Battery issues
 

Hey guys, got a question. My car won't start after a few days of usage without a jump, and I'm not sure if my problem lies with the battery, alternator, or somewhere within the wires themselves.

While doing some routine maintenance, I noticed that the tray, for lack of a better word, is completely rusted out. Its so bad that the battery is literally held in place (near the driver tire) by only the battery cables. I know this can't possibly be good for the electrical, as I'm going to end up prematurely destroying the alternator, if not worse.

I thought about, and started to attempt, moving the battery to the trunk instead. I even went and bought twelve feet of battery wire. Apparently though I misjudged the distance I had to cover (never been good with eyeball measuring). So now, unless I can figure something out, I fear I am stuck here.

Its been a few years since I did any real electrical work, so my memory is a little foggy. Do I face the risk of too much voltage drop if I were to attempt a splice using the existing cable to run just the last few inches, especially given that the positive cable had been essentially suspending the battery, or would I be okay in using that, and simply connect the ground to a non painted part of the trunk? This is my work car, so while aesthetics don't matter, it MUST stay running.

Any help is greatly appreciated.