battery charge

J

joshelectro

New Member

• Mar 16, 2014

• #1

hi people
will 12V 1AMP transformer charge a 4.5AH 12V battery ?

 

Ian Rogers

User Extraordinaire

Forum Supporter

Most Helpful Member

• Mar 17, 2014

• #2

Not really! To charge a battery current has to flow.... You need about 13.6v to charge a lead acid 12v battery..
Transformers typically output a higher voltage than specified on the unit....

If you hook it up.. put an ammeter between them and see which way the current is flowing... It definitely won't charge it fully....

 

crutschow

Well-Known Member

Most Helpful Member

• Mar 17, 2014

• #3

Is the "transformer" output AC or DC?

 

J

joshelectro

New Member

• Mar 17, 2014

• #4

The 12v it is ac
center taped transformer

 

k7elp60

Active Member

• Mar 17, 2014

• #5

joshelectro said:

The 12v it is ac
center taped transformer

Click to expand...

With a rectifier, filter and regulator it will charge the battery. Would you like a schematic of a charger?

 

J

joshelectro

New Member

• Mar 17, 2014

• #6

ya please it will be helpfull

 

M

MrAl

Well-Known Member

Most Helpful Member

• Mar 17, 2014

• #7

Hi,

Just to note, if you are just charging a battery you dont actually need to filter the rectified DC. As long as the AC is rectified it will charge the battery.
But you do have to pay close attention to the current and the battery DC voltage. The current can not be allowed to go over the manufacturers recommendation.

 

k7elp60

Active Member

• Mar 18, 2014

• #8

I agree with Mr AL. Sometimes it is easer to use one component that does it all than use some to limit the voltage, or current or both.
The attached circuit uses a 12v charger module specifically for 12 volt lead acid batteries. The PB137 regulates the voltage very close to 13.7 and
as a result the battery will never overcharge. Mouser lists them for a little over a dollar.