2
votes
1answer
35 views

Ubuntu Battery Check [closed]

Today morning my laptop wasn't turning on but charging light was on.later some how i able to turn on my laptop.Can be this Battery Problem? Bc i put it on charging for hour. Here is stat.
1
vote
0answers
41 views

Li battery charger reference voltage problem

schematic datasheet I have designed a battery charging circuit for a lithium ion battery.When i connect a battery the charging IC seems to do nothing. Only when i use a multimeter probe to measure ...
0
votes
2answers
36 views

Batteries connection for 3 wheel e-bike

Goodday. I need info on this. If i connect say 3 x 12 volt 28amp batteries in parallel to increase the amp hour that makes it a big 12 volt battery and then connect 2 x 24 volt but lower in amps ...
2
votes
0answers
27 views

24-60V Precharge schematic critique

I'm looking to design a soft-start precharge circuit for starting up circuits with substantial input capacitance (~1.5J @ 24V). The main requirements are: 24-60V compatible Constant current pre-...
0
votes
3answers
59 views

How to monitor the voltage of a bunch of batteries using Arduino?

Ive got about 36 batteries that all stay between 2.8v and 3.6v, and I want to be able to accurately monitor the voltage(and therefor the state of charge) of all of them using an Arduino Nano, the two ...
0
votes
2answers
28 views

Counting pulses in low power device

I have a mechanical water flowmeter with reed switch output and I connect it to my low power, battery powered device to count pulses. The reed switch is connected to my device via a 15 m long cable ...
-3
votes
0answers
44 views

What will be the watt of a battery after a voltage divider [duplicate]

I have a battery of 25 A 24 V and will use a voltage divider to make it 10 V (100 Ω and 140 Ω) and need to know after the reduction of the voltage what will be the current to calculate the watt.
0
votes
2answers
80 views

Raspberry Pi Zero 12V Battery backup to 5V - do I need the resistor?

I found this diagram on the internet which seems to divide the voltage down to 5V and still be able to deliver 1A with the 7805 just like I want. It will use a 12V lead acid battery and a 12V IN ...
0
votes
2answers
47 views

Lithium ion (Li-ion) vs. Lithium thionyl chloride (LTC) battery?

I need some consultation on which battery of the two to use for the GPS trackers I'm designing. My trackers wakeup when there's movement only so they're not on all the time and they have low power ...
0
votes
1answer
47 views

How can I limit the current drawn by a Li-Ion battery pack BMS?

I have a Li-Ion battery pack made with twelve 18650 in a 3S4P configuration, using an off the self Battery Management System (rated for 25A), that I purchased on aliexpress. I tried to charge it using ...
1
vote
1answer
48 views

Reading a low voltage signal from a battery connected to a transformer

So currently I am trying to read the current draw from a battery that is being run through a transformer to generate an arc to light a gas burner. I have a roughly 1 ohm piece of wire that I am ...
1
vote
0answers
40 views

Voltage step up module and if I am using it correctly

I am making a "simple" bluetooth speaker and have followed instructions from a Youtube video on how to assemble the components I have bought. However... I am finding that the rechargeable li-po ...
0
votes
0answers
35 views

Connecting a 12v router to a 12v battery [duplicate]

can I connect a 12v router directly to a 12v battery which normally will be at 13-14v (because most of the time it’ll be charging)? The router is a TP LINK Archer MR200 rated at 12V 1A
1
vote
1answer
72 views

Can anyone help me identify this component from an old rechargeable battery pack? [closed]

I was given an old, maybe 10 years, battery drill, it had seen almost no use, but, unsurprisingly, the battery pack would not charge. I took the pack apart and several of the cells were obviously ...
0
votes
3answers
86 views

How to block reverse current from battery to charger (DC-buck CC/CV module)?

The set-up For a project, I have a set-up where the power to the main load comes from either a AC-DC adapter input (24V) or a battery pack (12V to 16.8V - 4S4P 18650 Li-ion cells). The battery pack ...
1
vote
0answers
28 views

Changing between usb power and battery power using P-Channel MOSFETs and a CMOS Invertor

I am trying to switch between USB power and a single cell lipo using two mosfets. Would the circuit below be ideal or is there a more efficient/reliable way to do this? When the USB is connected the ...
0
votes
1answer
19 views

BMS for 2S Lipos

I have 2 lipo batteries in series, each has a built in protection circuit and these specifications: Voltage: 3.7 Vcc Capacity: 1000 mAh Maximum discharge rate: 2100 mA I need to charge them, but I ...
0
votes
0answers
34 views

12V Lithium Ion Polymer Battery

I am trying to develop a product that requires a 12 V portable rechargeable battery that can output at least 2 A. Since conventional LiPo battery runs only on 3.7 nominal voltage, is it advisable to ...
-1
votes
2answers
53 views

Unknown Battery Connector [closed]

Hi, this is a standard 260mAh 3.7V battery. I've seen this on several listings on eBay, Aliexpress however nobody says what this connector is. In particular I'm looking for the receptacle part of ...
1
vote
1answer
48 views

Bypassing battery cell with transistors

Is it possible to create the schematic below with transistors in any way? As I see it, there is no voltage difference between j1 & j2, so a transistor connected the normal way would not work. ...
1
vote
0answers
68 views

Creating a 3x18650 cell pack in series with 4 in parallel [on hold]

I am going to create a 3S4P pack with some 18650 cells that I got from some lightly used laptop batteries. Using: 8x Samsung ICR18650-22E and 4x LG LGABC21865 After doing some research I found that ...
2
votes
4answers
154 views

How would you wire small computer to run on both batteries and AC power? [closed]

I'm trying to use a motherboard (Mac mini 2018 model) for a project that will require it to be able to run off batteries. The project is essentially building a custom laptop using the Mac mini mobo ...
0
votes
1answer
28 views

Power switch: leaving battery connected at one terminal

Just wondering if there is any real-world practical difference between a power switch that disconnects both terminals of a battery vs a switch that just disconnects one terminal. Are there any ...
1
vote
1answer
17 views

MAX856 Low-Battery Indicator Question

the MAX856 says it has a low-battery indicaitor. My setup has a single 3.7v nominal LiPo pouch and I want it to trigger the low-battery at 3.4V. Datasheet: https://datasheets.maximintegrated.com/en/...
1
vote
0answers
27 views

Where is Olin Lathrop? [migrated]

Oh god I miss him so much but he has not been online for more than half a year oh please tell me he is okay, where is Olin? Who will tell me? Where is the glorious bearded microcontroller man?
1
vote
0answers
62 views

Reducing Current?

Having a problem with my EV a converted Fiat 500. The conversion is made with part from companies that dont exist any more, so it is hard to get information about them. The car have two batterybanks ...
0
votes
1answer
36 views

Custom charger with solar cell

I want to make kind of autonomous power supply for my RPi. So that I am planning to use 12V solar cell and batteries for this project. Also I will use Arduino to controll all of this stuff - to ...
2
votes
1answer
97 views

Accidentally used 3.6 volt battery for my mouse, now it only works with 3.6 volt [closed]

My mouse requires AA 1.5 volt batteries to work. I accidentally used a 3.6 volt Li-SOCl2 battery. Now it works fine with the 3.6 volt battery but doesn't work at all with a 1.5 volt AA battery. I ...
0
votes
0answers
42 views

Current and voltage increasing with duty cycle from buck- converter

I am designing a 2s Li-ion battery charger using a buck converter from a 10W (18V, 0.55A) solar panel. So I understand that the duty cycle controls the ratio of the input power vs output power and ...
1
vote
2answers
53 views

How to calculate remaining battery capacity from charge discharge data?

If a dataset contains data collected over time from a re-chargeable battery and includes information such as voltage, current, average discharge rate and peak discharge rates. how can the remaining ...
0
votes
1answer
95 views

Protected 18650 batteries shut down after I introduce a capacitor to the circuit, why?

I have a 24V audio amplifier that is powered by 8 packs of 6x protected 18650 batteries connected in series to produce 24V, and then all the packs are connected in parallel. The amplifier powers a ...
17
votes
8answers
6k views

Smooth switching between 12 V batteries, with a toggle switch

I have a number of instruments (12 volts, drawing a few hundred milliamperes) that occasionally need to be switched between one of two 12 volt lead acid batteries. The toggle switch is break-before-...
0
votes
0answers
22 views

Voltage drop on system activation

My question is generic in nature about electronics system design. I am trying to put together an RC car which is powered by an AVR Atmega168 chip. It communicates through an HC-12 module and has a ...
0
votes
0answers
10 views

Double A battery & lithium battery charging way

I do have some question regarding the charging input for nimh double A battery & lithium battery. Is it possible for my 7.4volt lithium battery charged with 8.4volt 2Ampere charger? Any idea on ...