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1.2V batery charger

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macobt

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J need simple schematic batery charger who will charge just one single cell(1.2V) my batery is 3500mAh.
Best regards MacoBT
 
The safest method I can see is to attach solar cell leads to the corresponding terminals. The battery can charge during the day by a window.
 
I have double glass sealed windows. They block about half of solar energy that goes to my solar panel when it is indoors.
Winter also ruins the amount of solar energy to the solar panel.
 
J need schematic to build electronic batery charger for my single 1.2V batery 3500mAh,J don want to charge with solar panels.
Best regards
 
Wire an LM317 providing output voltage of 3V. Attach a series resistor and a 1N4007 diode(.8V drop) for current limit and polarity protection.

500mA transformer can be used without any current limiting resistor for charge time of around 8Hours.

Output voltage and design calculator:LM317 Calculator
 
Wire an LM317 providing output voltage of 3V. Attach a series resistor and a 1N4007 diode(.8V drop) for current limit and polarity protection.

500mA transformer can be used without any current limiting resistor for charge time of around 8Hours.

Output voltage and design calculator:LM317 Calculator
The LM317 Calculator is wrong like most LM317 circuits on the internet. R1 is 240 ohms for the more expensive LM117. It is supposed to be 120 ohms for the LM317.

A Ni-MH battery is charged with current, not voltage. Set the LM317 with a single resistor as a current regulator at 350mA. Then if the battery was partially charged it will be over-charged if you just time the charge.

A battery charger IC detects when the battery is fully charged then stops the charging to prevent over-charging.
 
The batery is NIMH 3500mAh and I want to charge it with more amps,This batery I use for white led lamp who works on 1.2Volts
Regards MacoBT
 
A Ni-MH battery cell gets hot and has a high internal pressure when its over-charging current is high. Then a battery charger IC must be used.
 
The LM317 Calculator is wrong like most LM317 circuits on the internet. R1 is 240 ohms for the more expensive LM117. It is supposed to be 120 ohms for the LM317.

A Ni-MH battery is charged with current, not voltage. Set the LM317 with a single resistor as a current regulator at 350mA. Then if the battery was partially charged it will be over-charged if you just time the charge.

A battery charger IC detects when the battery is fully charged then stops the charging to prevent over-charging.
Wrong!
The calculator is absolutely right. Here I'm attaching the 12V battery charger application circuit from the datasheet(page21) from National
https://www.electro-tech-online.com/custompdfs/2009/01/LM117.pdf

All rechargeable batteries are charged with current.
LM317 set at 3v-diode drop(.8V)=2.2V ideal voltage and 500mA is sufficient for charging for around 8hours.
 

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I dont know very much of lectronics and ic,s,please post the right wireing and components how to build this charger for 1.2V batery
regards macobt
 
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