Typical 100W panel is 12V class, let's pick one of Renogy's. Vmp 17.9, Imp 5.72. Miady battery is 12V lifepo4, so put it at 12.8V to 14.2V. Assume the panel actually produces 100W at a given time.
MPPT, 100W in, 98% efficient conversion - may not be depends on the curves, 98W out.
PWM...