12V 65ah SLA battery Charger design

[--BawA--]

Hi , i want to design a CCCV charger for my 12v , 65ah battery , i don't want to use any microcontroller , i have a transformer which is 14V , 10 ampere output rating . i want to use that transformer for battery charging. so my question is how to design the circuit for CCCV charging mode.
i have already designed a battery charger for 12v 7ah battery using lm317. But this time its a big battery of 12v 65ah .

Any help will be highly appreciated.

 

[BradtheRad]

Your 14 VAC transformer puts out 19V peaks. This is sufficient amplitude to provide bursts of current to a 12V battery.

This simulation shows a charging session (theoretical). Battery voltage starts at 10V.



Time has been compressed, to show what the charging waveform looks like. The scope trace shows that current is reduced automatically. This resembles a built-in taper charge.

The normal rule is to stop charging when the battery reaches 14.4 V. If the transformer put out less amplitude, then you might find that charging would stop automatically.

If you wish to make it a complete project, then more components are needed, such as a switching device (relay, mosfet, transistor), and a control network (op amp. comparator).

 

[--BawA--]

I want this charger to incorporate three stages , bulk charging , absorption charging and float charging. So how to implement this . i dont want to use only constant voltage charging. It should be Constant current too.

 

[deepeshmishra]

You have to go for microcontroller based intelligent charging. It can read battery voltage and current,
according to stages can be programmed.