I just recently got a 1200 watt power inverter as a temporary backup for my 1/3 horsepower sump pump. The sump pump is rated 8 amps at 105 volts so I believe the max power it uses is 960 watts. I used a kill-a-watt meter on it and found that when it is running it is using on average 580 watts although I'm sure its much more when it is starting momentarily.
I was wondering, would I be able to use a pair of jumper cables to connect the power inverter to my deep cycle marine battery? I mistakenly believed that this power inverter would come with a pair of cables but it did not.
Edit: Also, I see that there is a voltage and overload protection built into this power inverter so I was wondering would I still need another fuse or would that not be necessary since the sump pump will be the only thing connected to this inverter and it would only be used temporarily in the case that I lose power.
Best Answer
You shall want to determine the quality of your jumper cables. Inexpensive jumper cables are going to be constructed poorly at the crimps and will certainly have smaller gauge wire than a more expensive, higher quality set.
Disregarding conversion loss internal to the inverter and using simple numbers, you could say that the inverter will draw 80 amperes at 12 volts to provide the 960 watts you specify. Even if those numbers are inaccurate, it's reasonable to believe that they will serve the purpose of this calculation.
A quick check with The Google shows that starting an automobile will draw 250 amperes and higher, depending on temperature and condition of the vehicle. This gives you a factor of 3 or better when considering if the cables will tolerate such current loads.
More information about jumper cables can be found on a sister site: https://mechanics.stackexchange.com/questions/10985/how-do-i-determine-what-type-of-jumper-cable-i-should-carry
You would want to ensure you have a solid grip on both ends of the cable and watch them carefully for signs of heating. Testing the temperature of the connections with an IR non-contact thermometer, an IR camera accessory to your phone or even your hands on an insulated section will give you an indication of pending doom (or not.)
If your battery is flooded lead acid, eye protection and other suitable precautions are encouraged. Batteries explode when hydrogen gas is generated during charging, but not when discharging, reducing the danger for your project.