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Questions tagged [batteries]

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

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2
votes
4answers
162 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
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1answer
30 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
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1answer
21 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
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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
40 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
98 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
44 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
65 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
23 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 ...
3
votes
3answers
136 views

Why does there flows no current through the common part of the circuit?

I saw there was a post asking the same question here but I still don't understand it. I am reading the book Code: The hidden language of computer hardware and software and the book shows the ...
0
votes
1answer
69 views

Battery charging over USB-C (using USB-PD?)

I'm designing my first PCB, a wireless Keypad/Macropad with a battery. I'm probably going to be using a 2Ah Li-Ion battery because there will be a lot of LEDs on it and I just want it to last longer ...
3
votes
2answers
816 views

Replacing NiMH with Li ion [duplicate]

I have a rechargeable vacuum cleaner with NiMH batteries, 1800mAh and 14.4 volts, 12 cells. The charger is 18v 200mA. The batteries have now died. Can I replace the batteries with 4 cell Li-ion in ...
0
votes
2answers
51 views

Why would a BMS (or other circuit) have reduced voltage after a short?

I have this 9Ah 42v battery pack protected by a BMS wrapped in a shrink which I would rather not disassemble (so I don't currently have access to BMS' circuit). It has two wires for charging, and two ...
0
votes
3answers
31 views

Ideal Battery in Circuit

Does Kirchoff's voltage law hold when we connect a single battery to a circuit that has no other components. If it does hold, kindly let me know how. If it doesn't, how do we reconcile with that?
0
votes
4answers
85 views

No potential difference between the negative terminal of battery A and positive terminal of battery B?

I know that if you have two batteries, battery A and battery B, and connect the negative terminal of battery A to the positive terminal of battery B, there is no potential difference. If you consider ...
0
votes
1answer
63 views

Smartphone battery: safe for (further) use? [closed]

I disassembled my smartphone, which required removing the (non-removable) battery. The battery was glued with double-sided adhesive tape to some housing on the board. Further, there was some 'metallic'...
0
votes
2answers
60 views

Using a 12V battery while simultaneously charging via Heavy Duty battey charger

Very similar to a question asked and answered but using solar panels.. BUT this time I'm asking, Can I use my 135Ah deep cycle battery to power a 2000W inverter and at the same time charge my battery ...
0
votes
1answer
23 views

MB85RC256V for data logger sensor project?

Please. I need somebody can tell me if I can replace a SD card module of arduino to use instead a MB85RC256V fram module 32KB. I want to save power of 3.7 battery, but I am not sure if I can use a ...
1
vote
2answers
76 views

Circuit to tell Microcontroller when Voltage is Low

I would like to trip an input, similar to a button input to an microcontroller if the input voltage to the circuit/microcontroller is below a certain threshold. I have transistors and some zener ...
0
votes
0answers
58 views

BQ2002, LM317 NiMH charging circuit. How to control the current output?

I have designed a charging circuit utilising the BQ2002 and LM317 for 2x 1.2V NiMH batteries, and it is to be charged using a 5V USB input, I need the output current to be between 550 mA and 1A. I ...
1
vote
1answer
66 views

Turn on a device if voltage drops below a configurable level?

Consider a Li-Po battery that has to be protected from damage by going below 3V. What would be the easiest, lightest, smallest ways to e.g. turn on a warning LED or buzzer (using the same battery ...
0
votes
1answer
70 views

How much battery power for LED and how to make it flicker [closed]

I am trying to figure out what configuration of battery(ies) I need to power this LED. I am only using one (specifically the warm white 1-up). I am also looking to make it flicker like a candle with ...
0
votes
1answer
81 views

Comparator loses voltage when connected to mosfet

I want to make a discharger for 18650 batteries so I can store them at a specific voltage. I built a comparator (LM393) with a voltage reference to 3.8V at the inverting input and the voltage of the ...
6
votes
2answers
257 views

Can the negative impact of mixing new and old batteries be mitigated?

Mixing old and new batteries is bad. But there are various options how they can be mixed, and I guess there are use cases in which certain ways of mixing can be justified. In my off-grid solar ...
-2
votes
1answer
45 views

battery fully discharging [duplicate]

My goal is to use my laptop, a pioneer dj controller and 2 krk rokit 5's (50W class-AB amplifier boxes) for a party all at the same time for about 6-8 hours in a place without access to grid power. ...
-1
votes
1answer
35 views

Using a 7.4 V LiPo Battery for an Arduino Feather 32u4

I am working on an Arduino project at the moment, with the following board: Adafruit Feather 32u4 And it says I need 3.7 V of LiPo to power it. However I also have a valve that I want to open and ...
0
votes
4answers
75 views

How to reduce the current of a battery with an unknown maximum amperage

I'm currently trying to heat a wire to a certain temperature and tests showed that the amperage needed is in the range of 3-4 A. However, I'm having a problem with how to supply such current to the ...
0
votes
1answer
49 views

Charging a L-ion battery 3.7V/850mAh with terminal connectors

How do I charge a battery with a connector as shown in this link: https://uk.farnell.com/bak/lp-503759-is-3/battery-lithium-pol-3-7v-1300/dp/2077882?MER=bn_level5_4NP_LastViewed_1
0
votes
3answers
129 views

Low temperature batteries for use in Arctic

I've been checking the forum and Google but still haven't got precise solution to my current question. In short, we are looking for rechargable batteries for Arduino that survive under -40 Celcius ...
0
votes
1answer
21 views

Under-voltage lockout programming on Delta D12F200 DC/DC converter

I recently decided on the Delta D12F200 DC/DC converter for my current project (datasheet: https://www.mouser.com/datasheet/2/632/DS_D12F200-1141659.pdf). My project will be powered by lithium ion ...
0
votes
1answer
146 views

BQ2002 NiMH Charging Circuit not working

I have the following charging circuit based on the BQ2002 which will charge a NiMH battery using a 5V micro USB cable. I built the circuit already and noticed that the TIP32C is not getting hot and ...
0
votes
1answer
31 views

How to find time constant of battery first order model with unknown capacitance?

The above picture is the first order circuit model of battery. I'm trying to calculate the value of R1 and C1 with specified time varied input and output. In order to calculate that, I have to know ...
0
votes
0answers
47 views

Short circuit protection of lithium pouch cells in parallel

I want to put together a battery pack with 2 or 3 lithium pouch cells (for example SLPB11543140H5) in parallel, and a few more in series. Of course they have to have some kind of short circuit ...
0
votes
1answer
76 views

Circuit to save one battery when another battery is present

I have a battery powered system and I want to preserve the test batteries during setup and calibration. I want the system to use the setup batteries if they are present and use the test batteries if ...
0
votes
1answer
76 views

How to unite three different batteries in to one powerbank [closed]

I'm absolute beginner in electrical engineering and I need help in building a powerbank using three different batteries with different characteristics. I have a sudden passion to implement this ...
0
votes
2answers
95 views

What battery size/type should I use (and wiring tips for LEDs?)

My son and I are designing a 3D printed body for his pinewood derby car. We want to add some colored LED lights. I found some lights that I think will work well, from a mechanical fit and looks ...
0
votes
2answers
45 views

do the voltage and amperage applied to a motor matter as long as the wattage stays at what its rated for?

I have an electric 180w motor from an electric go cart which currently runs on lead acid batteries but I want to convert it to have a 18650 battery pack for a power supply but I cant find the rated ...
0
votes
0answers
56 views

Dummy battery Solution - battery counter

I'm currently working on a project that will (hopefully) incentive people to stop using disposable batteries. To do that I'm thinking on creating a dummy battery that will allow you to plug a ...
0
votes
1answer
27 views

LiPo Battery Charger

I'm working on a portable PCB using a 3.7V 500mAh LiPo pouch cell. It's designed to be as low powered as possible (under 150uA). I came across the TP4056 however power consumption is too high for it. ...
0
votes
1answer
91 views

Lithium Pouch Cell Expansion [closed]

I am planning to use the SPIM08HP pouch cells from batteryhookup.com for their crazy power. They have an extremely high discharge rate at 25c, but I have heard that under heavy load, pouch cells will ...
0
votes
1answer
94 views

Identify these components for bluetooth speaker [closed]

I am wanting to make my own DIY bluetooth speaker (first time electronics project) and I have found several good Youtube videos on the topic. However when it comes to finding the actual parts, I am ...
0
votes
0answers
66 views

Accumulation of batteries' energy to rise electrical power capability

I am looking for a method to drive/pulse (ocasionally) an inductive load from a battery. The problem is, that the battery does not deliver enough power the load needs. But, energy is not a problem. I ...
0
votes
1answer
48 views

Flooded lead acid batteries in series and parallel - voltage drop at negative terminal

This question is a continuation of my previous question : What is the best way to combine multiple batteries (flooded lead acid)? I have a battery bank of four 150 Ah 12 V flooded lead acid batteries ...
0
votes
1answer
101 views

Solar charge set up damaging battery?

I've installed a 12V 80W solar panel plus controller and attached it to a 12V 105Ah leisure battery. At first it (appeared to?) work. The charge status on the solar charge controller was at max and it ...
0
votes
2answers
56 views

Confused on voltage potential

I’ve been doing much research the last couple of days about electricity. I have a pretty good understanding of Watts, Joules, Coulombs, Amperes, Ohms, and I know Ohms law finding voltage and all and I ...
0
votes
1answer
36 views

li-ion battery managment system, cell protection difference?

Could you help me to clear up what the battery management system/BMS adds to cell level protection, what is the difference? I assume that if I have many cells in series if I only have cell protection ...
1
vote
2answers
108 views

Replace 3.7V flat tablet battery with a 18650 cell

I am building a device using cheap Chinese tablet. One of the problems I have is weak built-in battery. I'd like to replace it with a few 18650 cells. As far as I know, 18650 cell can be charged up ...