starter battery died - positive terminal arc

[REF]

Those Slee terminals look pretty sweet, they’re 40 minutes down the road from me, been in a few times for some other recovery gear, they specialize in building out Toyota/Lexus rigs.
Those X2 found at batteries plus are supposed to be top notch, I haven’t splurged on those yet, opting instead for the Duracell branded AGM I referenced above.

[moorefc]

Looks like a poor connection, causing high current arcing (as described earlier). This fits the small area terminal melting (>600deg F) scenario.

After looking at the thread, saw this on amaz and they show a competitors version in a side image...zinc alloy? Perhaps remove and examine?

https://www.amazon.com/Military-Batt...0&sr=8-16&th=1


Better solution would be to get a lead military style terminal clamp.....Aluminum or other alloys are not quite as good with high current conductivity and the dissimilar metals issue as the battery terminal is lead....

[Mr.Anderson]

To follow up on this thread, I think the result was actually related to / caused by a failed alternator.

After getting a new battery installed on the van I was keeping a close eye on the dash voltage indicator and things seemed normal for a few days, then one evening driving home I noticed the battery voltage was low. I had a spare alternator with me so I installed it the next day and that seems to have corrected the issue.

What's peculiar is that the alternator must have been intermittently acting up and failing for a while. Backstory on this was that september of '22 my dash battery light started coming on and off randomly, I checked the voltage when the engine was on and off and everything seemed normal for the alternator charging the battery (e.g. ~14.3V while charging ~12.5V while engine off). But the battery light would intermittently flicker on and off. I figured it was a loose wire or something on the dash display so I didn't put too much worry in it since the starter voltage was behaving.

Needless to say, after the new alternator install was finished, no battery light on the dash so I guess the thing just slow burned for another 13 months before kicking the can. I've had other car's alternators go out in the past and it was always on or off: they either worked fine or died, no in-between where they kind of worked but intermittently.

I do have an isolator switch that connects the starter and house battery when the engine is running so the house battery can be charged while driving as well and I'm wondering if that played a role in the intermittent behavior: for instance if the alternator crapped out for a several seconds or minutes the house battery was supplementing the starter so no voltage drop would really be observed on the dash.

There still may be accessories (stereo & alarm) that slow draw on the starter but I think the bulk of the issue was related to that alternator.

I'll update this thread if I need a 4th battery from autozone in the course of 3 years. Least they've been honoring the warranty.

[N147JK]

Originally Posted by Mr.Anderson

What's peculiar is that the alternator must have been intermittently acting up and failing for a while.

It can happen. I had an alternator go intermittent on me. The way it looked I thought it was loose battery connections. Two weeks later it failed 300 miles from home. We missed an important family event and I felt like a complete idiot! I now carry a spare alternator and a spare belt in the van.

[Mr.Anderson]

Oh That's a good point I should mention:

When the battery dash light first came on, I suspected the alternator so I bought an OEM part from the dealer and kept it in my van in case it did actually fail. I thought I was prepared and had everything in the van I needed for a field repair of the alternator and I did except for one crucial thing, which I didn't even have in my d4mn garage: a 15/16" socket. Maybe a 24mm socket would have fit as well, but my neighbor had a 15/16" socket that fit it fine, a 23mm socket will not fit.

This is required to remove the pully flywheel nut on the old alternator and put on the new one because the OEM alternator didn't come with it. I'm not sure if aftermarket alternators come with that nut or not but the EOM ford didn't.

Other than needing that one tool the job is super easy and only takes about an hour to complete. It is also super handy to have a friend pull on the belt tensioner while re-installing the belt, but if alone in the backcountry you would probably figure out a way to hold it in place.

Pro tip - don't fuss with removing the wire connections until the alternator is unbolted from the engine, there's enough length on the wires that you can easily rotate the alternator to access the wire harness / connection clip comfortably. I was watching a youtube video where the guy was fighting hard to blindly unclip the wire harness with a pick which looked like a PITA.

[Orv]

Originally Posted by N147JK

It can happen. I had an alternator go intermittent on me. The way it looked I thought it was loose battery connections. Two weeks later it failed 300 miles from home. We missed an important family event and I felt like a complete idiot! I now carry a spare alternator and a spare belt in the van.

This can happen when the brushes wear out and no longer make consistent contact with the slip rings. The really insidious thing is if you only lose one phase, the alternator will still kinda-sorta charge but at a lower current and only at high RPM, and it may not turn on the battery light.