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Alternator relaxer - continued
The circuit is configured so that when I break, it will switch off and charge the battery at higher voltage for about a second and a half after releasing the breaks. This is so that if I do pulsed breaking to stop wheels locking for example, the breaking effect of the alternator is constant.
This timing circuit is formed by the 18K ohm resistor and 10uF capacitor at bottom. To make time longer put in a bigger capacitor or resistor, to make it shorter make the resistor or cap smaller. Preferably only change the capacitor.
I set my voltage in normal, non breaking, mode to be 13,4V. This is like a float voltage for lead acid batteries. So the battery will charge at a very, very slow rate, but stay around 90% to 100% full. The regenerative break charging will keep the battery close to full, or sometimes overcharge to help for sulfation, depending on how much it is used.
If you turn up your radio or use lights at night, the voltage won't drop below the 13,4V in my setup. So I never need to charge my battery from electricity to get it full. Of course if you have solar panels on the roof, you can make this voltage lower.
Temperature affects battery charge voltages, so if you live in very cold climate, you can make the high charge voltage higher as well as the float charge voltage. Or leave the float charge where it is.
Maybe all this information is a bit too much, but I wanted to explain it well for people who want to use it a bit differently. So build it as it is and change it from there if it doesn't work correctly for you.
I would like it if someone with a scangauge can build this and give some feedback of the mpg effect. My diesel pickup works on a fill-up and work out the consumption basis. There is no cheap way of seeing the immediate consumption.
Remember that this circuit might or might not confuse vehicles with too much computing power. Luckily my vehicle's most complex circuits is the alarm circuit. If it does confuse your vehicle, try changing the 10uF capacitor next to 15V zener diode to something bigger like 47uF. This will make the transition between the low and the high charging voltage slower.
Before I forget, all capacitors should be of value 25V and higher. If you want your high charging voltage to be more than 15V, you will need to change the 15V Zener diode to something a bit higher than what voltage you want. The Zener diode is there so that the circuit doesn't send a too high voltage into the alternator and damage it. Normally a battery shouldn't be charged much higher than 15V anyway.
Enjoy
Jan
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