LTC4020 choice

Hi, 

I'm designing power managment board with battery backup feature. It has to support 1S and 3S Li-Ion charging, and 6S lead acid chemistries. Also, wide input range from 5 - 30V is needed, this was the reason for buck-boost converter. It will be powered by solar panels on some occasions, but it also has to support 12/24V power supply input. Also I would want power path option.

I choose LTC4020, my only concern is efficiency at low light with solar panels. I'm just checking if there are some better options, or I picked a good match.

Thanks in advance :)