I need help in selected the proper Power Inverter for a sump pump battery backup.
Im doing this for some elderly family members that are incapable of setting the system up.

Living in the Northeast we rarely have power failures and using the battery backup may never be needed
unless flooding occurs with the power outage. That being said, below are the conditions it will be used for,

The 120V sump pump is located outdoors at the foot of basement stairs, the doorway leading into the basement
Is at the bottom of the stairs. The concreted area where water collects is about 4 Ft X 4 Ft, with the doorway being
About6 inches above the concrete. This is where the water can enter the basement. The battery and inverted will be placed on a small table in a waterproof container at the foot of the stairs with the pump plugged directly into it.

The sump pump is a Little Giant Model 8-CIA (508157), it is 4/10 HP with 10 AMPS and 830 watts.

The battery is a Deep Cycle Marine 29HM with below rating:
Amp Hours At 20 Hour Rate = 115
Cold Crank Amps = 675
Reserve Capacity = 200 Min

Now for my question regarding the inverter. I have two models in mind, below are the specs.
Power Bright Model PW 1100-12 - 9.2 Amps 1100 Watts Continuous 2200 Peak Power
Power Bright Model PW 1500-12 - 12.5 Amps 1500 Watts Continuous 3000 Peak Power

The smaller 1100 is fine with the watts but falls short on the amperage needs 10 has 9.2
The larger 1500 exceeds the specs and is almost double the price.

My concern is that if the larger 1500 were purchased it would drain the battery much faster.
The smaller 1100 is good with wattage but short on amperage by .8 amps.

Can I get away with the smaller model? All suggestions are appreciated.