1. EUrbanAutoTech

    If V = I x R then does it still "make sense" to refer to a battery's voltage when not connected to anything? As in I = 0..?

    I'm an automotive mechanic that specializes in electrical/drivability diagnosis. I like helping other techs get a better grasp on this aspect of our trade. Now imagine I'm with another tech and I have a battery and a multimeter in front of me. I measure the battery's voltage and get 12V. Me...
  2. F

    DW01A on pcb and integrated on lipo: double charging protection ... will it still work?

    I've designed a circuit around the tp4056 with DW01A and FS8205A included, as well as load sharing capabilities. beneath circuit is what i use (minus load sharing) now that i'm sourcing lipo batteries, i see most of them have a protection circuit already build in with the same DW01A and...
  3. T

    Electric toothbrush not working with other battery?

    I have a Braun oral-b pro 2000 toothbrush and with the original battery it now only lasts about 1 minute. I replaced the original 3757 Ni-MH battery with an AA size Ni-MH (higher capacity) battery and the red “battery low” indicator blinking. I had put it on the charger and it charged the...
  4. Svennn

    Wine bottle storage quality sensor thesis

    Good evening all, Background: I am final year Electrical & Electronic engineering student currently in the process of completing my undergraduate thesis. The thesis topic consists of making a low-cost, non-intrusive, battery powered electronic device that is small enough to fit in the punt (the...
  5. E

    3.3V battery pack / charging solution

    Hi folks! So I'm looking into the following, but having a very hard time finding any (remotely) definitive answers. For my smart home, I'm looking to integrate more and more sensors that can relay all sorts of information. Most of these sensors I create myself using ESP32's and the like...
  6. G

    Radio Control Airplane - Dual Battery Power

    Radio Control Airplane using a 20 cc gas engine with solid state ignition. Hall effect sensor used to trigger the ignition. Ignition has a shielded spark plug. I will be using 5 servos rated for 8.4 volts. Typically, they run with a 50 Hz signal, but different servos can have up to 400 Hz...
  7. A

    [SOLVED] Voltage divider 5V to 3V to replace 2 AAA batteries with DC power supply?

    I have this portable rechargeable battery pack for charging smartphones. It is 5V, 2.4A, and 5000mAh. I would like to use it to power a wireless mouse that normally requires 2 AAA batteries, which is 3V and I'm not sure what is the A and mAh. I made a voltage divider that involves a 220Ω...
  8. P

    AC/DC 24v power supply 5a with 8 barrel connectors?

    Hello, First off, I'm a newbie. Not sure if what I'm looking for is doable, possible... I have 8 battery powered light fixtures. They come with 24v, 5a individual chargers. I would like to make a charger where I can charge all my (8) lights fixtures at once without the need of plugging 8...
  9. ShortCircuitJ5

    Battery, Light sensor and a mini motor?

    First the picture, because a picture is worth a thousand words. Is this possible? If the light is OFF, then the motor stops. Low light brigthness = low motor speed. High light brigthness = high motor speed. Thanks.
  10. Younes Thabet

    what's a good power-management solutions for wearables?

    Hello all, I am intending to make a wearable device that have a GYRO, ACC sensors, monochrome display, BLE connection. the wearable will be powered with a rechargeable 50mAh (both wired and wireless charging). I have checked multiple solutions from different semiconductor manufacturers but i...
  11. Bhanu2626

    Does the MOSFET in the Schematic will work fine?

    I using the MOSFET IRFB3004PBF switching. 56.2V is a source voltage coming from the charger and 48 is the nominal voltage of the batter. switch S1 is for switching Vgs. Vgs=5 v. Rgs=10k ohms (connected to the gate terminal and battery ground). battery is 13s3p Nominal=48v Peak=54.6v Will MOSFET...
  12. T

    Battery Life Duration for Specified Voltage Drop

    I have a 8 AA batteries (12V total) that is powering a light that draws .0517A. The light no longer outputs enough light when the battery voltage drops to 8Vdc. Typically I'd calculate battery life via: 2.5Ah * 8 = 20AH. Then: 20AH/.0517A = 386 hours. Does this equation change if I want to...
  13. D

    New to wiring LEDS - what am I doing wrong?

    I like to make things and I had an ambitious idea to make a small scale Griswold house and needed to wire together 100 1.5V 100mA (AC and DC compatible) pre-wired bulbs that are typically used for hobby train use. I am a complete newbie to anything that has to do with lights and wiring, but my...
  14. M

    Help to understand the operating logic of the Bosch charger

    hi, I ask for your help to: determine, if possible, the type of transistor T5, T7 (SMD code: MK3C). help me to understand the operating role of the set T5, T7 and R23, R33 in the circuit (it's like a logical port type AND, but I do not understand how it works). help me understand why the...
  15. bmbouter

    IP5306 Charging Circuit works for 33 seconds then strangely stops

    I'm new to circuit design. I'm using an Injoinic IP5306 battery charging IC (datasheet). I also use an AMS1117-3.3 (datasheet) to drop down the 5V power it produces to 3.3V. I've attached a picture of my schematic which shows the relevant portions, the IP5306 in single-LED configuration, the...
  16. electromeow

    Relay or MOSFET for high current?

    Hi, I have to switch a high current(DC 12V@~60A approx.) for a battery-supplied circuit. But its on-status resistance should be as low as possible. Because you know the Ohm's Law, the I is going to increase up to even 100 amps sometimes, so a very small resistance creates a big difference. I...
  17. oferorgal

    Battery simulator

    Hello, I want to design a battery simulator circuit to test my board. My board connects to a single cell li-on battery, 3.8V 2400mAH and it has a wireless charger circuit with up to 400mAH charge. The battery simulator needs to provide up to 1A to the board and to be "charged" at 400mA. I've...
  18. R

    4s3p battery pack on 2 level

    hi for a diving light, i need to create a 4s3p battery pack (lithium). I can have max 2 level of battery in a delrin cylindrical. What could be the easier wiring for welding? I put all battery on the same side... but it's not mandatory... thanks
  19. R

    DC to 3-phase VFD for providing induction motor with battery power (~8kW)

    I'm building a mobile robot which is quite heavy and needs some serious HP. For this and other reasons I want to mount 4 induction motors to each wheel (for a total output of about 8kW) and power them via batteries. However, those motors need 3-phase current and I obviously can't plug them...
  20. ronit991

    Better approach for powering up sensor nodes ?

    I have a sensor node containing an MCU & radio running at 3.3 V and a sensor running at 5 V. What is the better approach for powering up the system (in terms of efficiency, stability, etc.) : 1. High Voltage Battery + Buck Converter or 2. Low Voltage Batttery +...