Lead acid batteries are not set up for continuous current charging, although they will tolerate a low current... how low? Don't know, because their makers specify a charge VOLTAGE, not current. That's why you need a constant voltage (current limited) charger. In systems where you want fast recovery of battery charge (like a car) the typical set voltage for the charger is 14V. For float charge where you just want to maintain charge long term, use a lower voltage. I run about 13.2V on mine.Just out of interest, is the "at least 5A" strictly necessary for some reason, or will it just ensure that the battery is charged to a reasonable level before the natural end of your life?
I was told before that 1/10 of the battery's capacity is usually a suitable current to trickle-charge at (though that may specifically apply to NiMH batteries, which is what I was using, I don't know), but that the current could be reduced, it'd just cause slower charging.
Is there a minimum current for charging a car battery? Other than the leakage current of the battery of course
Some kind of current limit is needed to make sure the battery doesn't get cooked while charging. I suppose s eries resistor is a brute force way, I usually build the current limiting in.What about an upper current limit for charging? Should a resistor be used in series to prevent too much current with a car battery?
you hit the nail on the head ! and thats just my opinion so don't quote me on your insurance when the house burnt down !Just out of interest, is the "at least 5A" strictly necessary for some reason, or will it just ensure that the battery is charged to a reasonable level before the natural end of your life?