How to design a smps based battery charger?

[--BawA--]

Hii .
I want to design smps based battery charger, that can charge the battery at constant current 1amp (adjustable) with 14.1volts(adjustable) and after full charge it gives the constant voltage 13.6volts to the battery...
My battery specifications is
12v 7.2ah sla battery

So how to proceed?

 

[tpetar]

Re: smps based battery charger

Switching charger for car batteries, sealed lead-acid, VRLA batteries and gel batteries
**broken link removed**

**broken link removed**

Target voltage can be adjusted by trimmer or pot P1 (can be set in the range of about 12 - 16V). Adjust with the voltmeter connected to the output without battery connected. Voltmeter can also be built into the charger.

The current is regulated indirectly by the shunt R2 on the primary side. This simpler version is sufficient, because the current setting is not as critical as voltage setting. With values in the diagram the charging current is of about 3.5 A. Charging current can be changed by changing R2 (lower resistance - higher current and vice versa).


You can adjust this to your needs, or maybe to include even one small uC from 12F serie to monitor voltage of battery and regulate voltage of charger.

Check battery charging current in datasheet, maybe should be 0,7A not 1A.

:wink:

 

[--BawA--]

Re: smps based battery charger

Hi tpetar
Can u explain the working?
Is it possible through sg3525?

 

[tpetar]

Re: smps based battery charger

Daniel gives a massive and good explanation on his web page, read material. I suggest to see other Daniel projects on that Web site, because you are interested with SMPS.

 

[--BawA--]

Re: smps based battery charger

I hve made a dc dc converter with sg3525 .12 v to330 v so I m quite familiar with sg3525 , so plz tell me the circuit that uses sg3525..?

 

[tpetar]

Re: smps based battery charger

I didnt try to replace UC3842 with SG3525, but you can check and look datasheets for differences and capabilities.

https://www.onsemi.com/pub_link/Collateral/SG3525A-D.PDF

https://www.google.com/url?sa=t&rct...HlC6SYS2YYZg9gG53_hLg&bvm=bv.1355534169,d.Yms

Sometimes lots of things can be done. For sure circuit should be changed. You can try experimenting and try to do this, why not.

 

[amjadali56]

Re: smps based battery charger

how about this one ?????? hummm...........

 

[tpetar]

Re: smps based battery charger

how about this one ?????? hummm...........

Is there circuit ?

 

[Andrew Lebon]

Re: smps based battery charger

Hi Tpetar
greetings sir please can you give some links of electronic diy smps sites of your country or some smps russian sites i am a newbe to electronics i would like to gain some knowledge from these sites
please can you help me
warm regards
andrew lebon

 

[tpetar]

Re: smps based battery charger

Hi Tpetar
greetings sir please can you give some links of electronic diy smps sites of your country or some smps russian sites i am a newbe to electronics i would like to gain some knowledge from these sites
please can you help me
warm regards
andrew lebon

Hi Andrew,

I already give link above.

On Daniel web site you can find lots of useful things, and SMPS of course, check link :

**broken link removed**

http://danyk.cz/

:wink:

 

[amjadali56]

Re: smps based battery charger

It is not enough! Why do you need any circuit? its all there.

 

[naseerak]

Re: smps based battery charger

AoA Dear Amjad we don,t have ETD29 here in regular quantity so please give some alternative Transformer, also tell us that being a Flyback transformer is any GAP is necessary for blocking saturation.

 

[amjadali56]

Re: smps based battery charger

AoA Dear Amjad we don,t have ETD29 here in regular quantity so please give some alternative Transformer, also tell us that being a Flyback transformer is any GAP is necessary for blocking saturation.

Sorry for late Reply.... "Siemens ETD29/30 is very common in Pakistan" or you can fun with an Old PC Power Supply. no GAP is required.

 

[naseerak]

But it is not possible to draw such current from such a small ferrite.

 

[amjadali56]

But it is not possible to draw such current from such a small ferrite.

i don't understand...... :???: "ETD29/N87 Epcos" (Rated Transformer power @ 95W) can't charge a 12v 7.2Ah Battery ???:sad:


you can use: "E40 @ 230W"
"ER35 @270W"
"ETD39 @300W"
"R36.0 @310W"
an old useless PC power supply transformer will also go around 250W to 350W.

 

[hamid159]

if wanna make battery charger using sg3525 ,i'll prefer gate transformer...recently i've made 12v battery charger using this technique and is working well.

 

[amjadali56]

if wanna make battery charger using sg3525 ,i'll prefer gate transformer...recently i've made 12v battery charger using this technique and is working well.

how good is your charger? I mean current & voltage regulation, float trickle charging???

 

[hamid159]

it goes to about 1V greater battery level.Means if battery voltage is 10V it charges the battery at 11V at relative high current.By the passage of time voltage increases while current decreases.

 

[amjadali56]

can you share schematic or pcb?

 

[Gapoo]

Dear Amjad Ali,

Can you share schematic of this charger ?

Thank You.
Regards,
Gapoo