Battery post melt down

[rfischba1]

Anyone have any advise on what might cause a battery post to melt down on a duce 24 volt system. Maybe a short in the battery cables? Batteries are almost new.

 

[mangus580]

dirty connections....

I had one do this...

want to know how I salvaged the battery? I milled the melted post down flat, drilled & tapped it. I then threaded one of them sidepost to toppost converters in

 

[Blythewoodjoe]

A few years ago before I installed the master switch on my deuce I used to just keep the ground post loose and I would push it down real hard onto the battery when I wanted to run the truck. One day I hit the starter and heard a nice arc. Checked the battery and there was a puddle of lead next to the ground post. I figured out where the arc came from. I always tighten the bolt on the post before I hit the starter now.

Joe Trapp

 

[WillWagner]

Only other thing, a shorted battery, but the battery usually explodes. Most likely, a loose/dirty connection at the battery. Most loose or dirty or poor connections will cause an arc or spark at the failed connection, battery cable end, frame/cab connection, starter. etc.

 

[rfischba1]

That sounds like may have been the problemn nice idea about improvising the post, mine is only half melted and still works. Its getting a little acid build up on the melted post, I've got to clean the post up.
Thanks guys.

 

[mangus580]

Mine was half melted for a while, and got progressivly worse until poof.... it was gone

fix has held for a year...

 

[DaveP]

Loose/Dirty connection.

 

[cranetruck]

A poor connection will increase the resistance, which will cause a dramatic increase in heat generation (=meltdown).
A good connection at the battery should only have a few milliohms of resistance, causing only a few tenth of a voltage drop when the start motor is running.

A side effect of a poor battery connection is the generation of a "load dump" if the batteries are not fully charged. This load dump consist of a voltage spike, which may destroy the voltage regulator. It could easily reach 100 (one hundred) volts and is another reason for using the MX-7777 transient supressor when radios are in use on your vehicle.

It's a little beyond what you asked about, but it's all realated.

 

[acetomatoco]

Poor installation and poor maintenance... "Check Batteries Daily" stencil is needed and heeded... ACE

 

[panshark]

has anyone else had luck doing Mangus's repair? I melted a top post (positive) last night. It was my replacement battery for when I melted a top-post off of an old pair of batteries... I was thinking about possibly heating up some lead in a bullet smelter, and try to pour a new post. If I got that route, I'll be wearing protective clothing, goggles, and earplugs (in case I get an explosion as a result of my efforts). I was thinking about using a 5/8" ID pipe as a mold. However, Mangus's repair sounds like a really good idea!

 

[spartan_185]

I had my m109 do the same thing about a year ago. It turns out one of the battery connectors worked itself loose and caused an arc. It melted about half the post. I happened to convince the place that I bought the battery from that it was a manufacturer defect and got a new battery out of the deal. I now check my terminals about every other drive.

 

[panshark]

no dice on returning the battery, I bought a couple of blemish batteries from Dirtbag Charlie, the only junkyard guy here in town who's guaranteed to pee his pants. Period. I got him to knock a couple bucks off by reminding him how I convinced my company to refund him his money for a repo truck that he bought and the co sold to someone else. Tells you what kinda company I work for. So unless I want to take the other battery (which is kinda big) and try to fit it into another rig, and pay another visit to Dirtbag and watch him pee himself when I give him $30 per for a pair of batteries, I'm gonna need to fix the one I've got.

If you all think I'm making up the story about this Charlie fellow, call him up and ask him "if he should retire." 208.523.6248 Don't ask him about the truck he bought but never got, you'll never get off the phone...

 

[cranetruck]

A ruined battery post is not uncommon, I have melted my fair share over the years. They can be repaired, though. Get a replacement post from NAPA, drill, tap, install replacement and continue to use your battery.

The best result, I would imagine, since I haven't done this, is to use a mold and pour a new terminal per instructions in TM 9-6140-200-14 (image below).

 

[orren]

Great idea. Now where do we get the molds?

Thank for the help,
Orren

A ruined battery post is not uncommon, I have melted my fair share over the years. They can be repaired, though. Get a replacement post from NAPA, drill, tap, install replacement and continue to use your battery.

The best result, I would imagine, since I haven't done this, is to use a mold and pour a new terminal per instructions in TM 9-6140-200-14 (image below).

 

[Mike_L]

I saw a mechanic do this once on my track in Germany. Freaked me out when he put that torch to the top. I never saw that before and thought for sure it was going to explode. Anyway, he used a what looked like a large nut with an internal diameter about the same as the post on the good battery. I don't remember the size. Then he dressed up the threads with a file to smooth it out before he put the cable back on. Never had another problem with those batteries. To this day I thought he was put some 'shadetree mechanic' fix on it but now I see it is actually in the TM. Darnedest thing I'd ever seen working on vehicles.

 

[dozer1]

Drilling and tapping it for a replacement post sounds like a good idea. I would screw that new studded post in with nolox or oxguard on the threads. At least some grease. Probably milk the remainder of the life out of the battery. I have exploded a battery in a motorcycle frame before while heat shrinking some shrink tube. Don't like flames near batteries anymore.

 

[steelandcanvas]

I would screw that new studded post in with nolox or oxguard on the threads. At least some grease...

I don't think "grease" would make a good electrical connection. Noalox or Penetrox, OK.
I have also been assigned to motorpools that poured new terminals on batteries.

 

[cranetruck]

I don't think "grease" would make a good electrical connection. Noalox or Penetrox, OK.
I have also been assigned to motorpools that poured new terminals on batteries.

The threads pull the contact together, the new post against the finished flat old surface. The threads don't have to carry any current for it to work.

 

[dozer1]

Bjorn, if you dont mind my asking. What would your take be on using a "noalox" type product on battery terminals in general ? I know its not really designed for that application, but it is conductive and grease like.

 

[rattlecan6104]

I ran with one dead battery for a while and apparently had a fairily loose terminal, It blew out the terminal and damaged the wire clamp. I figured this was just as good a time as any to get new batteries. Instead of using original equipment batteries, I bought a pair of commercial batteries with 1140 cold cranking amps each that had threaded top posts, hooked up wires with lock nuts, cranked up the engine really nice, and havent looked back.