Using mppt and dc-dc chargers on a bike.

[68C]

My motorhome has a solar panel which outputs from 0 to 18volts depending on sunshine. The Maximum Power Point Tracker (MPPT) controller drops the voltage to a safe battery charge level, then converts the excess power to raise the amperage. As the sunshine varies it tries to keep the charge voltage constant while altering the amperage.  Like most battery chargers it also senses battery voltage for the relevant bulk, absorb and float requirements.  I imagine the voltage regulator fitted to our bikes does something similar however it will not raise the voltage to the commonly required 14.4volts to fully charge a battery.  I assume this is because everything else on the bike is happier at a slightly lower voltage.  The DC-DC converter takes in any DC voltage and converts it to the required DC voltage, lets say 13volts for arguments sake.  So by using an MPPT controller we can take the raw frequency and voltage wild output from the alternator, rectify it and apply it to the MPPT controller to facilitate battery charging with a sophisticated charge routine, then apply a constant smooth voltage to the DC circuits through the DC-DC converter.  I wonder if anyone else has done this, these are not that dear and can handle 20Amps  or more easily.

[emry]

Wow. Yes, modern charging technology could be applied here. But remember that the generator on the Guzzi's produces AC current, which the poor low cost reg/rec then tries to keep with in limits after rectifying for for a PB/acid battery. Which are pretty resilient to abuse overall. You could use your DC-DC solution down stream of the current reg/rec but it probably wont get you much net positive results due to the poor AC-DC component in the system.

Can a better AC-DC reg/ref be designed that could incorporate functions like you DC-DC converter? Of course. Just time and money.

[68C]

It is the charging circuit I am more interested in, being able to raise the voltage so the admittedly small battery can be properly charged.  Of course, unlike my motorhome when on electric hook-up, the bike alternator does not run for hour after hour so we perhaps need to not concern ourselves too much with ensuring we have a full multi level charge profile with protection to ensure no fluid loss/excessive gassing but would like to ensure battery does fully charge.  I am being careful not to quote any specific charge voltages here as depends on ambient temperature and cell type.  I suggested the DD-DC converter to protect the ECU and any other sensitive equipment that may be connected such as GPS, LED lighting.