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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

459 questions with no upvoted or accepted answers
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votes
1answer
537 views

Lifepo4 current limiter with supercapacitor in parallell

I am making a LiFePo4/supercapacitor-hybrid. Spike current draw can reach 300A for a few seconds. The LiFePo4 batteries I am using is rated for 100A max discharge rate. In order to make sure the ...
3
votes
1answer
61 views

Advice for a Solar Charger and Battery Project

I am a high school robotics teacher (no formal engineering training) and I am taking a group of students to Kenya this summer to work with high school students there. The organization we are ...
3
votes
0answers
103 views

Power use question for a trail camera

I am trying to calculate how long that a trail camera can be deployed before the batteries run out. The trail camera in question is a Reconyx HyperFire 2. Here is a useful review of the trail camera ...
3
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0answers
69 views

Can I extrapolate battery power by a brief observation?

Part of the research we are conducting requires us to estimate how detrimental our proposed algorithm to the battery life of the wearables. To do so, I opted to simply charge the wearable to 100% and ...
3
votes
1answer
744 views

Many questions about charging a lead acid battery

Well, I have a 12V 9AH SLA Battery, and I use a 7815 + a diode in series to charge it, (I really wanted to build a charger using the L200 or the LM317 but I couldn't find any of those in my city). So, ...
3
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1answer
555 views

Proper way of designing a battery backup system with 12V/5V dual output AC power supply?

I have a project (doorlock) with MCU / LCD / Keypad and solenoid (lock) connected together. MCU, LCD and Keypad runs at 5V while solenoid runs at 9V to 12V. I'm currently powering the system with an ...
2
votes
0answers
48 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-...
2
votes
1answer
60 views

Battery choice: Effect of “pulse current” and “continuous current (maximum)” rating differences

I am trying to understand the consequences (if any) of substituting a CR2450 battery for the specified CR2340 lithium battery in a small device. The device is constantly "on" and transmitting a ...
2
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0answers
75 views

Sense resistors in system-side Li-Ion charger/gauge circuit

I'm working on designing a charger and fuel gauge circuit for a premade 3S3P Li-Ion battery pack. The battery pack has basic protection circuits onborad (over/undervoltage and a PTC) and only the pack ...
2
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1answer
124 views

One Way Current Restrictor

Will the below circuit act as a one-way current restrictor to allow 100A to flow out of the battery, but limit charging current to 10A into the battery from the alternator?
2
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0answers
29 views

Context of Li-Ion MnO2 “Cell Configuration” Specification

My application supports variable pack configurations: 4S4P, 4S6P and 4S8P. Each one obviously uses a different BMS profile, and other minor changes such as charge/discharge MOSFET and fuse selections....
2
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0answers
527 views

DIY 4S Li-Ion battery pack

I am in need of some help designing my battery pack. I have a few concerns, mostly around charging. My plans consist of using a microUSB boost converter to bring the voltage to 16.8V for charging. ...
2
votes
0answers
162 views

How can I size the current ripple of a DC-DC converter for lithium batteries

I am designing a bidirectional DC-DC converter to charge and discharge batteries on a DC bus. The power of this converter is 50 kW and the average current in the inductor (the same as that on the ...
2
votes
1answer
63 views

Does Quick Charge have an effect on battery lifespan?

When charging my phone (a Samsung Galaxy Note 4 using a 3,220mAh lithium-ion battery) I have the option of charging it with with a standard charger or a Quick Charge 3.0 charger. Quick Charge is a: ...
2
votes
2answers
167 views

Switch from one battery to another when one is discharged/disconnected?

I'm trying to figure out how to switch source power from one battery to another when one is dead or disconnected. the circuit needs to be able detect the loss of power on the jettisoned battery and ...
2
votes
1answer
377 views

UPS battery as auxiliary power supply for car - charging and detecting car on

I'm designing a arduino-based car system that I would like to have running even when the car is off and parked. Though the system is designed to be very energy efficient, I don't want it to run down ...
2
votes
1answer
169 views

Problems when powering a circuit directly from Solar Panel

Am working on a project which uses Solar panel to power the project. I have a 12v 5w Solar panel to use for this purpose. And am thinking to remove the battery from this project since I feel that ...
2
votes
1answer
721 views

Proper way to recover 18650 cells from laptop batteries

I'm looking for a tutorial on how to recover 18650 cells from laptop battery packs. Like what should I do, and what should I not do, how to test them to see their condition. The way I'm doing it now ...
2
votes
1answer
1k views

Batteries connection to load and charging port for DIY bluetooth speaker

it is my first question here, so I hope to write this in the right way. What I'm trying to accomplish is buidling a battery powered bluetooth speaker. In order to do it I'm using the following parts: ...
2
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0answers
163 views

How separators prevent electrons from passing through

Separators (polymers) in batteries keep electrons from passing through but they let ions through. How do they do that if electrons are smaller than ions? Can we imagine it as a kind of 3D wire mesh ...
2
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2answers
1k views

Schematic for a lipo battery bleeder overcharge protector

OK, so I am building a 12v (really 11.1v) 10000mah lipo battery. I am going to use it on campouts to run things like 12v fans and car chargers and run other high-current devices that couldn't be run ...
2
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0answers
334 views

Lead-Acid Battery Desulfation Circuit Design:

I'm seeking ideas for making a pulsing lead-acid desulfation circuit design. Several circuit designs are available via Google image search, however, I'm hoping to get some help here to design a ...
2
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0answers
1k views

UL Testing for low voltage battery powered devices

Is UL Testing needed for a 3.6 V battery powered device that is totally enclosed in ABS platstic with no electrical terminals outside?
1
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1answer
79 views

Will my DIY powerbank be safe? It will be charged using laptop chargers

I want to build a DIY power bank that can be powered using most types of laptop chargers. I do not have any background except personal interest and lots of videos and documents read online. I need ...
1
vote
1answer
52 views

Why has the XBOX360 controllers battery pack an integrated breaker contact

Everyone owning a XBOX360 with wireless controllers came across a phenomenon where older controllers were switching off randomly while playing or if they were moved too quickly. Me and everyone i know ...
1
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0answers
29 views

LCD Dimmer with Variable Resistance Circuit

essentially I'm trying to make a very basic circuit where a 3.7 volt battery is wired to a liquid crystal display, (or LCD), and the brightness of said display is controlled by a pentiometer to ...
1
vote
1answer
118 views

Replace mains 12v power-supply with 12v battery

A Yamaha digital piano is powered by a mains power-supply. The power-supply states the following input/output values: INPUT 100-240V~50/60Hz 0.5A OUTPUT 12V === 1.5A (Where I have written === there ...
1
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2answers
97 views

Vehicle Alternator/Inverter system

I have a food van with a stock alternator on the engine, and a 3000w inverter setup. The inverter setup uses 2 Trojan leisure batteries. Somehow the inverter setup is also linked to the alternator (I’...
1
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0answers
62 views

Battery Monitoring IC communication via SPI

I am trying to use Max14921(Battery monitoring system) to measure voltages of 16 cells of a battery pack. I have used stm32f103c8t6 as mcu. The problem is that I could never communicate with IC. I ...
1
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0answers
52 views

How do portable batteries with AC outlets handle the ground pin/wire?

There are many portable batteries ("power stations") that have AC outlet(s) with – what looks like – a dummy ground pin. From what I can find in their manuals, it doesn't seem like these devices are ...
1
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0answers
62 views

Is it possible to somehow revive an AGM battery, that quickly loses voltage when used?

I have a GLP 120-12 AGM battery, this thing to be exact: https://glpower.eu/produkt/glp-120-12/ It's a 120 amps battery, and it is about 26 months old. All of a sudden, I noticed that the battery is ...
1
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0answers
50 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 ...
1
vote
1answer
52 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
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0answers
42 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 ...
1
vote
0answers
34 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 ...
1
vote
1answer
51 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. ...
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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 ...
1
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0answers
93 views

Lithium battery performance in cold temperatures powering BLE Beacon

I am working on a project that requires the use of BLE Beacons in very low-temperature environments, on average -15°C but on occasion as low as -25°C. We are currently trialling a brand of BLE Beacon ...
1
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0answers
34 views

Protecting Copper Anode in 12V DC System

Getting to grips with cathodic protection here. If someone had a 12, 24 or 48VDC system, say solar PV and batteries, and the battery negative is earthed, this means the earth is the cathode, and the ...
1
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0answers
57 views

help building 6S2P balanced Li-Ion battery pack

I'm trying to build a 6S2P balanced Li-Ion battery pack for a quadcopter using LG 18650 HG2 cells with pre-soldered nickel strips (1st image) so that I won't solder directly on the cell's terminals. ...
1
vote
1answer
179 views

Can I make endless parallel li-ion connections?

I'm looking into building my own li-ion battery pack. I read about linking the cells in parallel and in series, and how to add a BMS. I would like to build a 12V pack with a very large capacity (mAh)....
1
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0answers
59 views

Usability of a deeply discharged Li-ion batteries

I have a question about Li-ion batteries. About three years back I bought two Sony VTC 5 batteries for my vape. They are rated as 2500 mAh 30 A. But I quit smoking about a year ago and I left these ...
1
vote
1answer
107 views

Reverse Current leak Battery+Diode in parallel

on my design, I am using two coin batteries in parallel and each battery has a Schottky diode in series to block the reverse current, in theory, it will avoid the higher potential battery "charge" the ...
1
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0answers
36 views

Battery Powered System and Input Capacitance

I have a battery powered system in which the battery is connected to a buck/boost converter to derive 3.3V from two or three AA batteries. The regulator I'm using is a TI TPS63050, and it has a power ...
1
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0answers
83 views

How to disconnect 3.7V battery when USB is connected (boost)

I am developing a circuit which enables me to charge a lithium battery and boost the output voltage up to 5V for a microcontroller. My boost converter is the MT3608, and the charging circuit is the ...
1
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0answers
49 views

Powering refrigerator using solar inverter

I have got a 3 kVA (2400 watt) solar hybrid inverter (pure sine wave) which is connected to a 1280 watt PV array and 2 x 12 volt 150 Ah batteries. It is supposed to switch to utility mode if the ...
1
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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 ...
1
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0answers
32 views

Responsible Battery Reserve Capacity and Low voltage?

It's been asked here, but looking for clarity. How bad is it to undervoltage a 12-volt lead-acid battery? SLI automotive starter batteries list RC (reserve capacity), but I think this a usable ...
1
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0answers
64 views

Charge a 12V marine/boat battery with AC

need to build a diode bridge to recharge a battery (car/boat type) from a boat engine that gives 12V AC. I thought of doing something like this: simulate this circuit – Schematic created using ...
1
vote
2answers
356 views

How to use CC/CV Charger with a DC/DC converter

I am searching for a solution to charge a battery pack (7S1P)[ICR18650] with a charger with CC/CV mode and I have a BMS for protection (I've done research to maximise the security of the battery pack)....