Connecting 12v battery to inverter

Hi,

I'm wondering if I need to ground a 12v battery that I'm going to use to power a live-band set up.

I have a 12v AGM battery, going through a pure sine wave inverter. I want to power a basically full band.

There will be 3 amps, effects, phantom-powered vocal mic, etc. It's a somewhat pared-down set up but still basically a full band.

I am going to connect the battery to the inverter. But do I need to ground the battery somehow? 

Also the cables to connect the battery to inverter are much longer than I need. I've also heard I should shorten them?

Do I need any special solder to connect the terminals to the cable? 

Do I need a fuse in between battery and inverter?

I've seen people on the street and their setup seems much more simple.

I think I bought good gear- I invested in this, and wanted enough oooph to power the band. But I want to make sure I do it right, and given that it's all "greek" to me, I wanted to err on the side of having sufficient power etc.

Here is the gear I have:

https://www.batteriesplus.com/batter...j6YaAnEx8P8HAQ

Amazon.com: Power Bright APS600-12 Pure Sine Power Inverter 600 Watt continuous / 1000 watt Peak 12 Volt DC To 120 Volt AC: Car Electronics

http://www.amazon.com/Cobra-CPI-A400...22P3EWE3NBGXMQ

Thanks

Hi Andrew Scandal ,

If the the negative supply and the ground of your power supply are joined together then you can Connect the negative terminal of your battery to the ground of your power supply otherwise Don’t connect. Use thick and shorter cables for connecting the bat to power supply the cable Should be able to supply and withstand the power requirement of your ckt. It seems that the Cable showed by you will support your system.