Questions tagged [cell-battery]

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1answer
118 views

Building a Huge 18650 Battery Powerbank DIY [closed]

I know there are a lot of threads about this topic already, but I still have some questions about it. Anyways, I am thinking about making a 50-80 thousand mAh power bank depending on the batteries and ...
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1answer
60 views

How bad are 3 degrees Celsius for a lithium battery and electronics?

I have a PCB powered by a lithium battery , it works well inside the house, but when I leave it exposed to low temperatures with humidity the PCB or the battery stops working. I leave the PCB in the ...
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1answer
62 views

Do standard NiMh AA or AAA battery's have any kind of BMS or protection circuit built-in?

Do standard rechargeable NiMh AA or AAA battery's have any kind of protection circuit like over discharge? Or are there any circuits out there that do that kind of stuff? I want to power my Arduino ...
5
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2answers
159 views

How to efficiently read a battery voltage level with ADC

There is a circuit powered by a battery (3V button cell) and another circuit with a microcontroller (Attiny85 in my case) reading perfectly the battery level (through ADC3 pin) each 5 minutes interval....
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1answer
62 views

how the battery behaves in this diagram

My question is this. I'm using this ic mppt SM72445 along with a 250 watt solar panel, mppt output configured to 50.4 or 51 volts, 12-cell lithium-ion battery pack and bms, if the load is less than ...
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2answers
73 views

how a battery behaves in parallel to the charger with a shared load but with a voltage difference

how the battery behaves in this diagram how a battery behaves in parallel to the charger with a shared load but with a voltage difference
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0answers
38 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 ...
1
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2answers
96 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 ...
1
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2answers
75 views

Switch battery usage off when jack 3.5mm is not inserted

I have an ongoing project where I'm using a condenser microphone to record various stuff, it's powered by a CR2032 battery and the output of the microphone is directed to a TRRS jack connector (3.5mm),...
2
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3answers
87 views

Peak TX current of LoRa RFM95W

I'm running into some issues powering a test board using a LoRa chip (RFM95W) with a CR2032 battery. I'm well aware of the peak current limitation of such battery and I can see a major voltage drop ...
0
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1answer
30 views

Thinkpad 420 battery not charging despite of Cells inside are good [closed]

My thinkpad 420 battery is not charging. So far I have done following. Put another battery in my thinkpad and it is charging perfectly. Opened the defective battery and checked all three sets of 2 ...
1
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1answer
163 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)....
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0answers
39 views

Charging Voltage of Lead Acid Batteries

I recently installed a solar ups and it has been charging the batteries all the time. I have two 12v 230ah Batteries (lead acid tubular) in series and my solar charger software says that it is ...
0
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1answer
47 views

Battery Protection IC in Series

I want to make a project to protect each individual cells of 16 series battery pack. I have read some data sheets of battery protection IC's such as BQ29209DRBR,S-8261,AP9281 etc. None of them clearly ...
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1answer
116 views

How to measure battery capacity?

I hope this is not off topic. Consider I buy brand new 12V battery. Normally, will be 13.8V when it fully charged. According to the info written in the cover, it capacity is 42Ah. After used for ...
-3
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1answer
101 views

Calculate battery discharge time to a certain voltage value [duplicate]

Let's say I have a 14.8V battery with capacity of 5200mAh. My load constantly draws 20 amps from it. I want to estimate the time it takes until the cell reaches let's say 10V. This is just an example, ...
0
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2answers
420 views

Charging 8 LiIon 18650 cells in parallel

I'm working on project that is Powered with 8 LiIon batteries/cells connected in parallel. Everything Works fine until batteries run out of "juice". For charging module I decided to use TP4056(@ 1A). ...
-1
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1answer
82 views

Building a LiPo battery pack for output 270v DC

so this is related to my other question if anyone wonders. I’m building out a EV battery pack to boost charge a vehicle in real time during heavy duty cycles. The vehicle currently has no external ...
0
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1answer
52 views

Battery Management System (BMS)

Suppose that a lithium-ion cell having total charge capacity Q=10Ah is discharged at a rate of 1A for 30min. What is the net change in the cell's state of charge (in percent)? Round to the nearest ...
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2answers
84 views

Security/safety circuits in removable cell phone batteries?

It seems like the aftermarket phone battery is so flooded with terrible counterfeits it can't be too hard to trick a phone into thinking a battery is genuine. I'd really like to learn how to use an ...
1
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1answer
290 views

LiFePO4 cells - self-balancing in series or parallel?

I am building various banks / packs from individual prismatic LFP cells, nominal 3.2V each. New and pretty large, 60-400AH. I have a good power supply, charge each cell independently, Bulk stage CC ...
0
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1answer
47 views

run ac device on battery [closed]

I recently purchased a radio which unfortunately doesn't have battery option. Its spec is AC 230V - 50/60 Hz and 14 W Is there any way to use my Ni-Mh rechargeable cell battery with this device. ...
0
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2answers
284 views

Calculate the Li-ion battery remaining capacity

How can I calculate the remaining capacity (exact or approx value) of a Li-ion battery by measuring its voltage. The battery is connected the load and i know only the battery voltage and the value of ...
0
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1answer
145 views

Battery Balancing system [closed]

I am trying to build a Battery balancer system for 16S8P battery pack.It consist of li-on cells(NCR18650PF). I understood how serial balancing is working properly.If serial cells are not equal,an MCU ...
1
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1answer
31 views

Increase working hours for an external speaker

I have an external speaker which uses one 18650 cell (3.7V). I would like to increase the working hours by adding one more cell of the same type. I have two questions: Should I add the second cell in ...
0
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1answer
91 views

Factors to be considered while replacing dead cells with a new 18650 Li-Ion cell in a Laptop

I am currently using a Lenovo Z50-70 laptop. My battery condition is very poor and it lasts for only 20mins. So I decided to replace the dead cells inside the laptop battery on my own. My Laptop ...
-1
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1answer
31 views

Li-ion Modded Powerbank Question

So I got this single Li-ion power bank. It's a 18650, and I wanted to add another 18650 in parallel. I want to use the same circuit which produces a constant 5v. Is it safe to do it that way? in ...
1
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1answer
108 views

How to connect a CR2012 coin cell battery with a PCB?

Im trying to build a flat, battery powered PCB assembly that fits into a small gap of approx. 2mm. I have found the CR2012 coin cell with a thickness of 1.2mm, which would be a good fit in terms of ...
0
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2answers
120 views

In Impedance track algorithm, How is resistance is related to soc(state of charge)?

In impedance algorithm for battery capacity, why we are calculating impedance and why it important to know impedance for SOC(state of charge)? 2.I doing some research on algorithms which we have,so,...
1
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1answer
107 views

How to calculate capacity of a battery from the readings of current and time?

The requirement is to compute the capacity of the battery in order to calculate the capacity degradation. The input which can be acquired are current, voltage, relative time, battery level (in terms ...
1
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0answers
45 views

battery life of rechargeable lithium battery

I am trying to determine the life of a lithium rechargeable battery (approximation) before a complete replacement is required. From Panasonic's datasheet, I see that at avg. 10% discharge, it is rated ...
1
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2answers
159 views

Running case fans on D cell batteries

I'm moving into my car and I may need to wire up ventilation that doesn't depend on the engine running. So I found these case fans. However, because I'm not going to be using the car battery, I need a ...
-4
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2answers
194 views

Charging 4x 18650 Li-Ion Batteries in series [closed]

Hello StackExchange community. So i have been for a long time wanting to build someything portable and recharchable with the 18650 batteries. the only problem is i cant find any good guide on how to ...
1
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2answers
86 views

Can you discharge a 3s LiPo battery from both its main plug and it’s balance plug?

So I’m building a quadcopter, and I want to be able to use the same battery to power both the escs and the flight controller. However, the escs are connected to the PDB which is connected to the ...
0
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1answer
177 views

Connecting battery cells in series VS using boost converter

I need a dc output of 12V 60AH through 18650 li-ion battery cells to use with a 1000W AC inverter to power a 650 Watts computer ( each cell 3,7 Volts 3500 mAh ) One way would be make 17 packs in ...
1
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3answers
113 views

How to find out which end of a dead battery is the anode, and its voltage [closed]

The battery pack for an old rc car I played with as a kid, has died. Salt crystals everywhere, smells like vinegar. The pack consists of 8 batteries of AA-size connected in series. The red markers ...
3
votes
1answer
125 views

Need help designing an airplane legal battery pack

I know this is not really a technical question but it might also help other people like me who design products with batteries. If it doesn't fit here, then please tell me where I can ask to find a ...
0
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1answer
72 views

Button batteries vs 9V headache

I am working on an arduino controller project with a few attached components returning data e.g. gps and mini camera. All works fine with usb power or 9V battery. I tried using button cells in ...
0
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2answers
109 views

E-bike battery: upgrade 18650 cells [closed]

I have an e-bike battery of capacity: 4.3Ah (Li-ion). Specifications: http://industrial.panasonic.com/cdbs/www-data/pdf2/ACA4000/ACA4000CE285.pdf For charging, the label on battery says "Rating 25.9V ...
0
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2answers
237 views

Max Discharge Rate of typical Alkaline Button Cell Batteries

I have simple circuit that has some led diodes, 3 LR41 batteries and no resistor. By looking at this website, it seems their capacity is about 30mAh. But I couldn't find anywhere the max discharge ...
0
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1answer
79 views

Li Ion battery issue (voltage appears and disappears)

I built up a Rspberry Pi self-driving car and everything was fine while I collected data for the Neural Net. After NN finished its training, I want to test the system. At the beginning, everything was ...
1
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2answers
121 views

Making a 100 LED Lamp

So I'm still very new to electronics but I would like to make a 100 LED Lamp for fun. I got my hands on a few 18650 batteries yesterday so I decided to do this project. I thought it through but I am ...
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1answer
58 views

Can a cell phone battery be used in a power bank at 2A?

Can/will a lithium ion cellphone battery that can be charged at 2 amps safely discharge at 2 amps if used as a power source for a power bank? (Samsung galaxy S4 mini battery in particular) Edit: I ...
0
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1answer
55 views

Is the usual model for batteries still valid in the reverse direction?

We all know the usual (simplistic) model for batteries, that is, representing it by a pure constant voltage source in series with its "internal resistance". This is probably sufficiently precise for ...
0
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3answers
614 views

Sram battery backup

I don't have an option here in my country , No non-volatile sram and i need it for my project . i designed a circuit for that and need anyone's opinion if it's ok or need a correction .
1
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3answers
175 views

Can you build a battery from scratch which is able to make a computer run?

I'm learning about batteries and I'm really fascinated by this topic. I saw some online videos on how to build some "Voltaic Pile - like" batteries with coins and other kind of cells in different ways....
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2answers
118 views

Dead laptop batteries [closed]

I disassembled a dead laptop battery and found 6 AA size batteries interconnected. 5 of them still give 1.2V on meter. If I replace the defective one would the pack be usable again and would it keep ...
1
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1answer
122 views

Basics of battery charging and discharging [closed]

I am trying to understand batteries. 1) If I have a rechargable battery of 1.2 V 1000mAh, it means I can draw 1A at 1.2 V for one hour and the battery is said to be discharged ? Does "discharged" ...
0
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1answer
7k views

Identify the pins of the circuitry that resides within a laptop battery [closed]

My ASUS laptop battery stopped working all of a sudden, when it had no reason to (new). Windows says "Plugged in, charging" , but the battery always stuck at 0%. Before getting a replacement battery,...
0
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2answers
82 views

Li-ion battery voltage?

My laptop battery is assembled from 4 cells in series. And the voltage of them all is 16.5V, (on battery it writes 14.8V). Can one cell be faulty even then? Is this a sign that battery is faulty, ...