For example the "MotoMaster 500A Booster Pack" has a rating of 14Ah at 12v

Accounting for the change in voltage (12v on the battery to the appliance pulling 110v)

110v / 12v = 9.16
14Ah / (110v/12v) = 14Ah / 9.16 = 1.53 Ah
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Is this the correct "amp-hour" rating for the 12v battery at 110v?

P=VI
I = 130w / 110v = 1.2 A

1.53 Ah / 1.2A = 1.25h
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does this mean I could safely and confidently power said 130w AC appliance of the 12v 14Ah battery for say..... 30-35 minutes without worrying about the voltage on the battery being too low to support the device

is there anything else I should be concerned about? is this safe? is this safe for the electrical device?

would having a computer surge protector between the appliance and the battery make this safer for the appliance?
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Thanks for you for reading and thank you even more if you respond!