Dear sir,
I had bought tripp lite inverter 2000 watt and 2 battery of 120 amp(120*2=240 amp) , every thing is working fine unless the usage time and charge time

Charge time take about 7 hours to fully charged with inverter current of 15 Amp per hour, this sound strange for me as it should take 16 hours not 7 hours(240÷15=16) why it take less?

Usage time for only samsung refrigeditor of rated 150 watt give me only 3.5 hours, is this normal?

Could you please assist me at both issues, is there any wrong as i use voltmeter to test my both battery and it give me these reads:
14.7v at last stage of charge starting from12v
Then decreased to 13.7v when it is fully charged

Please help