LM317T Voltage Regulator with Pass Transistor

A list of solar panels and chargers can be found here: astore.amazon.com MPPT vs PWM Solar charger performance / MPPT Operation / How does MPPT work / What is MPPT There is a follow-up to this video that covers some questions raised about the amps. MPPT vs PWM Solar Charger - Follow-up In this video I switch between an MPPT and PWM solar charger to show how much power (Watts) can be "lost". This is due to the voltage being pulled down to the battery voltage by the PWM charger. The MPPT controller uses / tracks the best voltage output the solar panel can provide to ensure maximum power output. In this case I have two 50 watt panels connected in parallel that can be switched between the MPPT and PWM charger. Together they are producing about 3 amps at 19.49 volts; about 58 watts (MPPT controller). When I switch to the PWM controller the voltage drops to the battery voltage being charged, 12.2 volts at 3.3 amps; about 40 watts. A loss of 18 Watts!! That means a 31% gain in power using an MPPT controller. The MPPT still provides the battery with about 12-14 volts required for charging but with more amps. The gains will not always be that big; as the battery charge voltage gets higher, the gains are less. The MPPT will continually track the optimum voltage; as light and temperature change at the solar panel, so will the Maximum Power Point. Here is an excellent link to a DIY project and further MPPT explanation: www.timnolan.com



http://www.youtube.com/watch?v=QpL4RR0_QyM&hl=en