Questions tagged [cell-balancing]

Cell balancing is a method of designing safer battery solutions that extends battery run time as well as battery life.

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Active battery equalizer, max current?

I have two 2x12, 50Ah LiFePo4 batteries. Charged via 24V LiFePo4 charger Max current is 50A (By BMS). Real life: <15A discharge, 5A charge It is unclear, how to choose the right balancer, by ...
Vetal's user avatar
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Li-Ion BMS which protects parallel cells in addition to series cells

Background If li-ion cells are arrayed (series x parallel — S x P or P x S) to form a battery, it is generally recommended to manage parallel stacks of series cells (P x S) independently, such that ...
kando's user avatar
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Lithium Ion Battery : Cell Array Configuration (V.batt when converting to ≤ 4[V] )

Question I am seeking to array 6x 21700 lithium ion battery cells, leaving the option for: 1S • 6P (@ V.batt.nom = 03.7 [V], range: 02.7—04.2 [V]) 2S • 3P (@ V.batt.nom = 07.4 [V], range: 05.4—08.4 [...
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Can I "Stack" 2-Cell Li-ion Battery Balancers for a 4-Cell battery?

I'm building a project where I need an internal rechargeable battery. I've decided to go with 4x 18650 Li-ion cells, so I can change them if necessary, the 4x 18650'ies will be used in series, for a ...
WeirdWolf's user avatar
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1 answer
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Secondary Connection for Transformers in Active Balancer using LTC3300-1

I am currently trying to implement an active balancer based on the LTC3300-1 (I have proposed the diagram based on the directions in the datasheet) but, about the connection for the secondaries of the ...
imt_blake's user avatar
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Transformer connection for active balancer

I am currently looking to implement an active balancer based on the LTC3300-1 for a 3-S LiPo array but I am unsure with the transformers, the datasheet shows how to connect the IC for a 3-S array. I ...
imt_blake's user avatar
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How to design an establish a battery topology with a BMS and charge transfer ("active") balancing

I read several documents about building batteries (e.g., for photovoltaic systems). I still have questions. 1.) LiFePO₄ cells have an internal resistance of a few mΩ. If you connect two such cells ...
Sam Ginrich's user avatar
2 votes
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381 views

Lithium battery pack charge controller and balancer module function (HX-4S-F30A)

I tried to use this module for a 4S 18650 battery pack: Beside charge controlling it is supposed to balance cells and this is where my issue emerges. If I put some unevenly charged cells in the pack, ...
AKTanara's user avatar
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3 votes
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Modify lithium battery pack balancer

This is the lithium battery pack balancers available to me: As Robojax has extensively explained in this video, this module is capable of balancing batteries with 67mA current (4.2v/62ohm) that is ...
AKTanara's user avatar
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What is wrong with my charge-transfer balancing circuit for a Li-ion battery?

I am trying to simulate this balancing circuit. The two complementary pulses control MOSFETs and as the resonant tank works the capacitors(as batteries) start to balance and I used op-amps to measure ...
Shamurov's user avatar
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How does balancing via resistors work? Why isn't it needed inside of batteries?

I am building a hobby project - a sort of supercapacitor powerbank, where I basically connected twelve 500F 2.7V supercapacitors in series. Despite these capacitors being from same manufacturer and ...
Petr's user avatar
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3 votes
1 answer
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Is there any scientific proof that passive cell balancing can improve the life of a battery pack?

Passive balancing usually works only in the charging end area, i.e. when the cells of a battery pack are almost fully charged. In the case of those cells that have already reached the end-of-charge ...
Medi1Saif's user avatar
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What is the function of the Zener diode in this BMS schematic?

I am drawing the schematic of a battery management system (BMS) based on the BQ76920. The application circuit in the datasheet shows the MOSFETs for balancing the voltage of each cell: I compared it ...
imt_blake's user avatar
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Is this 4-s BMS a balancer?

I have been reading about BMS systems and currently looking for open-source projects to analyze them and learn more in practical application. The schematic is this and my interpretation is: -The same ...
imt_blake's user avatar
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What can I use to drive charge and discharge high-side N-channel MOSFETs?

I want to control the charge and discharge MOSFETs of the series cells balancing circuit. There is a charge pump to do that but I do not know how to design such a charge pump. Is there any source ...
Shamurov's user avatar
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Load current from two lithium-ion parallel cells

How do I calculate the current flowing from V2 into V1? I have two lithium-ion cells that are connected in parallel to a load R3. Let's say R3 draws 200 A. How much current will flow through NODE 1 ...
JoeyB's user avatar
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Voltage divison across capacitor when one cell connection is removed

In this image, the voltage read across capacitor C1 and C2 is 3.5 V, which is normal. When I remove the connection between resistor R1 and V1, then the voltage read by the IC across C1 and C2 ...
kishore kumar's user avatar
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What is the purpose of the clamper circuits here?

I've looking at cell equalizing circuits, and just because it's expensive to drive them with isolated drivers I have come across this circuit which does the same thing with simple clamper circuits: I ...
Shamurov's user avatar
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4 votes
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What type of active cell balancing is used in EV's?

I know that active balancing is preferred over its passive counterpart but what active balancing techniques are used in electric vehicles BMS? I also know that switched capacitor and resonant switched ...
Shamurov's user avatar
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what voltage rating do I have to observe at resonant frequency?

This is the schematic of the resonant switched capacitor cell balancing circuit. The problem is that at the resonant frequency when the capacitor and inductor impedances become equal and the total ...
Shamurov's user avatar
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2 votes
1 answer
188 views

What kind of MOSFET gate driver is required for cell balancing in BMS?

I want to drive these MOSFETs which will be in the cell-balancing circuit that is part of the BMS. What kind of topology for gate drivers can be suitable for this system?
Shamurov's user avatar
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LTC3300 active cell balancer - unreliable SPI communication?

I have been using the LTC3300 IC for a couple of years. I always observed unreliable SPI communication. I played with SPI timing and had the controller resend the commands until they get through... ...
Philtao's user avatar
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How to simply balance two parallel connected cordless drill 18v batteries?

I am fairly new to battery management systems. I am planing to use two cordless drill 18v battery (5A each) in parallel for an IoT project. For the time being, I've just coupled the batteries through ...
Sener's user avatar
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Is using a non-balance protected lithium-ion battery ok?

I am building a project where I use 4 stepper motors. Since they require a lot of power I am considering using a Lithium-Ion battery for them. This is what I was looking at: https://www.onlybatteries....
Ana Lovejoy's user avatar
2 votes
1 answer
218 views

PWM Controlled Resistance vs Resistor to minimize heat dissapation

I have a low-ohm resistor (7.5 ohms) connected to a MOSFET used for passive charge balancing. It is generating a lot of heat on my PCB. I can apply a duty cycle to the switching which somewhat combats ...
cs_eng_516's user avatar
1 vote
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76 views

Practical usage of Automotive BMS with Active Balancing

I work as an intern at one of top semiconductor companies and also in automotive industry. Since I'm assigned to BMS (Battery Management System) team as a concept engineer I'm constantly looking for ...
MucaGinger's user avatar
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211 views

Manually balancing Li-ion battery pack

I have a battery pack which is currently 13 series and 3 paralell. Cells are Lithuim Ion. I want to make it into 16 series and 4 paralell. As far as i know it's a very good idea to make the old cells ...
forferdeilig's user avatar
-3 votes
1 answer
307 views

Power adapter 12V for charging LiFePo4 12V battery with BMS with passive balancing

I have a project where I need to charge an Enerpower LIFEPO4 Battery of 12V 12Ah with BMS with an integrated passive balancer, protection against overcharge, deep discharge, over-discharge (...
Katja F's user avatar
1 vote
1 answer
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Powering the load while charging 3s 18650 battery with BMS balance charger PCB

I want to charge use this battery management system (BMS) balance charging board for charging and management of a 3s 18650 battery. The load and charging port is connected in parallel with power port ...
Abtahee Salekeen's user avatar
1 vote
1 answer
41 views

Could I get a second pair of eyes to check if this BMS can be used for charging?

I'm new to electric engineering and electronics in general, so as a first project I'm building a battery using 18650 cells (4S4P). I am aware of the risks when buying from Chinese suppliers on ...
Eryk Halicki's user avatar
0 votes
1 answer
204 views

Cell balancing of two batteries connected each at the output of parallel converters

I am developing a scalable energy storage application where I connect bidirectional dc dc converters in parallel and battery is connected at output of each converter. I am uploading a block diagram to ...
Kranthi Kumar Banala's user avatar
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2 answers
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I'd like to know if my own version of a cell balancer will do the job

I have two 3.7v cells in series to make a 7.4v battery. I want to make my own active balancer because I don't have access to buying any cell balancers. I'm using a transformer with 2n turns on the ...
Bongani Khumalo's user avatar
0 votes
1 answer
81 views

3S Lithium-Ion power solution for a project

I have a PCB that runs on 12V throughout the day and consumes 2.3A. The power is supplied for 12 hours using a power supply. The other 12 hours it must run on batteries that have charged during the ...
Bavly's user avatar
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1 vote
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281 views

How Charger and Cell Balancer work in BMS?

I'm currently working on BMS for LiIon 4S2P battery pack. Two core components I've choose are BQ77915 balancer and BQ2954 charger from TI. For now, I stick to example schemes from datasheets, but I'm ...
Pararera's user avatar
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0 answers
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designing a supercapacitor balanced charger circuit

I'm currently designing a super capacitor based emergency power supply for a system. The operating voltage of my system is around 10~12 V. Therefore I'm using 4 2.7V supercapacitors in series to gain ...
Anuradha's user avatar
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0 answers
180 views

Is it possible (feasible) to use a synchronous buck regulator for balancing batteries?

I need to build for a hobby project, a active balancing circuit for large number of LiIon series cells (90 cells). So it needs to be cheap but efficient :) (ie. not resistive dup). After lot of ...
yo3hcv's user avatar
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1 vote
1 answer
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Would this design for Li-Ion cell protection+balancing circuit work?

My team and I are currently trying to design a 2S2P battery pack for use in a CubeSat (student project). The pack is planned to be used with 30-40% depth of discharge for a total of around 5800 charge-...
Darius's user avatar
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1 vote
1 answer
426 views

Cell balancing in BMS

I have questions with respect to cell balancing please help me 1.when this cell balancing will occur is it when charging the battery or when any cell goes more then rated voltage. 2.can you please ...
Yash's user avatar
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0 votes
2 answers
219 views

Switch individual MOSFETs connected across lithium-ion cell for passive balancing

I am working on a passive cell balancing circuit using N-MOSFET. The cell voltage will be monitored by the micro-controller and it can also generate corresponding logic level signal according to over ...
power machines's user avatar
1 vote
1 answer
109 views

Battery Balancing Board Equilibrium Current?

I just bought some balancing boards for a Bluetooth speaker project and realized after the fact there are two different equilibrium current options. I bought both the 2S and 3S versions as I haven't ...
Hartman9's user avatar
2 votes
3 answers
545 views

What is the best way to balance supercapacitor cells at 700mA peak charging current

So I want to charge a stack of six series-connected super capacitors from a small 10W solar panel. The part number of the capacitors is TPLH-2R7/12WR10X30. https://www.tecategroup.com/products/...
user4574's user avatar
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1 vote
1 answer
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Which cell balancing method (active or passive) is best for low-voltage BMS (Battery Management System)?

As a beginner, I am going to design and develop a BMS (Battery Management System) for low-voltage applications (electric bike). So I would like to know which cell balancing method is perfect for low-...
Muthu's user avatar
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2 votes
3 answers
586 views

Nickel battery balancer

TLDR: The question is about retrofitting a balancer to the Ni-MH battery of an existing appliance (that doesn't trickle charge the battery), preferably in the way that will not require frequent access ...
611's user avatar
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2 votes
0 answers
154 views

Why bq76940 cell0 has two capacitors

I'm exploring bq76940 datasheet. I've found such typical scheme for cells connection: Why VC5-VC4, VC4-VC3, VC3-VC2, VC2-VC1 pairs have only one capacitor and VC1-VC0 pair has two capacitors? What is ...
ft232r's user avatar
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0 votes
1 answer
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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 ...
Link's user avatar
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0 answers
102 views

Mosfet Selection

I am designing Battery balance system for 16 series Lion(NCR18650) battery pack.I have decided to implement passive balance method.Battery cell voltages will be controlled by MCU and whenever a ...
Emre İriş's user avatar
2 votes
0 answers
389 views

Multi-cell Li-ion battery charging

I am trying to make a charger circuit for a battery pack consisting of 6 lithium ion batteries (cells) in series. Many battery charger ICs support multi-cell charging but do not provide cell balancing ...
Yosry's user avatar
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-1 votes
1 answer
195 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 ...
EngMarc's user avatar
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0 votes
1 answer
175 views

Balance charging battery pack one-half at a time?

I'm trying to wrap my head around how I need to go about balancing charging a few NiMh battery packs. I'm using a HiTec x4 charger, which supports balancing charging up to 6 cells at a time. However, ...
Reza Karami's user avatar
0 votes
1 answer
319 views

Simple Li Ion integrated Charger and balancer

I am currently working on a project, which should contain a Li-Ion battery pack in the form of 8 18650 cells in 4S2P. The main consumers of the build are a class D amplifier and a single board ...
Hendrik410's user avatar