How to charge lead battery

[pinkfloyd11]

Hello I should charge load battery.

I would avoid high current charge when the battery plugged is very discharged

Is correct the schematic?

Why I drop so much voltage on LM317 configured as costant current regulator?

Thanks

[url=https://obrazki.elektroda.pl/13_1339079766.png][img]https://obrazki.elektroda.pl/13_1339079766_thumb.png[/img][/url]

 

[Tahmid]

There is a constant current flowing through the load (20Ω resistor). So, the voltage across the resistor and hence the output voltage of the LM317 must be (0.474289*20)V=9.486V [as V=IR]. Your simulation shows that this is the output voltage. As, the input voltage is 13.5V and the output must be 9.486V for the constant current through the load, the remaining voltage is dropped by the LM317 by dissipating the energy as heat.

Hope this helps.
Tahmid.

 

[Syncopator]

A lead-acid battery should be charged from a constant voltage source. To limit the maximum current a simple series resistor is quite sufficient.

 

[pinkfloyd11]

thanks Syncopator and Tahmid