Lead Acid battery charger

Hello everyone,
I am building a Lead acid battery charger for my project. I have a power converter that converts 110V to 12V, 5V and 3V. I am using 12V to run my project and i want to build a back-up power so I bought a Lead acid battery and now i m trying to build a charger. MY Idea is to run 12v from the power inverter and if that fails using diodes Lead acid battery will take over.

NOw i know that my Lead acid battery will produce about 12.4V so i had to bring my 12V from power converter to 13.8v so my project keeps running on that and not on battery.

so need help building charger from using 13.8V from power converter to charge a 12V battery with 7A. my input is 13.8V and i need to charger 12V lead acid battery with 7A.

Please HELP.

Thank You All

hi manojp.
there are some very recent postings regarding sealed lead acid, 'floating'
chargers. Do a forum search.
If you cannot find the postings, let us know, someone will guide you.

Regards
Ericg

Why are you converting 13.8V (which would be perfect for float charging a lead acid battery) to 12V (which won't be enough to charge a lead acid battery)?

You don't need 7 amps to charge the battery, it will be floating most of the time. I looks to me that you can just connect the 13.8 volt source to the battery. I assume that is why you chose that voltage.

Hiya, try my circuit out. Despite the fact I am having problems with it at the moment, it has been operating for 8 years or so.


https://www.electro-tech-online.com/threads/battery-charger-help-sch-included.35664/

Lead Acid Charger.

I,think the charger at this link is a good charger http://www.talkingelectronics.com/projects/BatteryCharger-12vSLA/BatteryCharger-12vSLA.html

Russlk said:

just connect the 13.8 volt source to the battery.

Click to expand...

so a 3A charger can charge a 75AH 12VDC LA battery

Hello,

How much amps are required to fully charged two 12v 150AH deep cycle lead acid batteries connected in series (24V)