Hi there, we have designed two different battery charger boards with two different ICs of your collection, the LTC4162-L and the LTC4015, in order to compare the performance results according to our application (solar panel supply) . The two boards variants work quite well but we still have something that we are not understanding well in the datasheet so we wonder if you could answer us.
We designed our system such as represented below (datasheet pg 48) with VOUT fed by VIN with priority.
We have also seen that we could design it such as below (datasheet pg 49) with VOUT fed by VBAT with priority.
In the datasheet page 17, the following explanation is written
"Note that, due to the Power Path topology, current can flow from the input to the system load without being controlled by the LTC4162's switching charger. Therefore, the MPPT algorithm does not have full authority to track and find the maximum power point under all conditions. To obtain complete Maximum Power Point operation, it may be necessary to forgo the Power Path feature of the LTC4162 and connect the system load directly to the battery pack. In this configuration, the LTC4162 has full authority to track the maximum power point of the solar panel."
With that, should we understand that for a Solar Panel input (this is the case in our application) it is better to connect the system load directly to the battery like the second configuration represented above. Nevertheless, we find more often the first configuration in designs, and we might think that it is better to pass the power supply from the solar panel with priority.
Furthermore, it is not explained the same way for the LTC4015 and the MPPT seems to work fine even in configuration one whereas the design is very similar so we also wonder what is the difference if there is one ?
Thank you in advance for your answer,
Best regards,
Antoine Brune
