Hi! I'm new in this forum, and my english is not the best, but I will try to explain myself.
I'm charging Lead-Acid batteries with a transformer, and a bridge rectifier. If there was no battery, the signal will be a pulsating signal, but because the battery has a internal resistance, and ESR, it's quite flatted ( if it's looked in an oscilloscope, you see a DC voltage, with the upper part of the pulsating signal wich is greater than the battery voltage ). Currently, I have a voltage divider, with some 0.1% tolerance resistors. Is there a better way to do this? In the code, the ADC input is filtered with an equivalent of a RC low pass filter ( Input signal 50hz ), and then with an average code. Again, is there a better way to make this? Finally, I have to detect when the battery reaches a setpoint voltage, this is easy, but I also have to detect when the battery is disconnected, may seem simple, but when the battery is disconnected, the transformer has no load, and the measured voltage, goes up to the maximum of the bridge rectifier output. I was thinking that a zero-cross detector can be used, so when the battery is disconnected, the signal it will probably go less than 1V, because it has no DC component anymore. Will this work? Is there a more efficient way to do it? Thanks.
