This has two charging rate options 15amps and 20 amps, you need a amp-meter to see if your solar panels are able to provide 15 amps or it provides less as output from solar lot depends upon the time of the day. Description does not says as how intelligent a system is, like I would expect following
1. Operates like a ups the way it takes power from wapda and delivers it to a dedicated line while simultaneously charges the battery bank using the output from solar panel only.
2. During power outrage, provides power to the dedicated line via solar panel and batteries.
3. During night, it should detect that solar panels are not giving output so should become a plane ups, charges the batteries from taking power from wapda.
Otherwise, your batteries will remain expose to damage from remaining in discharge state. Kindly verify using amp-meter, cutoff should be adjusted to 14volts to 14.4 volts.
p.s: low c.g maybe because of above quoted reason, less charging rate as solar panel will deliver a limited current.just verify??
second kindly dont run your fridge on ups or solar panels. no ones does so as its exposed to damage because fridges consumes far more power, if i would have taht mush of power then i will spare it for all the lights and fans for my home.