Quote:
Originally Posted by mort
Yes, but the devil is in the details.
The resistance of a light bulb varies with it's power consumption - so that the ratio of off to on resistance is about 15:1 Ben has some 50 watt 12 volt bulbs. The on resistance is about 3 ohms, the off resistance is about 0.2 ohms.
(Fewer light bulbs for a lower current limit.)
But as the lithium cell's voltage comes up and the charging current drops the light bulb resistance will fall (we'd like it to rise).
-mort
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I believe you sort of agree with what I said, because Ben is using a 12v source to charge a (theoritical) 12v set of batteries the lightbulb behavior is EXACTLY what I would want to happen assuming the voltage curves are matched.
So as the light bulb resistance falls the amount of the difference in voltages is also falling meaning current is still tapering, which in my mind is fine since he has a controlled voltage (battery)