Melted Battery Terminals

[dropstharockalot]

Battery_Terminal_Melt by bignookoo, on Flickr

Sorry for the poor pic.  Both terminals look like this. Brand new battery, purchased two months ago from local dealership.  Trickle-charged as per instructions until placed in bike, only run five times since install (bike was apart during carb rebuild since battery purchase).  I had experienced a couple difficult starts (kinda reluctant to fire), but always got it going after three or four attempts - I attributed this to the recent carb re-build.

Story-
I rolled the bike out last night to head out and expereinced difficulty starting up.  The dash, brake light, and headlight lit, and flickered while the bike was turning over.  It took three or four presses on the starter button before it started to sound like it was firing, and then didn't want to catch.  Then, after almost firing, the dash and lights went dark.  There was no response when I thumbed the starter at all.  I turned the ignition off, removed the seat, and looked for smoke â€" nothing.  I let it sit overnight and came back to it today.

Same thing this morning â€" turning the key to “on' didn't light up the dash or head/tail lights. This time, I flipped up the tank and sniffed â€" there was a slight burnt smell, so I went looking for cooked wires.  I found some heat damage / melt on the rubber boot covering my positive battery terminal, so I slid off both the + and â€" terminal covers.  I then turned the key to “on”, and the dash and driving lights came back (whoo-hoo!).  At this point, I thumbed the starter â€" the bike made a half-hearted attempt to crank, and I heard sparking.  I noticed small sparks jumping around by my positive battery terminal.  I removed the screw holding the positive connection on, and discovered that the battery terminal was melted clear in half.  Ditto for the negative side.

If anyone can help me figure out what's causing this, I'd be very appreciative.

BTW, recent work:
Carb Rebuild (removed all typical necessary parts to get to carbs â€" coils, fuses, etc… fairly confident that everything went back where it was supposed to, but I could be wrong).
Installed MotoDynamics Integrated LED taillight.  All connections appear to be correct, tight, and wrapped.  i've read a few posts about quirks in electricals after the install of this taillight, but nothing about melting battery terminals...
Bike is a '96 M900 w/ 22K mi.  Dyna Coils are the only electrical system mod that I'm aware of.  Battery is a Yuasa YB 16AL-A2.


Thanks in advance!

[ducpainter]

That can only happen from high resistance which typically happens from a bad connection, or a bad starter.

Check all the connections in the starter circuit by taking them apart and cleaning and tightening or do a voltage drop test. Be careful of the connection at the starter. It is easy to damage the starter.

You'll need to replace the battery unfortunately.

[dropstharockalot]

Figured the battery was a gonner... bummed about that.

I'll try to work through the starter circut like you said... I'd love to find a bad connection or wire instead of having to get a whole new starter installed.  Given that I had the bike apart for the carbs, it's possible I didn't get something back together tightly.

Is it possible that the LED taillight is the culprit, or is that just not going to provide enough resistance for the dramatic damage to the battery?  I'm not doubting your diagnosis - however, none of these problems cropped up before installing that tail light earlier this year.

[ducpainter]

Figured the battery was a gonner... bummed about that.

I'll try to work through the starter circut like you said... I'd love to find a bad connection or wire instead of having to get a whole new starter installed.  Given that I had the bike apart for the carbs, it's possible I didn't get something back together tightly.

Is it possible that the LED taillight is the culprit, or is that just not going to provide enough resistance for the dramatic damage to the battery?  I'm not doubting your diagnosis - however, none of these problems cropped up before installing that tail light earlier this year.

I don't think that tail light could possibly draw enough to cause that type of damage to the terminals.

Usually, I'd agree that the last thing you messed with was the culprit, but... the much lighter gauge wiring to the light would melt first, or you'd blow a fuse.

I'm pretty sure the issue is in the starter circuit.

[Langanobob]

Or, the battery terminal connections themselves were loose and generated a lot of heat due to their own resistance.  But it seems unlikely that both battery terminal connections would've been bad.

[bikepilot]

It would be really weird for the battery terminal connections to be the highest resistance point in the circuit between the battery and starter if the cables were clean and tight (meaning the terminals shouldn't have melted if the cables were clean and tight).  I'd triple-check that the cables at the battery terminals were clean, tight and making a good connection.  Something is a bit weird there. Even if the starter were pulling too much juice the terminals aren't what would normally die first.

The only way to pull enough current to melt big stuff like that is the starter or a short in the starter circuit.  Tail light, head light etc even if shorted wouldn't do that as the fuses would pop way before the terminals melted (and if they didn't the wires would fry).

[dropstharockalot]

I don't recall the bolts coming off any easier than usual when I removed them... other than that memory I can't really check the tightness of the bolt connections at the terminal, since I pulled the bolts when I discovered teh damage and haven't put them back.

Thought... I did have new bolts holding the connections to the terminals, as one of my old bolts "escaped" during my re-assembly after doing the carbs.  I replaced them with cap head bolts from the local hardware store wall-of-bins-full-of-fasteners, along with matching nuts.  Is it possible that I picked nuts and bolts of a material that caused this problem (hardening/coating/treatment that impeded current flow / added resistance?).






///Please don't answer "yes," because then I'll have to smack myself with a phonebook for roaching a $110 battery with $1.28 worth of fasteners...

[Howie]

I don't recall the bolts coming off any easier than usual when I removed them... other than that memory I can't really check the tightness of the bolt connections at the terminal, since I pulled the bolts when I discovered teh damage and haven't put them back.

Thought... I did have new bolts holding the connections to the terminals, as one of my old bolts "escaped" during my re-assembly after doing the carbs.  I replaced them with cap head bolts from the local hardware store wall-of-bins-full-of-fasteners, along with matching nuts.  Is it possible that I picked nuts and bolts of a material that caused this problem (hardening/coating/treatment that impeded current flow / added resistance?).






///Please don't answer "yes," because then I'll have to smack myself with a phonebook for roaching a $110 battery with $1.28 worth of fasteners...

Yes (sorry).  Overheating will happen where the resistance was the highest.  Don't smack yourself with that phone book.  We have all did things much dumber.  Ever install an automatic transmission, look down and see the the torque converter sitting on the floor right in front of you?  I did.  And I've done dumber.

[dropstharockalot]

Crap.

I mean, thanks.  For future reference, what types of materials and finishes should I be looking to avoid?  What types of hardware do I need?



Also, does anyone have any experience with this type of set-up:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150518639775&viewitem=&sspagename=STRK%3AMEWAX%3AIT

I'm a cheap bastard, but the kit's not to spendy and I hate the idea of electrical gremlins stranding me even more than the idea of laying out some coin... ounce of prevention, etc... etc... much of what they've got in their write-up seems to mesh with the info in this thread and a couple other starter-related threads on the board.

Thanks again for all the help in this thread.

[bikepilot]

If the bolts held the cable tight against the led post its unlikely they are to blame, but its best to use those bolts that come with the new batery (and if you loose those, clean up and re-use the ones from the old battery).  Make super-sure the cable surface where it fits against the terminal is clean and in good shape - a bit of steel wool, a wire brush or fine emery cloth is helpful here.  Re-install with a bit of dielectric grease on stuff to help keep corrosion at bay. Maybe the bolts weren't quite a good fit and the cable wasn't clamped tightly against the post.

I haven't used the product in the ebay link, but have heard good things about the seller.  Other than a small weight increase you can't go wrong with larger wiring - reduces resistance, stays cooler and keeps everything happier.

Also note that if the battery gets low and you keep cranking the bike over things get hotter (less volts means more amps means more heat) so make sure to keep the battery charged up and in good shape.

I think for my next battery I'm going to try a shori (sp?  - there's a big thread on them).  ~ 9lbs weight savings there and they are supposed to hold a charge longer.  There's a vendor on advrider.com that sells them and offers discounts.  We may have a vender here too - I'm not sure but check first if you go that route 

[Howie]

If the bolts held the cable tight against the led post its unlikely they are to blame, but its best to use those bolts that come with the new batery (and if you loose those, clean up and re-use the ones from the old battery).  Make super-sure the cable surface where it fits against the terminal is clean and in good shape - a bit of steel wool, a wire brush or fine emery cloth is helpful here.  Re-install with a bit of dielectric grease on stuff to help keep corrosion at bay. Maybe the bolts weren't quite a good fit and the cable wasn't clamped tightly against the post.

I haven't used the product in the ebay link, but have heard good things about the seller.  Other than a small weight increase you can't go wrong with larger wiring - reduces resistance, stays cooler and keeps everything happier.
<snip>

Agreed, I can't think of a metal that wouldn't be a good enough conductor.  Even if plastic fasteners were used there probably would have been enough contact area.  My guess is the fasteners themselves were tight, but there was an air gap and some arcing going on.

If I needed new cables I would  do an upgrade.  That kit is nice, but pricy.  You might try theses folks:
   http://www.powerlet.com/

[dropstharockalot]

All right, gonna start with the new battery.  Special attention will be paid to the connections to ensure there are no gaps.  Hopefully that sorts things out.  I'll also be giving a thorough once-over to anything that was removed during the carb work to make sure I haven't failed to reconnect something properly.

Should the problem persist, I'll do the Volt Drop Test. If the VDT finds a bad wire, I can try replacement through the powerlet site (thanks for the link!).  If the problem is bigger and involves the starter, it's probably off to the dealership

The mention of the Shorai (sp?) battery got me thinking about one of those sealed gel units... anyone know if a standard Battery Tender will work for a gel battery, or will I need to invest in one of the gel-specific tenders?  I'm loving the idea of a mail-order battery for some reason...

[ducpainter]

<snip>

The mention of the Shorai (sp?) battery got me thinking about one of those sealed gel units... anyone know if a standard Battery Tender will work for a gel battery, or will I need to invest in one of the gel-specific tenders?  I'm loving the idea of a mail-order battery for some reason...

I'm of the opinion that just about any lead acid battery will outlast any gel battery, and that dollar for dollar you'll save with the lead acid. You don't need to buy a Yuasa either. Just buy a true replacement for your YB-16-AL2 battery and not one of those overrated/undersized Walmart things.
YMMV.

[Langanobob]

All right, gonna start with the new battery.  Special attention will be paid to the connections to ensure there are no gaps.  Hopefully that sorts things out.  I'll also be giving a thorough once-over to anything that was removed during the carb work to make sure I haven't failed to reconnect something properly...

If the battery terminal lug connection got hot enough to melt the terminals it's pretty likely that the surface  of the lugs on the end of your battery wires are oxidized.  They should be cleaned up with Scotchbrite or something abrasive enough to make them shiny.  Or as you mentioned, get a new battery wiring kit.

Bob

[dropstharockalot]

If the battery terminal lug connection got hot enough to melt the terminals it's pretty likely that the surface  of the lugs on the end of your battery wires are oxidized.  They should be cleaned up with Scotchbrite or something abrasive enough to make them shiny.  Or as you mentioned, get a new battery wiring kit.

Bob

Followed up on this tonight... they were pretty well-coated with brown and grey funk.  Fifteen minutes with fine-grit sandpaper later and they're gleaming like new.  The diagnosis of the crappy connection and the bad contact is starting to sound more and more like the culprit.  I do believe I'll unbolt my ground cable tomorrow and look for similar fouling where it meets the frame, just in case. 

While I was at it I checked the connections to the coils, spark plugs, etc... all tight, all clean, nothing frayed or melted.

There will be no progress reports tomorrow due to Game Seven of a truly phenomenal Stanley Cup series.  Hopefully I'll have the battery by Thursday and I can get to the Voltage Load Drop testing.