battery charger

  1. Amir Mohammad Soltanpour

    Variable Current Lead Acide Battery Charger

    Digitally controlling charge voltage with some regulator like Lm317 is a matter of using some resistor and transistor as stated in lm317 datasheet to select from multiple pre defined voltage. But what about choosing output current ? How it can be adjust with digital signals from...
  2. O

    battery charger not happy with a long wire connection

    I have a Chinese battery charging control module (XH-M603) that I'm trying to use as a float charger for a 12v SLA battery. The problem is that the module only works correctly when it is connected close to the battery using short leads. When I connect the module using 30ft of wire (which is how...
  3. D

    Question about charging two 18650 batteries

    Hello! First time ever posting to a forum of any kind. I have a charger made for charging a single 3.7 volt Li-Ion battery or more than one cell could be charged but at a slower charge rate. My question is there anyway to charge the two cells ran in series as the picture I attached shows with...
  4. M

    Battery charger and MPPT controller

    I am working on a project where i have to charge a battery from a PV panel source. I have a boost cascaded by a buck converter for my system. The boost converter for P&O MPPT and the buck for the 3 stage battery charging algorithm. So now I am looking to implement the control. So on a...
  5. D

    Keep running circuit while solar charging

    Hi All, I would like to build a simple automatic irrigation system with Raspberry Pi zero, the thing is that I don't have access to electricity outside. I thought to connect 5v solar panel + 3\4 chargeable batteries. Im not that familiar with building control circuits for charging batteries...
  6. 3

    Solar charger & timer

    Hi I need help building the electronics for a home project. Essentially I am trying to: 1. Charge a battery with a solar panel 2. Activate a 12solenoid valve controlling pressurized water with a push button 3. Have the solenoid close after an adjustable time delay I was able to find solar...
  7. vmazsit

    Making a lamp portable with 18650

    Hey! I have a lamp which is powered by a 5V power supply and I want to upgrade it by powering it with a battery pack. The issue is I want to use the lamp while charging its batteries but as I know charging and draining at one time is impossible so I searched for simple switching circuit but I...
  8. I

    Head Light Bulb Kit and Li-Ion Battery Pack

    Hello, I have lithium-ion battery pack that consists of 21 cells( 3 parallel,7 series,one of them 4,2V 3.4Ah). I use this battery pack with BQ7791504PW from Texas Instruments for battery protection.This IC achieves pack protection via CHG and DSG low-side NMOS FET drivers. I use this battery...
  9. Nikolas_

    Battery charger circuit design

    Hey, so I am trying to design and build my own battery charger for 4 cell LiPos (including HV-LiPos with 4.35v/cell) but I don't have a lot of experience with circuit design. I designed this circuit so that it can either supply a constant voltage or constant current to the battery with the...
  10. Rahulk70

    Fast acting device to protect a high current 6/12V charger during short circuit?

    Hello, Which device best protects the rectifier and electronics inside an older style car battery charger? I have seen some manufacturers use an ATC blade fuse but I'm not sure if that will act fast enough to protect the circuits. I came across another device too, it's a Bussmann Circuit...
  11. jhon15

    How to calculate Rt1 and Rt2 of the MCP73833 IC ?

    I'm developing a battery charger with the MCP73833 IC. I want to set up the charge temperature window between 0 °C - 60 °C . How can I calculate Rt1 and Rt2 ? The equation: The datasheet: Datasheet
  12. A

    Circuit board help

    I have a wireless keyboard case for my iPad mini. When it’s off and I put it to charge the charge light turns on. But when I turn on the keyboard it’s dead. I’m looking at the circuit board and I think it has to do with the battery. The board looks fine. Can someone help me ?
  13. P

    Li-ion battery charging termination current

    Hi all, I have a question about Li-ion rechargable batteries. I have almost no experience with it. Documentation to battery is very poor, but there is an info about charging profile: Stage 1: Constant Current 0.82 Ampere (0.2C) until Voltage reach 4.2V Stage 2: Constant Voltage (4.2V) with...
  14. T

    Building a charging circuit for a 2 cell Li-ion battery

    Hi, I am in the process of designing a battery to use with a pair of FPV goggles for drone racing, the goggles require a 2 cell battery, but I don't have a 2 cell battery charger. I do have a bunch of TP4056 charging boards, and I was looking to design an all in one unit that would hold 2...
  15. P

    Running a power tool without a battery.

    Hi, I have a 10.8V Bosch battery which is standard for power tools. It has 5 terminals: + - C1 C2 T I'd like to power the device without the battery using a DC power supply. When I apply just the right voltage to + and - it doesn't work. How am I supposed to mimick C1,C2 and T interfaces...
  16. Carlosonline

    Li-Ion Battery Managment IC Issue

    Hi, I would appreciate if someone would be able to comment/advice on the following matter. I have been looking around for an IC that would charge and balance Li-Ion cells 2-3 of them in series. It seems that the balance feature is absent in most cases. MCP73841 appears to provide most of the...
  17. B

    SLA Battery Charging/Maintenance

    Is using a UPS i.e. APC Smart-UPS (4 battery) a recognized way to charge and maintain SLA batteries (AGM) throughout the year? Given that the batteries should be discharged about every 3 months?
  18. R

    Arduino Mega 2560 controlled MPPT charge controller for small wind turbine.

    I am in the process of designing a MPPT controller for a wind turbine. There are plenty of MPPT boards (with BQ24650 MPPT charge controller ICs) but these are fixed voltage MPPT designs tailored for photovoltaic applications. So I decided to make a simple DC converter (buck boost design, non...
  19. J

    LDO crash when Lipo reaches full charge with USB still powering.

    Hello, I'm just now getting into creating PCB's as a hobby, and created a little board that simply consists of a BLE module powered by a tiny Lithium polymer battery (40mah). Since the max operating voltage of the module is 3.6V, I also have an LDO that will drop the voltage down to 3.3V...
  20. P

    Need to Design 48v to 12v DC 10A Max Circuit

    Hi, I need to design a DC DC Converter Circuit: 48v to 12v DC 10A Max Current with Isolation. Anyone, please share reference design/Schematics if any.