How to recharge a lead battery in UPS mode

Hello, 

I would like to recharge a lead battery (6V - 4500mAh) by using two different sources : a solar pannel and/or a micro USB input. The device needs to run in UPS mode (uninterruptible power supply). Do you know if ST proposes some IC that could fit my needs ? I wanted to use the BQ24450 from TI but it seems to not fit exactly what i want ...

Best regards,

Aurélien