Escape 19 Battery Wiring

[Matt in SV]

This thread continues some repairs on my 2009 Escape 19. Along the way there may be advice applicable to other Escape owners. My own trailer suffered some damage during a crash suffered by the prior owner, so these issues might not apply.

Shortly after my purchase, I tested the converter and battery, and both looked okay. Since that time I have been plugged in continuously for about six weeks, so I was very surprised to see there was no charge at the battery.

As it turns out, 10AWG stranded charge wire had broken where it rounds a sharp turn near the front of the trailer. This is just in front of the passenger side dinette, where the battery is housed. I could see a little pile of verdigris corrosion, and even more when I when I broke open the wire insulation.

Personally, I think the 10awg is thin for a discharge wire. For a charge wire from a converter or alternator, it's fine because there's little concern with losing 10-15 percent of the power from those sources, but if you are boondocking or charging from solar, you'll see some significant voltage drop in a wire of this gauge that will likely affect your battery run time and, potentially, its longevity.

Another issue is the corrosion around the ring lugs. They need to be treated and/or captured between a couple of washers.

a Photo below compares the 6ga charge wire on my U-haul retrofit with the 10ga wire.

Regards,

Matt

[Matt in SV]

Here are the photos, a little out of order

1. Close up of the broken charge wire. See the green corrosion here.
2. Corrosion at the battery connection, too (ring lug)
3. Comparison of 12ga (red) charge wire in the Escape with the 6ga (black) wire in my U-haul retrofit. The 6ga stuff comes from jumper cables.
4. Charge wire routing shows where it broke as it rounds the corner. I pulled it back a few inches for clarity.

[Matt in SV]

A final thought: It may be that the wire didn't break at this tight corner. It may have actually have been the failure point where it burned out under load, such as if the electrical brakes were actuated continuously after the accident. In that event, it would be appropriate to have a fuse at the battery to guard against overload, or increase the wire size to something that can handle the continuous current to the brakes.

[Bill K]

Matt,
I don't know how the Escape is wired, but most break away switches are wired directly from the battery to the break away switch. ( all outside )

Bill K

Originally Posted by Matt in SV

A final thought: It may be that the wire didn't break at this tight corner. It may have actually have been the failure point where it burned out under load, such as if the electrical brakes were actuated continuously after the accident. In that event, it would be appropriate to have a fuse at the battery to guard against overload, or increase the wire size to something that can handle the continuous current to the brakes.

[Matt in SV]

Originally Posted by Bill K

Matt,
I don't know how the Escape is wired, but most break away switches are wired directly from the battery to the break away switch. ( all outside )

Bill K

Hi Bill,

I checked it out: There's just a single #10 wire on each of the Escape 19 battery poles. The single positive lead runs across to the driver side dinette cubby, where it's distributed to the convertor and breakaway through some fusible link/breaker screwed to the underside of the bench brace.

Electric trailer brakes draw something like 3A apiece, so even if there are four (two axles), it would be about 12amps continuous, which should be well within the rating of #10 wire. I did find a corresponding hard kink in the opposite side of the cable when I traced it out to the other side of the trailer, and there is no apparent pinch point there. Maybe somebody is deliberately shaping the wire this way to keep the bundle neat? I don't know.

Regards,

Matt

[Raz]

Hi Matt. Years ago I bought some cheap wire for a project. Some time later the project stopped working. I traced the problem to a wire that was oxidized much like yours. Being cheap it was untinned and the insulation was loosely fitting and corroded quickly.

My guess, the corner rubbed the insulation exposing the copper. The moist air in the trailer started the corrosion. As the wire corrodes its cross sectional area becomes smaller, increasing the resistance. Since heat tends to speed up most chemical reactions, I'm guessing the corrosion process is enhanced. Sooner or later the wire acts like a fuse and opens. Are there any burn marks at the site?

Two things I'm unclear on. 1)Why would you want to fuse a wire that is providing energy to brakes that should be seeing continuous current only in an emergency? 2)What kind of current is normally going through the wire that you are seeing 10-15% lose? Raz

[Matt in SV]

There's a nice colorful table I have that depicts wire selection based on voltage drop and length. Basically speaking, the power lost in the wire is (I^2 • R) where I is the current through the wire and R is its resistance, which is proportional to its length. You need to use twice the wire run because power goes out to the load and back to ground. So if the battery is ten feet from the fuse panel, which is say, 10 feet from the load, you have 40 feet of wire. Anyway the power loss increases linearly with wire length, but exponentially with current, so it isn't a case of one or the other being the factor that drives the wire size. Biggest continuous loads are typically motors in fans (like the overhead fan or the one in the furnace). Assuming you aren't trying to run a DC fridge or something.

The breakaway cable is another story. I got up front and checked out the wiring and it appears to have melted insulation along its length. I don't know exactly what the current draw is but it's continuous. So either there was a short somewhere or the wiring couldn't hold up to indefinite loading. I'll have to measure what kind of load the breaks represent.

I suppose it's possible that water got into the wire and initiated the corrosion. It's good stuff though, double insulated fire resistant wire. It might have entered at the end and migrated to a low point.

[Raz]

Hi Matt. I did the calculations and even if the battery to fuse box wire were 40 ft total you would only have a wire resistance of 0.04 ohms. I guess I don't see I squared R losses as an issue. I'd replace the wire with new 10 ga. and add some protective sheathing (the spiral stuff they sell at the auto parts store) at possible abrasion points. That said, 6 ga would certainly be more efficient. All the best, Raz

[Matt in SV]

Here's a photo of the breakaway cable outside the trailer. Something melted here. It could be external heat source or maybe the brake lead shorted to ground. Maybe that could pull enough current on an infused line to melt insulation