Fast Battery Charger for Rechageable Cells/batteries




Hi guys,this a fast charger for charging rechargeable batteries like Ni-Mh or Ni-Cd,etc.This charger is also useful to charge 9v recharge able batteries upto 2500mah.The charger charges the batteries upto full in just 45 minutes to 1.5 hours.check video


1. Transformer 0-9v 500ma(recommended)or 9-0-9 500ma(use the center wire and one 9v side like bridge)

2.Diodes 1N4007 -4pcs

3.Cell holder -max 2pcs

4.Rechargeable cells/battery(Ni-Mh,Ni-Cd,etc.)

5.Any 3 Amp diode for flywheel protection from batteries -1pc

6.Capacitor 2200uf 16v(prefered) or 25v -1pc

7.wooden or cardboad piece for platform or box of our project.

8.LED any color except yellow and white -1pc

misc -wires,tape,screws,scissors,etc.

Step 2: Circuit & Concept:-

The design discussed here is very simple but powerful.Its having a 9v 500ma transformer and a bridge rectifier circuitry using diode 1N4007. Capacitor 2200uf 16v are used to filter the output of bridge rectifier and enchance its current and quality ,a green led is there to indicate that the circuit is switched on.After the 2200uf capacitor the current enhances from 500ma to 800ma approx. A 3 amp diode is used as flywheel diode after the capacitor ouput to protect the circuit from damages and voltage strike back.

Step 3: Design & Making

The transformer,the PCB,and the cell holders are all mounted on a wooden ply board piece,the circuit made on a general purpose pcb and cuted in such a way so that its compact.the charger is easy to carry and can even charge 9 volts batteries(rechargeable).check video for more info.

Step 4: Ready Project & Charging Test

The project is now ready to serve you the best ,if you want to charge rechargeable 9 volts batteris then add a battery clip to it according to the polarity.After charging two rechargeable cells(Ni-Mh ,1.2 volts 800mah) for just 45 minutes the both of their voltages were 1.3v which is higher than their rated voltage which is 1.2v,for charging and testing video click here. Congratulations! Your project is ready.

Step 5: Youtube Video

Click Here for YOUTUBE Tutorial .also please like share and subscibe,see my other videos and instructable.



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    5 Discussions


    1 year ago

    This is only a transformer and a rectifier, not a charger.

    To be a fast charger it has to detect when the battery is fully charged and switch off the charger. Other (not recommended) possibility is to make a slow over-night charger.

    One of the best sources of information how NiMH battery chargers work you can find here: "Battery charging NiMH", URL is:

    You will see there what improvements you have and/or can made.


    1 year ago

    This will just overcharge and destroy your batteries. They will start leaking and possibly even set your house on fire.
    You need to terminate the charging process when a certain current and voltage are reached.

    Please do not post dangerous designs like this online if you do not know what you're talking about.

    1 reply
    Aabhishek Sharmatttapa

    Reply 1 year ago

    I have suggested the charging time just 1.5 hours. So why this will overcharge, and I'm using this by 1 or 2months and it's serving great.


    1 year ago

    OK so what precautions have you taken to ensure each cell is not overloaded with current and that only the recommended current for each cell is delivered? . None it seems . Each of these cells you have mentioned has a different requirement or you will destroy them . If it will push into a 9 Volt cell it will need greater than 9 volts to do so so what voltage are you applying to to the 1.2V nicads , +9 volts?.

    1 reply
    Aabhishek Sharmatytower

    Reply 1 year ago

    The output of transformer is not accurately 9v, it's near there 9.62., and after the 10v capacitor the output voltage is increased to 10.57v to 11v, so of we need to charge a 9v battery its output is good for it.
    The cells are 800mah already and the I have read all the cells current/charger specifications on the back side of pack, I bought 4of them in one pack, I have already seen readymade 2to3 cell chargers from inside and repaired them, and the specifications are correct don't worry.I'm using this from a month and it's serving the best and fastest. Rest your thinking.