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  1. N

    Motion triggered battery powered dimmable COB LED light

    My view on life, in any field, is not to produce more but to consume less. Everybody told me this is a very eccentric weird mentality. Perhaps they are right. Nevertheless I have to build my project to make a highly efficient, extremely low drain, motion triggered 12V battery powered dimmable...
  2. Q

    Troubleshooting an old tablet that has power supply issues

    Hi, I'm quite "new" to the world of electronics I have a CS background and I have a quite old tablet laying around that has power supply issues... it started randomly turning off so I used it with the charger plugged in for a while and now it doesn't turn on. I managed to start disassembling and...
  3. G

    Special development board

    Hello Currently the Grape-Express Mini development board is on Kickstarter. It's a microcontroller board like the Arduino Mega2560 R3, but this board includes a lot more than just Bluetooth, Wifi, and self-sufficiency. If there is interest, then look on the web page. The goal is not set high but...
  4. R

    Need help with wind turbine circuit

    Hello everyone, this is for my design project and i need help on a circuit regarding wind turbine. The turbine will be used on a fishing boat. Also, the turbine will power up a raspberry pi 3. Our only problem is hooking up the wind turbine to the raspberry pi. The load will be approx 10W. Our...
  5. J

    LED Lights and Timer all Battery Powered - HELP

    good morning, first post... I have a small project that i'm trying to accomplish and i'm am not very good at electronics, so I've come to all of you. Here's my goal; I"m trying to power (2) rolls of LED strip lights for 3 hours a day, solely by battery. The project will run in a display...
  6. A

    Can you help me with this power charger?

    I am on trip and now I am is small village where I can't buy anything soon. I need charging 4 AAA batteries. Battery have 750 mAh. I have this old charger from Germany. I have electricity 220 v. How many hours I need to charge to battery be full? Thank you in advance.
  7. J

    What voltage to apply to a 1.2V rechargeable battery?

    Hi there, I am just experimenting with a simple circuit that recharges 1.2V 3000mAh AA battery. But I have not idea what is the correct voltage to apply to the battery to recharge it. Do I need to apply 1.2 Volts? Maybe a little bit more? This circuit recharges the battery using induction, so...
  8. O

    Battery Charging

    Hi! I've been working on a project and I need it to be portable. So I have two batteries of PKCELL LP785060 it's a 3.7V 2500mAh battery. I connected the two in series which gives me a 7.4V battery. My question is, can I use the adafruit powerboost 1000C to charge these batteries connected in...
  9. J

    AAA NiMH Backup Battery Pack for 12V Automotive Use

    I have been asked to play a role in the design of a 12V backup battery pack that would be used to backup a vehicle security system and siren in exclusively AUTOMOTIVE applications. I have general electronics experience but no experience with the design of a battery backup system, and the...
  10. C

    Homemade Multi Drill

    Hi, I'm thinking of making a multi drill for wood drilling, that uses anywhere from 6 to 9 9V or 12V DC motors. These motors would be wired in parallel, with one battery source. I'd mount a drill chuck on each of the motors shafts for a drill bit. Now, I need a little bit of help from you. Do...
  11. C

    Solar Powered Electric Fence from electric fly swatter and garden lights

    Hey everyone, I'm working on a little project but circuit design isn't my area of expertise. I want to build a little electric fence to put around some potted plants and keep the squirrels away. There isn't an electrical outlet nearby, so I want to rely on solar power. I bought an electric fly...
  12. P

    Lithium Battery Low Voltage Failsafe.

    This is a project I’ve recently started working on. I’m trying to setup a LiFePo4 12V battery replacement for a normal lead acid car battery. Please note, this is NOT for an electric car, its for a normal Internal Combustion Engine Vehicle. I just want to replace the Lead Acid Battery with a...
  13. C

    Homemade Lithium ion battery bank questions

    Hello all, I'm new here. I'm seeking knowledge and advice about a Lithium ion battery bank that I made. I got these batteries from work out of a device that we replaced the batteries on. It is a somewhat proprietary battery as it is made specifically for this device and not open to the general...
  14. mading2018

    Lithium battery for a PHEV?

    Hello, I trying to find a equivalent battery model for a PHEV (plug-in-electric vehicle) and simulate the charing process in LTspice. I want the battery to have SOC=0, an empty battery from the begining, and starts to charge between the charging range of 320-380 V. I know the battery should...
  15. H

    Using Capacitors as Energy storage device - eliminating the phase differ between voltage & current

    I constantly read that capacitors provide reactive power. So how are they used instead of a battery? I mean in a battery the voltage and current are in the same phase. How is the phase change between the voltage and current in a capacitor eliminated without using an inductor, to use capacitor as...
  16. sr13579

    How to charge my 9V battery with a no load 5V output?

    I am pretty much new with this adapter thing. I bought an adapter today with a 9 V rechargable battery. I tried my multimeter between the output and found something interesting. The output voltage is 5 volts on the 9V port. But when I am connecting the battery and turning the adapter on the...
  17. S

    Victron centaur battery charger overcharging, please help diagnose and repair

    Hi there, I have a Victron Centaur battery charger, 12v 200 amp output. It's a monster! On inspection it's actually two identical 100a chargers in the same case, connected in parallel. Other than a tiny 3 wire cable whose purpose I'm not sure of, there is nothing connecting the two chargers...
  18. Vizier87

    Repairing a UPS backup power supply

    Hi guys, It's been a while. Before I actually buy a UPS backup supply, I need some advice and potentially save more than 50 dollars. I found one from a friend (APC ES 500). Naturally, it was already dead. I've hooked it up to the mains and no indicator LED or anything turned on. Dead as a...
  19. mheruian

    In-depth Battery Knowledge inquiry

    Hi, I'm new to electronics and I've been starting a project of my own which is a charger (since i though i should start first at power electronics since its all about electricity before pursuing switching electronics or automation). I had previously created a charging system (using the li-ion...
  20. Mosaic

    Desulfator Engine, Heavy duty, DIY, Overnight results.

    Hi all: I'm starting a Hackaday project to open source my proven desulfator engine. This is a pulse charge engine for batteries outside the vehicle as it delivers 250W RMS capability to the battery with up to 800A pulses...
  21. Gryphonn

    Using a 12 Volt Regulated Power Supply as a Battery Charger - Questions

    Hi folks I found this forum via a Google (is your friend0 search. I found some threads loosely related to my question, but nothing specific. Hopefully, some of you electrical/electronic aficionados may be able to assist. I have an old 'Transwest' brand Regulated Power Supply in good condition...
  22. A

    Sourcing surface mount high current connector

    Hi All I'm having a dilemna at the moment, I have designned a battery balancing circuit and need connector for this that are rated at 10A max per contact perivously I used a SAMTEC IPBT connector which met my requirement the only problem was the height with the connector and the mating half had...
  23. A

    Battery Management System Design

    Hi all I am in the process of designning a battery measurement and balancing system I was thinking of using a TI BQ76930, I am following the design guidelines found on pages 4-7 (http://www.ti.com/lit/ug/tiduar8b/tiduar8b.pdf). The main issue I am having with this design is identifiying the...
  24. Cool Name11

    Constructing a 3s li-ion battery pack with a bms?

    I want to construct a 3 s 18650 li-ion battery pack with a bms, could somebody please help me in constructing this circuit i have no idea about the bms and the connections, also please provide a link of all the product that will be used
  25. M

    Lipo Battery Suppier

    Hi I have searched the forums but cannot find the answer, does anyone know of a rechargeable Lipo battery supplier that is trustworthy as a Google search provides companies from China with little information about their reputation ? We would like the battery to be similar to the one below and...

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