12v battery charger transformer

[abdoalghareeb]

I want to build transformer to charge 12v/100AH acid battery
The primary voltage is 220 VAC.
I need three stage on secondary , so what is the best voltage of each stage?

 

[Audioguru]

You DO NOT charge a battery from a transformer because a transformer output is AC and a battery is charged with DC.
The transformer output needs to be rectified into DC and you can use a DC circuit to provide the DC voltage stages you want. You also must limit the DC current.

 

[abdoalghareeb]

I know that.
I will use rectifier.
But my question is about AC outputs.these values help to calculate Number of Primary Windings.

 

[Audioguru]

Why do you want to buy or order a custom made transformer that cannot easily be changed and have taps on it that cannot easily be switched with simple transistors?
Since you want to change the DC voltages then why don't you use a simple transistor circuit to switch DC voltages?

 

[abdoalghareeb]

I will not buy or order any transformer, I will build it by myself .
I don't need transistor circuit to switch DC voltages , because this project is a part of my whole project, so I need this design .
So this is what I need : AC voltage of three stage on secondary.

 

[Audioguru]

Where will you find core laminations and wire for your transformer?
How will you switch the secondaries to feed the rectifier?
How will you limit the charging current?

 

[D.A.(Tony)Stewart]

easiest way is find a scrap microwave oven and strip the secondary and wrap your own turns ratio for 12Vac out and then rectify and regulate with a buck regulator for CC then CV then float levels.

 

[abdoalghareeb]

I have every thing
Why you don't want answer me?
just I need the three values of secondary transformer .

 

[ALERTLINKS]

I would suggest 11V, 12.5V, 13.5V.
Charge with 13.5V tap when battery voltage is above 12.5V, this is bulk charge. This will charge battery to 80%.
If initially battery is empty and its voltage is very low, then start with 11V tap.
When It reaches 14V, switch to 12.5 tap. When battery voltage reaches 14.2V, the remaining 20% is charged.
Now switch to 11V tap. It will provide float charge .It will keep battery in charged state.
Your transformer is small and will not provide too much current. You will not need to limit charging current. 10A charging current is safe.