Main cable to Starter Solenoid melting. Why?

[ThreeCW]

Originally Posted by Victor B

That's a good question. This my first ever buggy, so I have nothing to compare it to. Maybe someone else can answer the question.

I can offer my experience on a temperature check I did on my 48 volt Cushman ... which is a fairly heavy work cart. After hauling a heavy load with my cart a distance of approx. 1/2 mile at slow speed (3 to 4 mph) with a total weight including cart of about 2500 lbs, I felt the temperature of my motor, controller and all high amperage cables (2 AWG). I recall that my motor was too hot to hold my hand on for more than a few seconds, my controller was fairly warm to touch (holding for more than 5 seconds got uncomfortable) and my 2 AWG cables and all cable connections were pretty much at ambient temperature.

I understand that your have 4 gauge cable between the batteries and 2 gauge cable to the solenoid. I would think that if your 2 gauge cable to the solenoid "was warm, but not nearly hot enough to melt", that your 4 gauge cables would have been even warmer due to the higher resistance of 4 gauge cable. I am not sure what it is, but I suspect that you may have a problem if that 2 gauge cable is getting warm after a 1/2 mile. Can you tell us what sort of temperature you saw on the 4 gauge?

I suggest that you post a photo or two of your present 2 gauge cable including both ends and perhaps one of the BGW members might be able to help you troubleshoot this concern.

[Gazoo]

Maybe give us a cross section of that melted cable to see the copper. I'm new to the hobby as well but I recall seeing another post where someones cables melted. Theirs were not comprised of fine strand copper wire and instead used a much fewer a/c type copper stranding which seemingly heats up.

[Victor B]

Originally Posted by Gazoo

Maybe give us a cross section of that melted cable to see the copper. I'm new to the hobby as well but I recall seeing another post where someones cables melted. Theirs were not comprised of fine strand copper wire and instead used a much fewer a/c type copper stranding which seemingly heats up.

I bought a ready made made cable off of aamzon.com. It is made for ez-go carts. Yes, it is fine strand copper. You can look at it here.

https://amzn.to/2J4OBuE

[Victor B]

Originally Posted by ThreeCW

I can offer my experience on a temperature check I did on my 48 volt Cushman ... which is a fairly heavy work cart. After hauling a heavy load with my cart a distance of approx. 1/2 mile at slow speed (3 to 4 mph) with a total weight including cart of about 2500 lbs, I felt the temperature of my motor, controller and all high amperage cables (2 AWG). I recall that my motor was too hot to hold my hand on for more than a few seconds, my controller was fairly warm to touch (holding for more than 5 seconds got uncomfortable) and my 2 AWG cables and all cable connections were pretty much at ambient temperature.

I understand that your have 4 gauge cable between the batteries and 2 gauge cable to the solenoid. I would think that if your 2 gauge cable to the solenoid "was warm, but not nearly hot enough to melt", that your 4 gauge cables would have been even warmer due to the higher resistance of 4 gauge cable. I am not sure what it is, but I suspect that you may have a problem if that 2 gauge cable is getting warm after a 1/2 mile. Can you tell us what sort of temperature you saw on the 4 gauge?

I suggest that you post a photo or two of your present 2 gauge cable including both ends and perhaps one of the BGW members might be able to help you troubleshoot this concern.

The 4 gauge cables between the batteries never heat up. There were at ambient temperatures. Only the main leads are the ones heating up. Here are the cables I am using:

EZGO TXT 94-Up Medalist/TXT Golf Cart Battery Cable Set (4 Guage)

ABN Marine Battery Cable & Tinned Lug 18” Inch in Red, 3/8" Inch Stud, 2-Gauge – For Cars, Trucks, Boats, Golf Carts


Oh! I don't think my cart could even move with 2500lbs of weight on it. With me and my wife together on it (380lbs combined), it struggles going up any kind of hill, and we have to push it up any steep inclines. Remember, this cart was given to me (not working), so there is no telling how hard it has been used and abused. Never look a gift horse in the mouth and all that. LOL!

[Sergio]

I would guess the cables are getting "warm" near the ends and not in the middle...

Almost all stud posts on a Golf cart are 5/16" (batteries, Controller, motor and Solenoid).

Some replacement Heavy Duty Solenoids and reversing contactors may have 3/8" studs.

That cable also has "steel lugs" which are not as good as tinned copper lugs.

The oversized hole is particularly troublesome on motor posts and solenoids that have a "nut" for contact surface since there is not enough "surface area" (like a battery lead base) to compensate for the lack of surface-to-surface contact.

If you are going to keep those cables, get some 5/16" copper washers (brass would be second option) to go between the solenoid and cable lug in order to increase the contact surface.

[Victor B]

Originally Posted by Sergio

I would guess the cables are getting "warm" near the ends and not in the middle...

Almost all stud posts on a Golf cart are 5/16" (batteries, Controller, motor and Solenoid).

Some replacement Heavy Duty Solenoids and reversing contactors may have 3/8" studs.

That cable also has "steel lugs" which are not as good as tinned copper lugs.

The oversized hole is particularly troublesome on motor posts and solenoids that have a "nut" for contact surface since there is not enough "surface area" (like a battery lead base) to compensate for the lack of surface-to-surface contact.

If you are going to keep those cables, get some 5/16" copper washers (brass would be second option) to go between the solenoid and cable lug in order to increase the contact surface.

You, know I have actually noticed what you are saying and wonder about getting some copper washers. The lugs fit nicely, but the contact surface area of the nut that tightens down on the lug, is maybe 50% of the surface area of the lug.

Do you know of a source for copper washers of the apropiate size for this application?

[AZ.]

Would be nice to put a clip on amp meter to see what the draw is....

[Sergio]

If the 4ga cables are not getting warm, the 2ga cable itself is not the issue, just the resistance on the connection.

Just google '5/16" copper washer', there are lots of sources, if you have a local fastenal or grainger, they probably have it in stock.

FYI, if you do a lot of "low speed" at "high load" driving, the cables on the Motor loop are exposed to higher current than the cables between batteries.

Once You have the pedal all the way down (WOT), the current is the same in all cables.

[Victor B]

Originally Posted by Sergio

If the 4ga cables are not getting warm, the 2ga cable itself is not the issue, just the resistance on the connection.

Just google '5/16" copper washer', there are lots of sources, if you have a local fastenal or grainger, they probably have it in stock.

FYI, if you do a lot of "low speed" at "high load" driving, the cables on the Motor loop are exposed to higher current than the cables between batteries.

Once You have the pedal all the way down (WOT), the current is the same in all cables.

Is Copper better then Brass? I order most everything online because it is a 60 mile trip for me to get to a major town. I found these on amazon (I get free shipping as a prime member).

Brass Flat Washer, Plain Finish, 5/16" Screw Size, 0.34" ID, 3/4" OD, 0.065"

I also found these nuts, would they also help reduce resistance?

5/16-18 Full Finished Hex Nuts, Solid Brass, Grade 360,

[radioman]

Does the other end of the new cable get warm too? Copper washers are best.