Hello guys,
I am a beginner in electronics.
I have a new 12V,1.5 mah NiCd battery, and 12V 2A adapter.I want to make a battery charger for the same. How to make one?
I am going to use it on my line follower bot.





Moderators note: taken the essential parts from the pictures, we do not need the tablecloth.

 

Here is one using a Lm317.

http://www.next.gr/uploads/6/simple-nicd-charger-circuit-diagram.GIF

Make R2 120 ohms, R1 1.2K, R3 5 ohms, all 1/8W, this will give you a voltage of 13.2V max current of approx 140mA. Use a 15V DC supply.

I think your batteries should be 1.5Ah and 2Ah

 

Yes, you need more than 12V to charge a 12V NiCd battery.

 

Thanks for reply!!!
Using 12V, will allow me to charge battery upto 12V right? Won't it help With respect to overcharging? Or will it create any problems

 

.............. Won't it help With respect to overcharging? Or will it create any problems

Possibly
Measure the power supply voltage with no load on it and again with a load of about 1/2 amp.

 

what you think about this circuit??

 

Hello,

Without any values given, it is impossible to say.

Bertus

PS I reduced your pictures to their essentials.

 

 

R1 - 1.2 kilo ohms 1/4W
R2 - see R2 and D2 table below
R3 - 2 kilo ohms 1/4W
Q1 - TIP41C or any NPN transistor min 1A current and 3W power
Q2 - 2N2222, CS9013, or similar NPN transistor
LED1 - Red or any LED with forward voltage around 2V (see LED)
LED2 - yellow or any LED color except Red
D1 - 1N4001 or similar diode
D2 - see R2 and D2 table below
DC supply - 12V to 15V DC supply or battery

Read more at http://www.simple-electronics.com/2011/10/simple-ni-cd-charger-automatic.html#seBZzFtOBHcCE1C6.99

 

Hello,

Led 1 is important for the charging current.
Led 2 will show the end of charge, it will reduce the charge current.
The voltage table does not show a value for an 12 volts battery zener value.

Bertus

 

The imp thing is to save battery from damage. That zener value is max voltage battery can handle. For 12V, 12.56 to 13V