Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [bms]

A battery management system (BMS) is any electronic system that manages a rechargeable battery (cell or battery pack)

230 questions
12
votes
4 answers

Is there way to construct an 18650 battery pack with built-in balance charging? Or is balancing not very necessary?

I am a DIY enthusiast, especially in electronics. I'm currently building a portable Playstation 2 Slim with an IPS display, so that it would look like a Wii U controller. It's my first large electronic endeavor. However, being portable, I'd need it…
Paolo
  • 143
  • 2
  • 2
  • 8
5
votes
1 answer

Question about an electronic component which could be a fuse

i have an old laptop from which i removed the battery in order to repair it. There were 6 cells in total and 2 of them were bad. One of them was leaking cellfluid when i tried charginging and reviving it. The other 4 cells seem fine. I fixed the…
abdussamed17
  • 101
  • 8
4
votes
1 answer

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 capacitor topologies are expensive but passive…
Shamurov
  • 143
  • 6
4
votes
1 answer

Solder reflow pure nickel strip to PCB ENIG pads

I've arranged for a custom shaped strip of pure nickel that I intend to solder to ENIG pads on a PCB using reflow/paste. Will we have problems getting the solder to adhere to the nickel? Is there a trick to it? Other (potentially relevant)…
Dan
  • 133
  • 8
3
votes
2 answers

BMS for two parallel protected 14500 Li-ion batteries

I have two li-ion 14500 850mAh protected 14500 Li-ion batteries and a BMS 1S (for example) I would like to connect the protected 14500 Li-ion batteries in parallel in order to get more current (for twice longer use) Thought of connecting BMS (mostly…
user1673206
  • 243
  • 1
  • 6
3
votes
1 answer

Could I use a 5-S BMS with only 3 cells?

I am analyzing an open-source BMS project based on a BQ76920 from Texas Instruments and checking its datasheet to understand their features and applications. The schematic of the project seems to be consistent with the datasheet but my question…
imt_blake
  • 325
  • 10
3
votes
1 answer

DIY Power pack - Is my circuit right?

I'm a beginner in electronics and I have some questions about the diagram I made. Do you have a recommendation for the charger? Or is it easy enough to build one? R4 is needed or not? I don't know because of the presence of R2. The voltage divider…
Mathieu
  • 31
  • 4
3
votes
1 answer

Modify existing 18650 4-cell Li-ion battery pack for higher capacity

I have a 4-cell 18650 battery pack that currently has LG M26 INR (Li-ion) cells rated at 2600 mAh and I want to replace those with LG MJ1 INR cells rated at 3500 mAh and having the same voltage and discharge current specs (max. 10 A). The battery…
C C
  • 133
  • 4
3
votes
6 answers

Repairing a 5-cell Li-ion battery: dead 21700 cells replaced, but BMS still reporting error when charging

I have been given a small portable vacuum cleaner with a faulty battery. The battery is an 18 V, 5-cell 21700 unit with a large BMS board on top. One cell wasn't reporting voltage so I replaced it with a brand new cell of the same spec (Samsung…
JohnnyVegas
  • 349
  • 2
  • 10
3
votes
1 answer

LM22673 diode selection

I'm fairly new to electronics, and in my project I'm using LM22673 as Buck Converter in this Diode selection parts this is given which is confusing for me. as Ultra-fast diodes can switch very fast, so what's the issue with that? How it will…
navi
  • 166
  • 6
3
votes
1 answer

BMS design question

I recently came across this popular BMS design and I am trying to understand the circuit design There are some great technical discussions around it, like on robojax or this non-English forum. Most parts are pretty straight forward. Below is my…
Chung Hoàng
  • 31
  • 1
3
votes
1 answer

Is a battery pack connected parallelly or in series?

I have a circuit of a battery pack of 4 18650 and a 4S BMS. See the picture below. The question is: is my understanding correct that this circuit means that the batteries are connected in a series, so the output from BMS should have 6.7 A current…
pascalamin
  • 51
  • 2
3
votes
1 answer

Smart BMS UART problems

I recently bought a Daly Smart BMS from China for an EV project. It works well but we can’t communicate with its UART port. I got the pinouts and protocol from manufacturer and connected it to an Arduino mega serial port. It echoes back anything we…
yigitabi5444
  • 31
  • 2
3
votes
1 answer

Connecting BMS to charge controller and load

I'm trying to design a circuit that lets a load will get power from a solar panel or a battery (in case the solar panel is not delivering enough power). The question is about connecting the charge controller and the BMS-2S to the load. 1. 12 V solar…
user1673206
  • 243
  • 1
  • 6
2
votes
0 answers

Battery thermal protection circuit

I'm trying to design a circuit to be used with some 12V LiFePO4 battery packs which don't have an integrated heater, so I can add thermal protection. The circuit would sit between a 65W solar charge controller and the battery's existing BMS. It…
davegravy
  • 319
  • 2
  • 8
1
2 3
…
15 16