How-to replace battery cables on MK motor?

I sure would appreciate some advice on how to replace an MK motor’s battery cables from inside the controls housing to the battery. Problem is that my MK 40# Riptide came with only 5ft cables and for my 14ft canoe I need about 9ft. For context, my first splicing method turned out to be a dumb idea… I bolted two terminals wrapped with electrical tape but those joints now heat-up so much that it is very uncomfortable to the touch… Now that I’ve discovered the problem of course I could instead solder the joints, but I’m looking for something much better.
Question – Where can I buy a wiring assembly to solve my problem (wire 8 ga or preferably 6 ga)? Please see further details below – Thanks.
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PS - Details –
1- Having contacted MK support… “…we do not offer a longer wire, because if the wire is not long enough, a heavier gauge wire would have to be used on the extension to ensure that power is delivered to the motor efficiently. We would recommend 8 gauge wire be used on the extension. Use the plug set to attach the 8 ga. wire extension to the 10 ga. wire that comes out of the motor.” (Full speed amp-draw is 42A, thus 10 ga wire sure seems quite skimpy to me… but that is what comes with a 42A MK motor…)

2- MK’s connection method inside the motor’s control housing is a “quick disconnect connector" (female - about ¼ inch wide) which on the Internet seems rated for 10-14 wire ga).

3- MK's recommendtions for an added extension length of up-to 5ft is 10 ga wire.... (Geez, why bother splicing or using marine plugs... Why not simply replace the entire battery wiring set with at least #8 ga or, better yet #6 wire ga? )

4- Comment - On power boats recharging the trolling motor battery is no problem... But on a canoe the making sure one has enough power to get back (w/safety margin) is a big deal! (Doing the math on voltage drop with 42A on 9-10ft of cables is quite revealing...)

http://www.grainger.com/category/split-bolt-connectors/wire-connectors/electrical/ecatalog/N-8i3 i have used these....i would splice 8 gauge into the 10 gauge and try it...make sure to buy the copper ones and use battery post grease or spray ...

ideally replacing he whole cable with 8 gauge would be the way to go but you are going to run into fitting 8 gauge into a connector designed for 10 gauge...

10 gauge is designed for 30 amps but there is a big safety factor in the numbers on wire...your problem is where you feel the heat..you have a bad connection ...

you should be running a deep cycle battery.....they are designed to run down and recharge....it still decreases the life span but they can stand many more charges than an ''ignition'' battery...

papyson said:

http://www.grainger.com/category/split-bolt-connectors/wire-connectors/electrical/ecatalog/N-8i3 i have used these....i would splice 8 gauge into the 10 gauge and try it...make sure to buy the copper ones and use battery post grease or spray ...
ideally replacing he whole cable with 8 gauge would be the way to go but you are going to run into fitting 8 gauge into a connector designed for 10 gauge...
10 gauge is designed for 30 amps but there is a big safety factor in the numbers on wire...your problem is where you feel the heat..you have a bad connection ...

Click to expand...

Papyson thanks for your helpful comments. Indeed the .250" post quick-disconnect connectors used inside the MK motor housing only go to 10 gauge wire. After much fiddling I ended replacing the whole cable (9ft) with gauge 8 and cutting off the 6-or-7 strands that would not fit into the female connector. (At first I attempted soldering those strands to the outside of the connector, but that required using a torch and as I feared it annealed the connector and resulted in having no grip to the male post.) Also thanks for mentioning the battery post... I had been using ring terminals secured with wing nuts and I'm now replacing them with post terminals, incl brush-cleaning and spray. Certainly the worst problem was the bad connection I had made in extending the motor's 5ft gauge 10 wires with 4ft of gauge 8. Making the whole cable gauge 8 additionally saves a 0.2 voltage drop at 42 amps. I look forward to seeing what kind of speed increase I can get on my 2-person 14 ft canoe,

PS- Yes I am using a deep-cycle battery... A new Pro-27M from Interstate, with RC (reserve charge) of 180 (minutes at 25 amp draw)... Largest capacity I could find without going to extra weight of a Group 29 battery.