Need info on the stock solar panel setup on a 2002 Signature 40

[Benjamin]

4 hours ago, waterskier_1 said:

...Note that with PWM, it just switches On/Off the input voltage to maintain the set charge voltage.  So, anything more than the charge voltage put the device overhead (typically 3 - 5 volts) is just thrown away.  That is the beauty of MPPT controllers, they can use what would have been excess voltage, and provide additional charge current...

Sort of.  In the context of whether a new controller will squeeze more power out of the existing panel, probably not.  The PWM will have a certain inefficiency from the voltage drop at full output of one or two volts.  When the battery voltage rises to the setpoint, then the PWM will have a higher voltage drop, but that's because the battery will not take more amps at that voltage, so a MPPT controller will not do any better at that point.  An MPPT gets it's efficiency by running on a higher voltage panel string, so making charging voltage at almost any light level, and keeping the panel at the Maximum Power Point longer by keeping the array voltage in the right place to get maximum watts, during the bulk phase of charging before the battery reaches the set point.  Once the voltage set point is reached BOTH a PWM and MPPT will choke back the voltage and amps applied to what the battery can absorb at that voltage.