I am trying to make a battery charging circuit for a small solar panel to charge up to a 8P1S Li-Po battery pack. My main issue has been finding an MPPT circuit with a low enough input voltage to turn on.
The specifications for the solar panel I'm planning to use are: ~500mA input current and 4.6V maximum power point voltage.
The battery will be a typical lithium polymer pack with a 4.2V charge voltage, 3000 mAh capacity per cell (~1C max charge rate per cell).
I've found the LT3959 SEPIC converter chip which I think will work, but it doesn't have MPPT functionality. Could I Use the LTC4000 (or LTC4000-1) in conjunction with the LT3959 to form a low voltage battery charging circuit?
I also am planning to parallel this circuits with multiple solar panels and a single battery pack, will the LTC4000 be able to handle being in parallel?
I appreciate any help. If you have any recommendations for other parts, please let me know. Thank you.
