Battery cable extensions?

[Kevin]

I want to move my batteries aft in the engine space.
Problem: Red cables are not long enough. I need three more feet on each side. I don't want to discard the existing cables if I do not have to since they are not cheap. Can I bolt another cable on to get the length I need or can I use a post style mount to link another one on?
If it degrades the capability of the starting system by doing so let me know and I will just make new cables. I am not looking for compromising short cuts but if there is a legit way it would be nice.

[CaptPatrick]

Kevin,

Shouldn't be a problem, IF:

The add on cable is heavier than the original, (so as not to have additional resistance), and the joint/splice/junction is well insulated.

[Bob H.]

Kevin, is it a location that you could add a battery switch? Could act as convenient place to make the jump to a new cable. Another thought would be a main fuse lug. Just thinking out loud. BH

[Bruce]

Kevin,
Whats the existing cable size and current(pun intended) length?

Best way is use a tinned butt splice between the cables and solder. Then use glue heat shrink, then wrap with the appropriate color good grade electrical tape 4 or so wraps.

[Kevin]

Just going off memory I want to say 00 cable. From switches under step to battery must be about 7-8 feet currently.
I could add another switch on each side but that might cost more than making new cables.
Since I can easily get to my engine space now I will pop the hatch tomorrow and get the exact numbers and some pics.

[Raybo Marine NY]

If it fits your cables

[Rawleigh]

Good crimp or solder on lugs, a bolt and heavy heat shrink. That is how they hook up the windings inside gensets all the time.

[Kevin]

The cables are 2/0. They are about 6-8 feet long from positive battery post to the switch located in the step. From the switch the run is another 4 feetish to the starter.
While looking at things it dawned on me. Why not just move the switches from under the step to the rear of the engine space? I think I could use the same cables........maybe even shorten some of them. The starters are aft and that is where I want the batteries. The only thing I would have to re-wire is the ACR's and that is much smaller wire. The whole space may look a lot cleaner as well.

Why go to all the trouble you ask? Weight and balance. Since I achieved my goal of a 25 knot cruise I am shooting for 26 now. Likely a pipe dream but I will try.