[Moved] comparator controlled battery charger

[babatundeawe]

here is a battery charging circuit i designed.

its working ok. i am yet to implement the pcb. but i will be using it for a more higher charging current.

enjoy it.

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to everyone who wish to modify or improve on it please do and let us all benefit. if anyone finds any fault criticism you are most welcome.
thanks

 

[babatundeawe]

can be used to charge gel and lead acid battery type.

when you connect the charger to the battery. if the battery voltage is low the fets are turned on. then battery is charged through the fet. when the battery voltage gets 12v volts the yellow led lights on and when the battery voltage gets to 14.5v - 15v the green led lights to indicate the battery is fully charged this action turns of the fets.

if the battery voltage drops below 14.5v the green led lights off but the fets are not turned until the battery voltage gets to 12v or below (depending what lower limit u wish to set) the yellow led turns off the mosfets are turned on again and charging resume.

i have included current limiting in the drawing but i had not implemented it yet.

modification and criticism are welcome to make it better.

thanks
thats just my idea of

- - - Updated - - -

can be used to charge gel and lead acid battery type.

when you connect the charger to the battery. if the battery voltage is low the fets are turned on. then battery is charged through the fet. when the battery voltage gets 12v volts the yellow led lights on and when the battery voltage gets to 14.5v - 15v the green led lights to indicate the battery is fully charged this action turns of the fets.

if the battery voltage drops below 14.5v the green led lights off but the fets are not turned until the battery voltage gets to 12v or below (depending what lower limit u wish to set) the yellow led turns off the mosfets are turned on again and charging resume.

i have included current limiting in the drawing but i had not implemented it yet.

modification and criticism are welcome to make it better.

thanks
thats just my idea of

 

[BradtheRad]

Your charger sounds as though it is efficient and effective.
Unfortunately your circuit files are from a different simulator than the one I use. I cannot see your schematic.

I wonder if your charger circuit is similar to one I made? It also uses a comparator, or an op amp:



The green led comes on when the battery reaches 14.4V. Charging stops, while the battery settles.
When it drops to 13.4V, charging resumes until the battery is back up to 14.4V.

It's an easy way to achieve a float charge, with minimal resistance intervening.

Your description sounds similar.

 

[babatundeawe]

hi brad,

here is my circuit in pdf its a little different fro yours. it employs two comparator and a resistor transistor logic nand to control the float charging.

 

[BradtheRad]

Yes, I can see that your concept of operation is more sophisticated than mine.

We both use zener-resistor pairs to create a reference volt level.
And potentiometers to set the levels for charging to stop and start.

 

[babatundeawe]

thanks brad.

but i still think that some improvement can be made to it. actually i am trying to replace the two comparator with a microcontroller and drive the fets with PWM. i hope to include the three mode of charging.