- set ctrl pin(pwm) such that current into battery is always limited to max charging current on battery spec (should this current be at 14.7 V?)
Does it mean you gonna to regulate charging current using PWM?
What is approx. max current? IRF510 isn't logic level, and at +5 V Gate could pass a few amps, have you verified with data sheet?
You aware, that smoothing out PWM (1k and 10 uF) you gonna dissipate significant amount of power on transistor?
- as voltage come towards 14.7 the current will start to drop inherintely as battery resistance rises (is this correct)
- once current is low enough light up LED to indicate charge complete
- Isn't correct, battery resistance lowers.