Pls help

[Valentine]

Pls can someone help me with a 12v 4amp overcharger cutoff battery charger.

 

[Hero999]

https://www.electro-tech-online.com/threads/automated-battery-charger.95895/

 

[Valentine]

i posted that sometime ago, but didn't get any schematics. Pls help me out.

 

[MikeMl]

i posted that sometime ago, but didn't get any schematics. Pls help me out.

You got good advice in the original thread, especially that you have to know what kind of battery you are charging, which you never answered!

 

[Valentine]

Its a lead acid battery. I'm quite sure it's not deep seal, but not certain which other one it is. I'm sorry for not answering ur question.

 

[Hero999]

I'm assuming you mean a 12V, 4Ah SLA.

What sort of charger, fast or float?

A float charger is simple, just make an LM317 voltage regulator with an output of 13.8V and connect the battery to it. It will take a long time to charge but is simple, cheap and reliable.

A fast charger is slightly more complicated, charge to about 14.8V limiting the current to <4Ah, when the current drops below about 400mA the battery should be either disconnected or allowed to float at 13.8V.

 

[Valentine]

Ok, lets get this straight. The battery should be used to power a 40w inverter: i suppose 12v 4ah SLA will be ok. Power supply in our area is quite epileptic so i think the fast charger would be best. And should be automatic. Would you mind helping me with schematics.

 

[Hero999]

Use a 15V transformer, and a 4,700µF capacitor.
**broken link removed**
Connect it to this circuit:
**broken link removed**

Connect a 100nF capacitor aross the output and use 220R and 2k2 for R1 and R2 respectively.

 

[Valentine]

How about these

Use a 15V transformer, and a 4,700µF capacitor.
**broken link removed**
Connect it to this circuit:
**broken link removed**

Connect a 100nF capacitor aross the output and use 220R and 2k2 for R1 and R2 respectively.

those an't clear on my screen. I got two schematics, i don't know how this one cutsoff https://www.aaroncake.net/CIRCUITS/charger2-1.gif and https://www.electro-tech-online.com/attachments/powersoniccharger-jpg.16689/

 

[Hero999]

those an't clear on my screen.

What do you mean they're not clear?

Your monitor must be broken.

 

[Valentine]

Sorry, it's not actually a monitor; i use a cell phone to browse. Pls did u checkout the links. What do u think about those?

 

[Hero999]

In don't know

What do you think about those?

 

[Valentine]

Pls i seriously need some help. I'm running out of time. I'll appreciate any help offered. These are the links to the schematics https://www.aaroncake.net/CIRCUITS/charger2-1.gif and https://www.electro-tech-online.com/attachments/powersoniccharger-jpg.16689/

 

[Hero999]

When has it got to be in for?

I've helped enough, I'm not going to do it for you. I will help you more if you first help yourself.