Aluminum battery cables

[murphey]

After 11 years of owning the cherokee I just discovered the cables are Al and not copper. I put a SkyTec starter on a couple years ago and haven't had much trouble starting the engine (O-360). As a rule, I don't fly when it's below 0F - the airplane is fine, I just don't like it. Overhauled the mags last summer (over 500 hours each).

I'm wondering if it's worth the agony (removing the entire left interior and other crap) to replace the cables. And yes, I've had the Bogert cables sitting on a shelf in the hangar for 4 years.

 

[Henning]

If all the connections are in good shape, just wait till the next annual when you have that all opened up anyway and install them. Although if you really don't like the Al, do it now. It's really not that big of a deal to pull the interior out.

 

[Ted]

My Aztec was 40 years old with original 40 year old aluminum battery cables when I replaced them about a year and a half ago with copper. The starters throw the props around quite nicely now, whereas before starts were more tiresome. It was definitely a worthwhile investment.

I agree with Henning. If they work, just leave them until the next annual, replace them then. I'm assuming your Cherokee is of similar vintage to my Aztec.

 

[Bob Noel]

I don't remember the difference in weight, but consider the reduction in useful load if you switch to copper.

 

[mikea]

I bought and had installed copper battery cables when I put the Sky-Tec starter in my Cherokee. I don't think we adjusted for the weight of the cables. The lighter starter did make the nose lighter. I guess what weight the cables add is more than made up by the lighter starter,

Now, I'm amazed how much I threw at the plane when I first got it. The starter are cables were the least of it. That was when I was rich.

 

[gismo]

After 11 years of owning the cherokee I just discovered the cables are Al and not copper. I put a SkyTec starter on a couple years ago and haven't had much trouble starting the engine (O-360). As a rule, I don't fly when it's below 0F - the airplane is fine, I just don't like it. Overhauled the mags last summer (over 500 hours each).

I'm wondering if it's worth the agony (removing the entire left interior and other crap) to replace the cables. And yes, I've had the Bogert cables sitting on a shelf in the hangar for 4 years.

Aluminum cables can handle the same current with the same voltage drop as copper when new (assuming they're upsized properly) but over time aluminum wires suffer from degradation over time with increased resistance from fatigue cracking/crystalization as well as corrosion where the wire meets the inevitable copper connection. If it's working now leave it till the next annual when you'll already have some of the access needed.

 

[Tom-D]

I don't remember the difference in weight, but consider the reduction in useful load if you switch to copper.

They do not add weight, the copper cables are smaller, and weigh the same but do a better job.

 

[Tom-D]

Aluminum cables can handle the same current with the same voltage drop as copper when new (assuming they're upsized properly) but over time aluminum wires suffer from degradation over time with increased resistance from fatigue cracking/crystalization as well as corrosion where the wire meets the inevitable copper connection. If it's working now leave it till the next annual when you'll already have some of the access needed.

The problem usually occurs at the connections, the swagged ends have a higher Resistance than the copper to copper terminal ends.

 

[steingar]

These days I keep my Cherokee hooked up to a cheap motorcycle battery tender. Haven't had a problem starting since.

 

[gismo]

They do not add weight, the copper cables are smaller, and weigh the same but do a better job.

WRT the wire itself, copper requires about 63% of the area as aluminum for the same resistance but same volume of aluminum equals 30% the weight of copper. So ignoring the slightly heavier insulation required for the larger diameter aluminum wire, copper wire weighs about twice what aluminum does when comparing conductors sized for the same current.

 

[sourdough44]

This is on my to-do list also, for a 74 Warrior. I think I'll have the cables ready for the annual next Fall. Just buy them sized from the company(Bogert sp?) or some other source? Thanks

 

[murphey]

This is on my to-do list also, for a 74 Warrior. I think I'll have the cables ready for the annual next Fall. Just buy them sized from the company(Bogert sp?) or some other source? Thanks

Pretty much. Bogert's come with the STC, IIRC and correctly sized for your specific airframe.